Thursday, August 28, 2008

Focus on recovery

One often neglected aspect of training is recovery. During hard exercise you damage your body. The damage is in some sense beneficial because it forces adaptation. You respond by building more and stronger tissues. You also adapt to fluid losses and energy shortages. There are however two caveats to adaptation.

One, this adaptation is not unlimited. You cannot keep going hard and expect to continually get stronger. There are serious limitations to what one can take and if you stress yourself too much and too often, you will suffer long term performance loss. In general, athletes tend to go too hard and think they are invincible, while sedentary folks are too afraid to work hard and properly stress their bodies.

The second caveat is that recovery takes time. You need to give yourself that time to recover. When you are growing up or when you are getting older, you need more recovery time between hard workouts. Recovery is also an individual trait. Some people recover better and faster than others. There isn't much you can do about this and forcing the issue will produce the opposite of what you want. Strict adherence to a cookie-cutter schedules sold on the web or in a book will not produce the desired results.

Everyone eventually needs a long break too. All cyclists in the Tour de France suffer from decreased performance in week three. That despite the weekly rest days. And while some fare better than others, all are in need of some extended rest near the end.

As with training, recovery is very discipline specific. Triathletes may recover from running by going for a swim. Often training plans include yoga or pilates, or weight lifting and stretching, or some other non-endurance, relaxation-enhancing activity. The main reason why this is inserted is because most athletes need more than one rest day a week during their peak training, but most would go bonkers if they had to sit around for more than one day.

Whatever you do, please allow sufficient time to recover from hard workouts. Always make sure you are well rested before starting a major workout, otherwise you won't be able to push hard and derive value from it. And even when you aim for year-round fitness, take a week off every once in a while.

Sunday, August 24, 2008

Garmin GPS

I think I was one of the first people I know to get a Garmin GPS. My motivation was simple: I wanted a speedometer for my new triathlon bike that did not have wires or pickups of any kind. No clutter. The Garmin seemed ideal for that purpose. All you need is to do is carry it with you in one form or another and get all the info you need. It even stores your route and parameters for later reference.

My first try-out for the Garmin was Ironman Arizona, and it worked spectacularly well there. I got it right before the race and never tried it anywhere else before. IM Arizona is in Tempe, AZ, and the bike course goes out in the desert from Tempe. Great exposure to the Southern skies as they say.

There was one minor glitch. Although the Garmin was new, it barely lasted for the duration of my ride. And I am pretty fast on the bike. By the time I rolled in it was already giving me warnings of a low battery. In subsequent races I would learn not to turn it on until after the swim. Unfortunately, that just adds another layer of complexity.

What I found next was not so good. Here in Berkeley, with all its wooded hills and narrow canyons, the Garmin did not perform nearly as well. Half the time, I ended up in the scenery or cutting out entire swaths of road. The worst was the altimeter. When the unit can't find a good signal, it switches to a built-in barometer and then altitude jumps of 3-500 ft are not uncommon. Parts of my rides looked so jittery you would think there was a major quake.

All those extras add up rather quickly and I often found my rides inflated by 10 or more miles, and the climbing by and extra 3-6,000 ft. I guess that is what beginning riders love!

Next came the download issue. I am an avid Mac user and refuse to buy a windows box or use one of the windows boxes my wife has. Garmin's website, motionbased kept having trouble with my Macintosh. They did fix some of it over time, but never quite enough to remove all the headaches. And then they delete all but the last 10 of your downloads unless you pay them a monthly fee. Go figure ! Why would I want to pay someone a retainer just to access my old data? And why do I need to be online to look at my data? It is a hassle really.

In short, the Garmin was just an endless array of little nuisance factors and in the end, I had enough and tried to sell it on eBay. But before that could go through, my teenage son picked it up for its "gadget appeal."

So here we are, several years later. My son still uses the Garmin from time to time. The glitches are better but many are still there. The tracking is much better and he hardly ever goes off road like I used to. The altitude is better too. But I suspect it is because motionbased corrects the data. They keep him on the road by using maps. That looks good but it is cheating. And what is the point of GPS if you end up using a map anyways?  How can you trust the values that way?

The device works best in open country, no hills to speak of, no trees, and certainly no narrow canyons. You better make sure it is fully charged before every ride and even then it won't last for a whole century, unless you plan to ride without stopping. The lap feature works but more often than not it just causes errors. The interface needs a lot of work and it is something only PC users can love.

Downloading is still a pain. They resolved the Mac issues but it takes forever. You have to wait to get your data, and sometimes you have to wait a long time. I can download all the data from my Ergomo (onto my computer by the way!) and get all the info I need before motionbased gets around to start "processing" the Garmin runs. 

You can keep rides on the device but the more rides you keep the slower the downloads go. Each time you download and process you move another one of your old rides out of reach (you only get to keep 10). I can keep hundreds of rides from my Ergomo on my computer for free. And I can access them anywhere, and anytime. I can get to the original raw data, as well as the processed data. And my Ergomo's battery is good for a week at least.

In short, I think the GPS is a bad deal. You get lousy battery life, a so-so user interface  (really needs some Steve Jobs here), a painstakingly slow download that can take hours, a very limited history (unless you want to keep paying them), a subset of features (unless you want to struggle with microsoft or read manuals or both), and worst of all, "massaged data" that you have no control over. The latter is by far the worst problem and one that should give you pause if nothing else. 

The positives are that you can see where you went. That is great if you happen to suffer from Alzheimer's disease, but I never have trouble remembering where I went. If you rely on the GPS though, you will never find your way again without it.

The trouble with GPS and other route-finding software is that it dumbs you down. You come to rely on it and then you can't remember how you got there. Like speed dial numbers. You friend is number 3, and that is all you remember. Come to a new phone and you are lost. The same applies to GPS. When the device runs out of juice or breaks, it leaves you stranded like a little kid in a foreign city. I know so many people with GPS in their cars, who can't find their local grocery store anymore. I think it is better to stay aware while you are alive. That way you get to enjoy it more.

As for training, the value is extremely limited. It is cool to fly over your route and get all that video-game entertainment, but most of that is a waste of time really. Better get on your bike and ride a bit more. 

On the other hand, if you are in it to impress your friends with cool gadgets, it might be something to consider;) Better to impress them with your riding though! More difficult perhaps but far more enjoyable in the end.

Thursday, August 21, 2008

Power meters

The latest fad in cycling is called the power meter. It is a rather fancy and expensive gadget that is de rigueur for anyone taking the sport seriously. There are three popular power meters on the market. The earliest, and the most expensive unit is called the SRM power meter. It uses sensors in a specialized crankarm-spider combo. The SRM unit has three versions but almost anyone uses the professional (intermediate) version. There is an amateur version that is cheaper and a science version that is more expensive. The more expensive the unit, the more gauges it has.

Next comes another German unit, called the Ergomo. It uses the spindle in the bottom bracket and features an optical, non-friction pickup. Ergomo is about half the price of the SRM professional. Third in line is PowerTap, a system that uses strain gauges in the rear axle as its pickup. Unlike SRM and Ergomo, PowerTap is tied to a special wheel. On the other hand, moving it from one bike to the next is as easy as switching the wheel. Depending on the type of wheel you choose, PowerTap is about the same price as Ergomo or somewhat more expensive.

Finally, Polar, the maker of heart rate monitors, offers a rather complex method that detects vibrations in the chain. That requires a more delicate setup with a sensor on the chainstay. It also requires additional sensors measuring cadence to be placed elsewhere. The main advantage of the Polar system is its price. It is half as expensive as the Ergomo and less than a quarter the price of SRM.

Despite the differences, all four systems perform about the same provided they are installed correctly. As mentioned before, the Polar system is the most finicky and the one that is most likely to develop problems.

Since powermeters are hardwired -the new SRM is wireless- there are few problems with reliability and reproducibility. Battery life is not great but acceptable. Apart from power, all systems display a variety of other useful information. That includes speed, cadence, heart rate -using a Polar strap-, calories burned, and other derived variables.

All devices store data at regular intervals for download and later analysis. Most come with, or are compatible with software packages to analyze training data and make comparisons with others.

For accurate results, powermeters need to be calibrated often. Few cyclists bother to do this, and in some cases it is easy to see why. Calibration procedures can be quite tricky and time-consuming. In general, the effect on data collected is not that great, but for those who rely on fancy data analyses and cross-compare with others, calibration is a must lest the results be meaningless.

One thing a power meter user quickly finds out is that estimating power under normal conditions is quite easy. Power output is a fairly steady affair for a given rider and much of the data collected overlaps to an amazing extent with previous runs on similar courses.

Because power is so easy to estimate based on speed and a few other parameters, iBike recently introduced a power meter that is not only a lot cheaper but also quite accurate. Rather than measuring power, it estimates it using a few key measurements such as speed, cadence, wind, and a few simple inputs such as rider and bike weight. Tests under real life conditions have shown it to be very close to SRM, Ergomo and other direct-measurement devices, in all but the most rare conditions.

Think before you buy. A power meter is, for now at least, a very expensive gadget that will provide minimal additional information. A great way to estimate your power output and to detect any improvements is to ride a flat course for a set distance and measure your time. Or take a long steady uphill at an even grade. These will give you a very accurate way to estimate your progress without having to pay $500 or more for a meter. And if you need to know your power, you can use a simple web-based calculator to get a fairly good estimate.

A great rule of thumb is that if you ride 20mph steady in no wind, you are generating about 175W. At 22 the output jumps to 200-220W.

Happy riding!

Wednesday, August 20, 2008

Bike fit

I was reading John Cobb's blog the other day and lo and behold, the master himself was lamenting the fact that he could not find a good and comfortable bike position. The man who fitted Lance and hundreds if not thousands of others could not find his sweet spot on a bicycle. The wizard had trouble with his own magic. And that should tell you something.

I need to say that, years ago at CaliforniaMan, John gave me a free fitting session two days before the race. He was standing around idly and we got to talk about biking and before I knew it he volunteered to take a look at my position. I got a free Cobb fit, I could not believe my luck. Many travel half way around the world to meet with John. 

Many people have commented on John's intuitive sense and his deep insight and I have to admit that I became a believer in those sixty minutes we spent working out details. My position improved dramatically. Unfortunately, and this needs to be said as well, changing one's position two days before a race is not a good a thing. I paid for it by barely being able to run.

Therein lie all the lessons of a good fit. 

First, remember to make sure you are comfortable. Endurance races are long events and comfort is at a premium. Within limits of course, and a bike will never feel as comfy as a couch. But if you opt for a distinctly poor position you will not reap any benefits from it, no matter how aero or how otherwise "correct" that position is.

Second, never make abrupt changes, and especially never change things in the days before a race. Even if the changes make sense and are for the better. You do not want to race using a new position even if that position is orders of magnitude better than your current one. The same rule applies to all things new: don't race with new shoes, new cleats, etc. You don't need surprises on race day. 

Third, fit is a personal thing. Some people are easy to please while others are never happy. Even some pros never stop "fiddling" with their bike fits. Eddy Merckx for one, was famous for constantly checking and fine-tuning his position. It is doubtful that such changes make any real difference and more likely these behaviors are just one way of dealing with pre-race jitters.

Fourth, almost any bike that isn't way too small or way too big can be tuned for a proper fit. If in doubt, smaller is usually better. It is lighter and stiffer and positions you lower so there is less wind resistance. All these properties matter a lot.

Fifth, unless you are a pro or have money to burn, you don't need a custom frame. Your body is far more adaptable than frame builders would have you believe. Remember that performance in endurance events is not limited by muscle but by your cardiovascular system. Talk about better power or better leverage is of very limited value. What matters most is not to compress your chest by pushing your diaphragm all the way up and to stay as aero as you can be while preventing it. Often the best position is a compromise. Too aero may lead to too much power loss.

Last but not least, a good fit is one that feels comfortable and looks clean. If your buddies tell you you look awkward, it is worth taking a look at your fit. Especially when you are slow or working excessively hard. Remember however, that some people always look awkward and that many have idiosyncrasies that deviate from the accepted "norm" yet they perform at a very high level. If that is the case, chances are you will be better off to keep doing what you have been doing all along.

Happy fit!

Monday, August 18, 2008


Triathletes are a special kind. Most come from swimming or running backgrounds. Very few were cyclists like me. It is pretty obvious why. The cyclist body type is not well adapted to swimming -no arm or upper body muscle- and generally not well suited for running either -too much power muscle. Cyclists who ride in packs do a fair amount of anaerobic exercise. Pack riding is very nonlinear. When you're in the pack you can draft and go fast without burning too much energy. A pack moves at a pace that an individual rider cannot sustain for very long.

There is a great premium to staying in the pack while cycling. And that means you have to sprint a lot. Because packs accelerate and slow down continuously. They respond to attacks and breakaway attempts, and they slow down and speed up through turns (an accordion effect). Every time that happens you have to sprint. Distance runners hardly ever sprint. They are all about aerobic and sustained effort. No redlining here lest you want to pay for it later.

Because triathlon was "invented" by runners, the cycling they do is limited to time-trialing, i.e. no drafting allowed. Many people think this is to prevent cheating, i.e. you cannot benefit from other people's work, you have to do it all yourself. Even though it makes sense at first, it is clearly not the main reason. For one, triathletes draft in swimming. For another, pack riding is not necessarily any easier than solo riding. I actually think that most people would do worse overall if drafting was legal -that is different from sneaking in an opportunistic illegal draft.

If drafting were allowed, the whole dynamics of the race would change. Those who could form packs would move much quicker, so there would be a premium for sprinting to get into a pack. Once in there you would have to work hard on a regular basis. Then attacks would develop and you would have to respond. All that means a lot of anaerobic exercise. Not good if you have to run a marathon later.

Furthermore, the sport to concentrate on when completing a triathlon is the run. Here is the event that lasts long enough and moves slow enough that one can really gain or lose a lot of time. Cycling is too fast and too nonlinear to gain much time. Even though the biking leg is longer, it is pretty hard to make up 10 minutes here.

The swim is another event where you can lose or gain a lot of time. But unlike running, you either have it or you don't. If you don't, you may as well forget it.

According to a recent NYT article, triathletes are misfits who found a something to compete in. They are pretty good at everything but not good enough at any one thing to succeed at the top. Perhaps this can be phrased otherwise: triathletes are people with excellent cardiovascular fitness but they lack the specific body type or adaptations that would make them top competitors in a particular sport.

Sunday, August 17, 2008


Swimming is often a frustrating sport for triathletes. It is an area where many spend a lot of time and money without seeing any real progress. According to Ed Neely, a swim coach, many triathletes cannot keep the swim in perspective. They devote way too much time to it. He recommends that if your swim is less than 10% of your total iron-distance race, you should only spend 10% of your training for the swim. If you swim slower, he says, spend only 15%. If the blogs are to be believed, that is not what most people do.

Ed points out that "the correlation between swim performance and overall race time is poor, which means your swim time does not have a big impact on your placing." The event is simply too short to have a material impact on the race. But it can make all the difference if you are vying for one of those coveted Hawaii spots. I am a poor swimmer and I regularly finish in the last 1/3 of the swim. Since I often finish in the roll-down spots, my slow swims have definitely kept me from going to the Big Island. Therefore, I fully understand the desire to "do something about it." Five minutes would make all the difference for me.

What further confuses people is all the attention paid to technique. Technique implies something you can learn to master. There is no doubt that technique makes a big difference in Olympic swimming events, esp. when reaching for the wall touch. But such things matter little in long open water swims.

Humans are incredibly slow swimmers and water is a really dense medium. Any small amount of excess resistance can really slow you down. What we really are talking about here is slow and slower so efficiency is key.

For all the talk about Michael Phelps setting "a blistering pace," and "sprinting to gold," few people realize that the average adult could out-walk him without too much effort. And that is for short events. The "long swims" in this category are about 1/4 mile. For any real distance, a "speed" of 2.75 mph is considered world class.

Over the past five years I have watched a lot of swimmers, and learned a lot about swimming. Here are some things I learned.

1. Body type is the most important attribute of a swimmer. It is something you are born with and there isn't much you can do about it. It helps if you are tall, have a long torso with relatively short legs, big feet, a small head, and a wide arm-span.

2. Lie. Body type is the number one determinant of how you lie in the water. The flatter and higher you are the better but despite all the recommendations about keeping your head down, and pushing on your chest, etc. , your build is key. Some people stay flat even when their head is up, while others hang down despite their best efforts.

3. Muscle. Swimmers benefit the most from weight lifting. The more muscle you can pack on your upper body the faster you will swim. There is little or no penalty for the excess weight -many swimmers are overweight by athletic endurance standards- and more muscle means more power. The upper body is less subjected to gravity so "specialized training" such as weight lifting helps more here. Some swimmers look like weight lifters or wrestlers.

4. Body sense. People with better body sense, i.e. people who "instinctively" know where their body is in space tend to do better. But it is hard to see what is cause and what is effect. Good dancers make better swimmers.

Corollary: if you can get objective feedback (from a mirror or video) it can help a lot. Observers are not nearly as good. Many can tell you that you are doing something wrong, but very few can put their finger on it, or tell you how to correct it.

Some triathlon/open water guidelines:

5. Wetsuits. Wetsuits help but not all that much. They help the better swimmers more than the poor swimmers. You can gain about 5 minutes on an iron-distance leg. You can lose almost as much if you can't get out of the wetsuit. Still, better to wear one to keep warm unless the water is tropical.

6. Draft. Drafting is legal in (triathlon) swimming and it helps a lot.

7. Stay calm. Many people panic in a mass start. Then they run out of breath.

8. Swim straight and swim the shortest line. This is the area where the most gains are possible. It is also what fools most people into believing they can swim faster. As they become more comfortable, athletes start closer to the best line and further ahead (where it is more crowded), hence they swim shorter, straighter and get a better draft.

Everything about swimming is slow so it should not surprise you that swimming is a sport where making progress is agonizingly slow too. The rule is that once you can easily swim an iron-distance, you will also know your best swim time for the event. I.e. your gains after that will be minimal, even if you spend inordinate amounts of time in the pool, or spend inordinate amounts of money on coaching. As a matter of fact most of your gains later on will come from unrelated sources. Better draft, less current, less wind, straighter swim, shorter course (yes it happens, the opposite happens too believe me!), etc. all matter a lot more than your actual swim prowess.

Tuesday, August 12, 2008


When I first started cycling in the 1990's the mantra was, "you have to drink before you feel thirsty." Once you feel thirsty it is too late. The other common wisdom was that cramps were due to dehydration and that the best way to prevent cramps was to drink, a lot.

In the late 80's sports drinks started appearing on the scene. I remember the "introduction" of Cytomax and many cyclists asking how polylactate could prevent "the burn." Because another universally accepted truth was that lactate caused the burn. CytoMax was quickly followed by others and soon there are as many brands and types of sport drinks as there were sodas.

I quickly found out that I am a person who sweats a lot. I have rarely encountered people who sweat as much as I do, and I have found that people who complain that they sweat a lot, are often dry when I am dripping. It is quite possible that the sweating kept me from exercising when I was a teenager. I never liked exercise for some reason, and sweating may have had something to do with it. Esp. since I grew up in humid Belgium.

In any case, because I was essentially unprepared when I started cycling, I often experienced cramps. And because I sweat a lot, I quickly attributed these cramps to lack of fluids. And so started my drinking binge (drinking water and sports drinks that is). I would drink as much as my stomach would hold. Not right away, but over the course of three or four years. Then by 1994, I gave up on cycling.

A few years later, when I took up running, I was even more bothered by sweat. And again I often suffered cramps. Since I thought I was now "in better shape" the cramps had to be due to dehydration. What else was left? (Maybe not enough training?).

By then salt tablets had become universal too and I quickly got on the salt bandwagon. If I was drinking so much but still cramping, maybe the electrolytes were to blame? Many of my friends were so obsessed with electrolytes, and for some reason, with potassium (K+) that I finally started doubting the whole rationale. I can buy into Na+ losses, but K+? This did not jive with my training in human physiology and medicine.

I also noticed by reading bulletin boards and weblogs (another new thing) that I was not alone in this drink-as-much-as-you-can movement. Drinking and swallowing salt tablets became a way of life, not just for me but for others as well. And the more problems people experienced, the more prone they were to drink and eat salt.

But the running cramps persisted for quite a while. When I finally maxed out on salt tablets and even my friends started worrying about the health effects, it dawned on me that all this stuff was just hogwash. I had also heard more stories of runners who ran marathons without drinking and cyclists who would ride centuries on just one bottle. These were credible stories although the lead actors were mavericks of some sort. But if they could do it, it must be possible I thought. And it is.

Then I went to period of no drinking and no salt. That does not work too well either. It works for shorter runs (say less than 10 miles) or shorter rides (say less than 30) but that is it. If you go longer you need to drink something. But a whole lot less than most everyone recommends!

I also figured out that cramping has nothing to do with dehydration but everything with training. I was pleased to see that scientific studies support this idea. Sometimes I would be so dehydrated my voice changed and my face looked drawn, but no cramps. And then other times, it was quite chilly and I barely sweated but I did get cramps. 

I also noticed two other things: hyponatremia became a serious problem and even the media started picking it up. With all the emphasis on drinking, hyponatremia reared its ugly head. Hyponatremia is deadly. And drinking sports drinks does not cure it. The cure is to train and not to drink too much.

Hyponatremia is also an epidemic and the Boston Athletic Association (BAA) found that large numbers of Boston marathoners were in a state of subclinical hyponatremia. The more they looked at runners the more hyponatremia they found. They started issuing warnings.

I also noticed something else: less drinking and less salt works much better. My performance increased significantly. And perhaps more importantly, my comfort did too. No more upset stomachs, sloshing water, diarrhea bouts, potty breaks, and what have you. Also, no more time-robbing stops every mile. These days I barely drink for a marathon and never during the first half. The upshot? I don't have to stop for potty breaks, I don't have to stop to get drinks, I am no longer uncomfortable, and my finishing times have improved very significantly.

The take home message: think before you drink (and we are not talking alcohol here!)

Monday, August 11, 2008


According to the dictionary, electrolytes are the ionized or ionizable constituents of a living cell, bodily fluid, or other organic matter. To most endurance athletes electrolytes are tablets with names such as Lava Salts, Endurolytes, Salt Stick, eLoad, Nuun, etc., that you take while racing.

According to Jennifer Hutchinson, a dietician, nutritionist, and USAT Level 2 coach, "There is an endless debate on how much and what kind of electrolytes an endurance athlete needs, and whether or not electrolyte supplements are necessary."

Hammer Nutrition, maker of Endurolytes says its surveys indicate that successful athletes took in 3-6 Endurolytes, with 4 capsules being the most often reported dose. Endurolytes contain 40 mg of sodium, a moderate dose. Hammer also says, "Salt: less is best!" and recommends consuming less than 2,500 to 3,000 mg of sodium daily.

Let's review the important electrolytes in the body.

Two electrolytes play key roles in fluid balance. That is because these are abundant and exist as hydrated, or "surrounded by water" species. These two, sodium (Na+ and K+) can flow through specific pores in membranes or are pumped across those membranes by specific (energy consuming) pumps. These pumps make up a large part of what is called basal metabolism. The fluid content of a "compartment" such as the intracellular space (i.e. all the cells), or the intercellular fluid space, is effectively controlled by these electrolytes.

Sodium is the extracellular electrolyte. It is an alkali metal that is a component of table salt (or sodium chloride). Sodium is also the key component of any fluid secreted from the extracellular space, such as sweat. Blood makes up 1/4 of the extracellular fluid.

According to Hutchinson, Chris Leigh, a pro triathlete lost 2.2L of fluid per hour in a standard test at 70F or 21C. The fluid contained 1.5g Na/L and so his total loss was 3.3g per hour (3,300 mg). I have personally measured losses as high as 2.5-2.6L per hour. I never measured the Na content of my sweat but I have reason to believe it is high. I sweat a lot and my sweat is very salty. Amounts of fluid lost and Na content in fluid varies from one individual to the next.

Potassium is the "other" electrolyte. It maintains intracellular fluid levels. For that same reason K+ is plentiful in foods with high numbers of cells, such as fruits, vegetables, etc. A normal diet supplies potassium far in excess of what is needed. The amount of K+ lost in sweat is also very minimal (100-200 mg/L). Supplying extra K+ during exercise is of limited value. Excess blood K+ is toxic and the kidney has an enormous excess capacity to remove K+ lest it becomes dangerous. Unless you inject K+, which can be deadly, you need not worry about either too much or too little.

Two other electrolytes play key roles in the body. These are often added in supplements and as part of multi-vitamins. They are calcium (Ca++) and magnesium (Mg++). Ca++ is the mineral component of bone. Largely because of osteoporosis, calcium is added to anything and everything people can think of from juice to water, to tablets. That is ironic since Ca++ plays no role in osteoporosis and this fact has been well known in the medical community for decades. Yet everyone recommends women ingest a lot of calcium.

Calcium is also necessary for muscle contraction and nerve conduction. Yet excess intake before, during, or after exercise is a waste of time (and money). The amounts of calcium needed for these important functions are extremely minuscule. Furthermore, more than 1 kg (yes 1,000,000 mg) of calcium is freely available and in equilibrium with the blood. Excess calcium only leads to kidney calcification, kidney stones, and other unwanted and nasty side-effects.

Magnesium too is important for nerve function and muscle contraction. It is the fourth most common mineral in the body, with about 50% in the skeleton. Magnesium deficits are extremely rare and only occur in patients with genetic disorders, advanced kidney disease, and those taking diuretics.

Mg has been implicated in cramping and it is often added to supplements and drinks. There is no evidence to support this and it is extremely unlikely that anyone would suffer Mg deficits during a race. It is totally unlikely that oral Mg supplements could correct such deficits if they existed. Both calcium and magnesium for contraction and nerve conduction are highly sequestered in separate compartments with tightly controlled levels. Furthermore, there is evidence that fatigued muscle cells actually dump Ca and Mg in the extracellular fluid. Such active mechanisms cannot be counterbalanced by oral ingestion of minerals. In these cases oral intake just adds to the already increased plasma load and puts stress on the kidney.

The "negative" electrolytes such as Cl- and HCO3 are no less important than the positive ones However these are packaged along with the positive ones as NaCl or NaHCO3, etc. to maintain electrical neutrality. Bicarbonate is also in equilibrium with CO2, and respiration can quickly restore any imbalance.

In short, all that is needed during a long race is to replace some of the Na lost. It is probably best to replace the bare minimum. Contrary to what you hear all the time, electrolytes do not prevent or cure cramps. To prevent cramping make sure you train properly. Proper training will also mitigate any negative effects from fluid or electrolyte losses. Some amount of dehydration is normal during a long event. The better trained you are the less it will affect your performance. Replenishing during the race will only work if you are trained well. It will not make up for lack of training.

Thursday, August 7, 2008


Here is some food for thought. According to recent ad-publication I received I should not trust my regular diet. Entitled, "The balanced diet myth--shattered!" the publication goes on to warn me about inadequate micro-nutrients.

Wow! Now here is something to worry about? What if we can't get a balanced diet? And what is a balanced diet anyways? Where is the balance in all this?

To give credit where credit is due, there are a few truths here. For example, we read: "Did you know that there has never been a single clinical study that documents what comprises a balanced diet, nor one that has demonstrated one's ability to meet basic nutrient requirements through whole foods alone?" 

That is true as far as the "single study" goes. It would be hard to design a study like that. How do you measure balanced in any case? Most of what we know about diets comes from inadequacies and deficiencies. Ironically enough, most of those were uncovered when people tried to "engineer" artificial diets in order to improve performance. Deficits are rarely seen in common diets, and only when caloric intake is inadequate. The reason is simple: no diet could survive if it caused illness.

The second part is completely nonsensical. Clearly one is able to meet one's basic nutrient requirements through whole foods alone. That is what people have been doing for tens of thousands of years. More than that, they met their basic requirements and those of their offspring as well. If they hadn't we simply would not be here. The very fact that we are alive proves that our parents ate adequate diets that supported their daily needs for several decades and provided enough extras to produce and raise healthy offspring. Since mammals have long pregnancies that is not a trivial matter.

People in the past also did more physical work and hence put more demands on their diets than we do. No time to sit around on the couch watching TV. No chips to munch on. Nothing but whole foods alone. Real hard labor and long hours were the rule. No pushing paper in the office. No driving kids to school. Survival in past generations demanded a high level of physical fitness.

Studies on Greek triremes, a kind of warship driven by rowers, have shown that the men rowing the ship were every bit as fit as today's Olympic athletes. Given that these were ordinary citizens of Athens, chances are the real Greek athletes were even fitter. All without special nutritional supplements.

Warfare using swords and shields was a physically demanding and exhausting activity. It is widely believed that not too long ago, people walked the equivalent of a marathon each and every day. Pheidipides, the man of marathon fame, ran from Athens to Sparta, a distance of 147 miles through rough terrain, a few days before joining the Athenians at the battle of Marathon. (It is unlikely he ran the 40kms to Athens to bring the news of victory-after which he supposedly dropped dead, but that is another story. He did run the 147 though.)

In any case, my ad-publication tells me "Regular diets simply can't cover the entire range of vitamins, minerals, phytochemicals, antioxidants, and other micronutrients necessary to maintain optimal health and peak athletic performance."

There is every indication that the "regular" American diet, "unhealthy" as it is, does that and more. Clearly it contains ample supplies and lets people grow in all three dimensions. Furthermore, what makes the diet unhealthy is not a lack of items, but rather too much of them. The "regular" American diet is too high in carbohydrates for anyone's needs. But no American eating such diet suffers from lack of vitamins or minerals. 

If anything, Americans tend to suffer from hypervitaminoses due to all the vitamin pills they take. They eat too many minerals (esp. salt) and often suffer from mineral deposits instead. They do not lack phytochemicals or antioxidants either.

There is no reason to believe that "daily supplementation is a necessity, not an option," as my publication indicates. Furthermore, the daily supplementation I supposedly need consists of nothing but a cocktail of vitamins and unproven supplements and extracts whose consistency and quality is likely in doubt. Plant extracts are notoriously inconsistent in quality. The levels and types of ingredients vary from batch to batch and from season to season even under the strictest QA provisions. It is one reason FDA shies away from plant extracts.

And when it comes to clinical studies, the news is not good. Not a single study has ever shown the benefit of such extracts. Each and every time people have studied "promising" supplements in prospective studies, the results have been negative or detrimental. Promising cases include those where micro-nutrients were found to be correlated to health benefits in retrospective studies. You heard it all, vitamin E, vitamin C, lycopene, quercetin, etc. etc.

In prospective studies many of these ingredients caused or made worse the very diseases they were supposed to prevent or cure. I would advise you to stay away from such preparations. The benefit is not there and you run a very real risk of ingesting a banned substance without your knowledge. Unfortunately, when that happens you will be totally on your own. Not even a grain of sympathy will come your way. 

Tuesday, August 5, 2008

Intensity is key

A lot of amateur athletes work out diligently everyday. Yet they never seem to improve. It is of course possible that they have attained their all-time peak and that no further improvement is possible. Chances are however, that this is not the case. The reason people get stuck at a sub-optimal level is that many do not know how to train. They are happy to put in their hours every week but they do so in a routine manner. Too often they shy away from intensity. In general the older people get the more likely they are to avoid high intensity training. Yet without it, no significant improvement is possible.

Yes, you heard that right. To improve you need intensity and intensity hurts. You have to push yourself and doing so will hurt. It will hurt while you do it and it will hurt afterwards. It is not the type of stuff you want to do all the time, but it is essential preparation for racing. Far too often people are happy just to cover the miles, to do the time over and over again. Such a non-changing program will not produce results.

Race preparation requires distinctive steps. First you need to build a base. During this phase you ramp up slowly from where you are to where you want to be. You need to ramp up until you can cover the distance or at least 75-80% of it, without undue stress. That takes time. During this phase you don't need to go hard, you need to go long. Building a base is something you do in the off-season and you need to do it again every year. The more time you take off, the longer this phase will be. It is possible to stay in a state where you maintain a good base, but even then you should do a few long efforts at the start of your season.

Once you complete the base-building phase you need to add intensity. There are two types of intensity training: tempo and intervals.

When you start this phase, you first cut back on the length and distance of your workout. To compensate you up the intensity. Tempo is any swim, bike, run, row done at constant high speed. It is often called "race pace," and is done at slightly below or somewhat above the desired race speed. As always, you start out slower and get faster as time progresses. You also go longer. 

After a six to ten tempo sessions you should start to add in interval workouts. An interval workout is any workout that alternates high intensity with relative rest. A common prescription is seven to twelve high intensity bouts with some longer low intensity in-between. There are many variations on this theme and entire books have been written on just interval training. Yet the prescription is simple: warm-up, go hard, recover while keeping going, go hard again, and so on. For endurance the best intervals are slightly longer intervals done at 80-90% maximal effort. It is best to rest before an interval workout so you can go really hard when you have to.

From now on until race date, you need to alternate tempo, intervals, and rest. The closer you get to your peak week, the more intervals you need. Your peak week is one to two weeks before the actual race. After your peak week you reduce the amount of training, but not the intensity. It is called "a taper," and the longer your race and the more high impact, the more you need to taper. So you taper more for running than for biking or swimming.

It is important to insert plenty of rest. If you are not well rested you won't be able to hard during training. If you can't go hard, the training won't be as effective. You need not worry so much about a bit of extra rest. A few days of rest won't harm your performance. If anything, you may do better. Many athletes compete without adequate rest. The older you get the more rest you need. Take at least one day a week off, and rest two days before a major race. You will do better too.

Monday, August 4, 2008

More misconceptions

Lactate, the burn, and muscle pain

Lactate or lactic acid is a compound that is produced from pyruvate in a reaction that releases energy. It is also produced by bacteria and yeasts in a process called fermentation. When lactate production exceeds lactate clearance during heavy exercise, the plasma levels rise. This rise is known as the lactate threshold and is used as a measure of aerobic energy production capacity. Lactate levels can rise 10 to 20 fold during such bouts, but the increase does not cause acidification (acidosis) or the "burn." Neither does it cause the delayed onset muscle soreness that often follows such efforts.

The pH changes that accompany intense exercise are due to H ions released from ATP hydrolysis. ATP is an energy storing intermediate. The acidosis causes discomfort but it also allows easier oxygen transfer from the blood. 

Lactic acid is found in many fermented (or sour) milk products such as yoghurt, kefir, and cottage cheeses. It is also found in wheat beers. It is often used as an anti-oxidant and preservative. Lactic acid can be used as fuel by muscle cells and the liver uses it as a substrate for gluconeogenesis or glucose production.

Soreness, stretching

Delayed onset muscle soreness (DOMS), which occurs 24 to 72 hours after exercise is not caused by lactic acid and any lactic acid buildup quickly dissipates within minutes. The exact cause of DOMS is not known but it occurs frequently after extensive concentric contractions. It may be caused by inflammation and DOMS is often accompanied by some stiffness, swelling, and heat.  Concentric contractions are contractions that shorten muscle length. It may be one of the reasons why stretching (or excentric movement) is recommended. Elongated muscle has more power and some claim stretching increases power. This is nonsense as the elongation subsides as soon as the first contraction takes place. There is no lasting elongation benefit due to stretching.

Furthermore, studies have shown that stretching has no effect on the emergence or duration of soreness. Some studies even showed that excessive stretching may cause DOMS. There is also little evidence to support the claim that DOMS promotes muscle hypertrophy as is often rumored in body building circles.

Muscle hypertrophy is most likely caused by increased glycogen storage in type IIx fibers. Since glycogen is stored inside cells with an equivalent amount of water, even small excess amounts can contribute significant bulk. Sprinters and others engaged in anaerobic activity often sport bulky muscles. The athletes may note that after extensive efforts their muscles appear somewhat "deflated." 

Muscle definition

Muscle definition is most apparent in those with little or no skin fat. That is why women almost always lack good definition, especially in their extremities. Another enhancer is dehydration and body builders often used diuretics to promote dehydration before competition. 

Endurance athletes tend to be very lean and have low muscle mass. While more muscle means more power, it comes (literally) at a heavy price. The trade-off only makes sense in short events such as 100 and 200m dashes, and many swim competitions where excess weight is not an issue.

Endurance exercise on land is primarily limited by cardiac output, and excess muscle mass has a negative effect on performance. That is why weight lifting is not recommended. The increases in strength are easily offset by the excess weight. Even a little bit of extra upper body muscle can nullify a cyclist's chances at winning an event like the Tour de France, where climbing plays a significant role. Runners especially need to be very light if they are to have any likelihood of winning distance events.

Resupply (and massages)

It is often stated that endurance athletes need to resupply their bodies immediately after exercise. It is recommended that they ingest carbohydrates and protein as soon as possible to promote recovery. It has even been documented that muscle cells are more likely to pick up and store glucose in the forty minutes following intense exercise. All of this has led to many preparations and potions known as recovery drinks, recovery bars, and recovery supplements.

The reality is quite a bit different. Unless more exercise is planned in the next eight hours, there is no evidence that immediate refueling confers any advantage. It does not lead to more glycogen storage, stronger muscle, or to better and faster recovery. It does not promote faster healing if such healing is necessary (in almost all cases there is little healing to be done).

There is really no reason to expedite water or food intake. Doing so is likely to lead to excess intake in any case, as the body takes time to adjust. It is actually preferable to watch one's carbohydrate intake as it is easy to ingest 1,000 calories of carbs after intense exercise. That is way more carbohydrate than is needed. It is therefore much better to start eating normal foods as soon as possible.

There is absolutely no need for special drinks, bars or powders, even after intense long-duration exercise. Nor is there any evidence showing that such concoctions have any advantage over normal foods whatsoever.

Best is to drink some water, eat some fruit and get some rest. And a nice shower too. As  for massage, be my guest. Once again there is no evidence massage promotes recovery or prevents DOMS. If excessive soreness or inflammation is present it is better to avoid massage as it may do more harm than good. Ice is the better choice in those cases.

Massages are a feel-good hug whose effect is primarily if not exclusively psychological. A gentle rub tends to alleviate pain and soreness, but has little or no effect on healing or recovery. Feel free to indulge, but don't expect any wonders here. But then again, placebo is a very strong potion so you never know!

Sunday, August 3, 2008

Slow and fast twitch muscle myths

I read an article by top triathlete Samantha McGlone the other day. In it she discussed how a short-distance athlete can prepare for and adapt to iron-distance. She started out by highlighting her career as a short distance athlete and remarked how odd it was that she is doing so well in short events given her body type.

That body type, we were told did not have "a single fast-twitch muscle fiber" in it. Furthermore, Samantha claimed she knew this because tests had been performed and these tests had returned said result. The article further implied that short distance events, such as sprint and Olympic triathlons relied on fast twitch muscle, whereas longer distances were the purview of slow twitch muscle.

While I have great respect for Samantha and I certainly have to admit that she is a fantastic performer who could beat me anytime, there is no doubt she is sorely misinformed and her understanding of physiology is incorrect. In that respect however, she is not alone. The slow-fast twitch misconception is quite common among athletes and even some coaches and doctors. Along with the lactic acid buildup this is one of the most common misunderstandings in the sport.

Some background:
Mammals have three types of muscle, smooth, striated and cardiac. The latter is a special kind of striated muscle. The terminology (smooth, striated) refers to the transverse stripes seen under light microscopy. Smooth muscle has no stripes or striations, while the other types do. Smooth muscle is also known as involuntary muscle and it lines the gastro-intestinal tract, the blood vessels, the airways, the genito-urinary tract, and it is present in the hair follicles in the skin. It is not under conscious control. Smooth muscle can show burst of activity like other muscle, but most often it maintains near constant, quasi-permanent contractions that are responsible for the "tone" of various structures.

The heart is a pump made of muscle and connective tissue rings and patches. It is not under voluntary control either. It consists of special fibers that look somewhat similar to striated muscle. Heart muscle contracts in bursts like skeletal muscle does. The wall of any heart chamber works as a single unit with all cells contracting simultaneously. Heart muscle has an intrinsic rhythm and it contracts regularly even in the absence of outside stimuli.

Skeletal or striated muscle (so-called "meat") is voluntary, and consists of long thin cells, called fibers that are arranged in parallel bundles. Some cells can be as long as the muscle they are in. Skeletal muscle is connected to bone via specialized connective tissue called tendons. Most muscle contracts rapidly but some "postural" elements also maintain a certain tone and are less suited for rapid movement.

Skeletal muscle contracts in short bursts that alternate with longer relaxation periods. Functionally, the muscle is divided into "motor units" or groups of cells under the control of a single nerve fiber. There are thousands of motor units in a given muscle. There is also a range of small, intermediate and large motor units. Units work independently, and while some are active, others relax. As force requirements go up, more and larger units are recruited up to a maximal contraction. In maximal contractions, which can only be held for a few seconds, all units work together.

Muscle consists of two types of fibers, that have a different appearance. Type I, known as slow twitch, or red muscle is dense with blood vessels and consist of small fibers loaded with mitochondria and myoglobin. Mitochondria are specialized sub-cellular structures responsible for cellular oxygen use. Cells with high metabolism are packed densely with mitochondria.

Type I fibers contract rather slowly but they also tire slowly. They engage almost exclusively in aerobic power output. Myoglobin is an oxygen carrier protein similar to hemoglobin, the transport molecule in red cells. It is responsible for the red color. Type I fibers make up the dark meat common in beef, and chicken legs.

Type II fibers are fast twitch fibers. There are two subtypes, IIa, the aerobic fast twitch and IIb, the anaerobic fast twitch fibers. IIa has larger cells that appear reddish and contract faster than type I. They also tire more easily. Type IIb is known as white muscle because it has very little myoglobin or mitochondria and it is largely anaerobic. Its rate of contraction is very fast. Humans do not have IIb fibers, but they are common in small mammals whose flesh is white or pale.

Humans have an intermediate type of fiber, sometimes called IIx. It has less mitochondria and less myoglobin and can contract faster than type I. IIx tires quickly and can become painful quickly too. That pain is called the "burn" and is incorrectly attributed to a lactic acid buildup. It is quite clear however that the burn has little to do with lactic acid. Many manuscripts also incorrectly label these fibers as type IIb or fast twitch muscle. Humans do not have real fast twitch muscle.

Human muscle is about 50/50 type I and IIx, with some rather minor genetic differences between individuals. In theory, individuals with more IIx fibers would be better suited at anaerobic events such as the 100m sprint or weight lifting, whereas others with more type I fibers would be better endurance athletes. 

Note that in this context, any event that lasts more than 10-15 minutes is considered an "endurance" event favoring type I muscle. The time-frame of a sprint triathlon is many orders of magnitude greater than the time-frame used to describe the various muscle types and any connection between better performance on short versus long distance triathlons and the composition of one's muscle is pretty meaningless and irrelevant.

Saturday, August 2, 2008


There are two components to carbo-loading: exercise to deplete carbohydrate reserves, and carbohydrate ingestion. One without the other will not achieve the desired goal. To be effective carbo-loading should be done a few days before the actual event where it is needed.

Let's first review what carbo-loading is and why you would want to do it. Under normal circumstances, the body is fueled by free fatty acids, breakdown products of stored fat. All organs except the brain use free fatty acids. Only the brain has access to circulating glucose. The main exception to that rule occurs when insulin is present. Insulin is secreted when excess carbohydrate is available, as happens after a meal. Insulin promotes the use of carbohydrate by all active tissues and especially the conversion of carbs into fats. Working muscle can access small amounts of circulating glucose in the absence of insulin but the amount is rather insignificant. As a rule, muscle uses fats and internal glucose.

Fat is an ideal energy source, light and very efficient. Unfortunately fat cannot deliver quick bursts of energy. Fat utilization takes time. When fast delivery is required, carbohydrates are used. For very fast delivery, so-called intermediates like creatine phosphate are accessed. These are loaded by burning carbs and their supply is extremely limited.

In essence, we have fat for aerobic exercise and sugar for anaerobic bursts. Endurance racers get nearly all of their energy from fats. Training improves one's capacity to use fat. If at all possible, endurance racers should avoid anaerobic power utilization. However, even under the most aerobic conditions, a small amount of anaerobic power generation is happening. Even though it is small it is a major contributor to fatigue, especially when reserves run low.

Because muscle does not have access to blood glucose, it stores a small amount of glucose as glycogen within its fibers. To carbo-load means to push that storage to its maximum capacity. Athletes who rely on anaerobic power have well defined "big" muscle. Much of that bulk is due to stored glycogen and water in the so-called fast-twitch muscle. Despite all the hoopla about fast-twitch and slow-twitch muscle, humans do not have true fast-twitch fibers. But that is another story we will cover sometime later.

The main reason for carbo-loading is to increase endurance by making more glucose available to muscle. Muscle uses glucose for instant power delivery. As mentioned, even so-called aerobic exercise always involves a small amount of anaerobic output. We are trying to extend that capability. Muscle also uses a tiny amount of glucose to burn fat. It is unlikely that carbo-loading affects the latter mechanism.

Carbo-loading relies on a biological mechanism that kicks in when you deplete reserves. After depletion the body responds with excess storage. It is as if the body says, I won't let that happen again next time, so let's put in a little bit extra. Therefore, the first step in carbo-loading is to deplete reserves. To do so, you need to exercise hard.

The traditional method for carbo-loading works as follows. You eat no carbs (essentially an Atkins diet) for a week, while continuing to exercise hard. That is not a pleasant experience, especially towards the end of the week. Fortunately, after your last hard session you can overindulge in carbs for a day or two. That loads the muscle. Traditional carbo-loading is not something you want to do all the time. You should reserve it for special occasions.

In the modern method, which some claims is equally effective, you just exercise hard for a few days and eat lots of carbs. As long as you exercise hard and deplete reserves, the actual timing seems to matter very little and so you can eat carbs concurrently. 

In either case, because of the hard exercise, it is not something you do a day before the race. You may even wonder why you should do it in the week before. Don't you need to taper? You do. But the key is to exercise hard but not long. Remember the intensity matters, not the duration. You don't have a lot of glycogen storage to begin with. Glycogen storage is ninety minutes at most, and sixty seems a lot more likely. So a few brief intense bursts is all that is needed.

Because the traditional method involves eating no carbs, and hence only protein and fats, I have seen this method advertised as fat-loading. There is no such thing as fat-loading -in the sense of loading muscle with fat to increase its performance. The only fat loading is what most people practice (i.e. get fat) and it is not desirable. 

For the detail-oriented, it is true that muscle stores some internal fat, especially the so-called slow-twitch fibers. Nevertheless, fat loading is not needed. Fat can be produced internally from anything you eat (protein, carbs, fat), and the best method to accumulate fat is to eat carbohydrate as any meat producer will tell you. Remember corn-fed beef?

Happy carbo-loading.

Friday, August 1, 2008

Addicted to sweets

It seems the whole country is addicted to sweet. Anything and everything contains sugar or an equivalent amount of sweetener. From toothpaste to bread, mouthwash to electrolyte tablets, health drinks, chewing gum, and even supplements and vitamins, sweet is a ubiquitous presence. Many drinks that would be better plain such as ice-tea or ready-made coffee are nowhere to be found without the presence of plenty of sweetening.

America's addiction to sweets is as bad as its addiction to oil. Both are far more costly in terms of health and lives lost than the addictions the DEA is so obsessed with. Both are real addictions in need of serious attention.

Sugars (or carbohydrates) are an important energy source for athlete. That is because many activities demand high and immediate energy delivery. Virtually any athletic endeavor, except perhaps true endurance racing, requires a fair amount of anaerobic power. Anaerobic power is within the purview of sugar. Only sugars can provide a quick burst of energy.

Even though sugar storage is quite limited, uptake is very fast. Sugars are easy to digest and any sugar intake results in a quick change in blood sugar levels. Sugar intake is also virtually unlimited and sugars do not provoke a feeling of satiety. Furthermore, because digestion is so easy, stomach emptying is fast, thereby removing another natural halting mechanism.

Pure sugars are not that easy to find in nature and the energy required for foraging plus the other materials one needs to ingest to get to natural sugar may limit consumption in "the wild." However, humans have long since found a way to circumvent these obstacles. Human societies spend a lot of time producing or refining pure sugars. Nearly all human civilizations have stores of pure sugar available. These are often used as rewards or "candy," indicating a special role for such precious cargo.

Most societies have instituted rules to limit utilization. Kids are taught that eating too much candy will make them sick. It is doubtful that they would get sick (other than very obese) so the rule is meant to prevent over-consumption. Adults have similar rules and there is little doubt that the sugar-high and the sugar-jitters find their origins here. There are many tales cautioning people against eating too much sugar. 

Unfortunately, in our consumer society marketing groups quickly discovered that making things sweet sells more stuff more quickly and easily. These marketing groups wage a constant battle against common sense and societal prescriptions. They tout overindulgence and gorging. They make it look glamorous and hail it as a sign of success. No wonder then that more than half the country is overweight or obese.

Endurance athletes should be very careful with sugar intake. A diet high in carbohydrates is often recommended by coaches, consultants, magazines, and books. Although these experts will often propose complex carbohydrates and caution against simple sugars, there is little evidence that complex carbs are any better (or worse) than those "simple" sugars. All carbohydrate processing is very fast and any "long term" sustenance due to uptake or processing is probably a figment of people's imagination.

One should be especially weary of so-called carbo-loading meals. Almost all events have added carbo-loading meals the night before the race. Participants have come to expect such dinners and are often shocked when none is planned. Unfortunately, these carbo-loading dinners are anything but. First off, it is not possible to carbo-load in this manner, and carbo-loading the night before a race is out of the question. Second, the meals offered are rarely any different in composition from normal meals one can find in restaurants. They are not suitable for carbo-loading.

As Olympian Jeff Galloway pointed out, so-called carbo-loading dinners are often an excuse to eat too much. Eating too much has a negative effect on performance, and more so if it is done the night before. Many people no doubt feel they can afford to eat a bit extra, but it is the wrong thing to do. If anything, one should eat less before a race. Endurance events rely on stored fats and all of us (including those very skinny individuals) have enough fats to complete several races many times over. There is little need to add extra fat the night before.

Athletes should also be careful with carbs after training or racing. We are often told to replenish our glycogen stores quickly. We are told there is a time after exercise when muscle is especially likely to take up carbs. While that is true, there is little need to rush or to eat extra carbs right after the race. Even though muscle is more sensitive to glucose in the first 40 minutes after exercise, replenishment will still be adequate if no sugar is consumed within that time-frame. Within a day or two, there will be no difference between a person who ate carbs right away and someone who didn't.

There is a real danger however, of eating too much. Especially when the athlete reloads with carbohydrates only. One can consume a 1,000 calories of sugar faster than one realizes. And still feel hungry afterwards too.

The take-home is simple: be careful with carbs. Watch what you eat.