Nutrition Tips
As part of my Winter Cleaning on this website, I am consolidating content in the blog. Here is an article on nutrition that I wrote last year. Enjoy!
Nutrition
There is a lot of info out there around nutrition but here are the basic principles that I try to follow.
Day to Day
I recently read a great book by Loren Cordain and Joe Friel called “The Paleo Diet for Endurance Athletes.” Cordain has studied the diets of Paleolithic man and wrote some kind of bestseller diet book around the findings. The basic idea is that humans evolved on a diet of lean meats, high-fiber vegetables and occasional fruits. Bread, dairy and farm-raised meat weren’t available. The Paleo Diet suggests that you build your diet around lean protein sources and vegetables, which I've tried to do. The “for endurance athletes” part of it tries to address the carbohydrate needs of endurance athletes. It turns out that most of the carb needs are focused during & after exercise. So as much as I love baked goods I have been trying to cut back a lot when I’m not actively training or “recovery eating” from a difficult session.
During Training
While you can burn upwards of 1000 cal/hr you can only process about 1g of carbohydrate per kg of body weight, at least while exercising. Given that I weight about a buck and a half (150lbs or 70kg), one bar per hour comes pretty close to meeting my nutritional needs. A clif bar has about 250 calories, roughly 200 of which comes from the 45-50g of carbohydrate. Doing the math now, I should probably be shooting for 1.5 bars/hr if I am only drinking water (which is the norm now thanks to my dental hygienist).
To figure out how much fluid to consume, the best idea out there is to do a “sweat test.” Shoot for a day where conditions are similar to your “A” race conditions, if possible. Get naked and weigh yourself on a scale before the workout. Carefully fill your bottles and note how much fluid you put in ‘em. Then go out and do a workout whose length approximates that of your “A” race, hydrating as much as you think is necessary. When you’re done, get naked and weigh yourself again. Add that weight loss (and you will lose weight) to the amount of water you drank and you’ll get an idea of your sweat loss during that workout. Tom tells me that even a 2% reduction in weight due to fluid loss can lead to reduced performance. Basically your blood gets thicker and your heart has to work harder to pump this thick blood. I would expect this to lead to two things:
· a reduced heart rate & less delivery of oxygen to working muscles
· increased body/muscle temperature as heat isn’t moved to the skin as frequently
During & after training are the times when you get to binge on high glycemic foods – energy gels, sports drinks, bars, juices, even candy. It is important to get the sugar into your bloodstream and to the working muscles quickly. Note that this should be the opposite of your approach during meals and snacks. For this reason you want to avoid fiber and fat if you can help it. But… research (by the guys who sell Accelerade but also by independent researchers like the late Ed Burke & colleagues) shows that consuming protein during exercises reduces muscle damage and recovery time, letting you come back harder in our next workout(s). Although this will reduce the glycemic index of what you eat, the trade off is worth it. Fats are a more interesting story – I’ve heard people say that consuming fat while riding encourages your body to rely on fat stores a bit longer but that mat be bunk. I’ve heard similar things about caffeine consumption while exercising.
I’ve gotten good/responsible about consuming calories & fluid while biking but swimming and running are a bit tougher. You can’t really eat in the pool (although you can use an energy drink) and I don’t like carrying water while I run (and most training foods need a bit of water). The studies I’ve read tend to confirm that it is more difficult to ingest solid foods on the run than on the bike. Many stomach issues on the run leg of a triathlon are due to the athlete jamming food into a stomach that has “shut itself off” (more on this in the racing section). I recommend that you play around with less difficult calorie sources like gels & drinks, although you can still face this issue…
Recovery
Training tears the body down. Recovery is where you rebuild and get stronger.
After any hard or long workout, it is important to start replenishing fluids and muscle glycogen as quickly as possible. Most research that I have read suggests taking in about 1g of high glycemic carbohydrate per kg of body mass within 30 minutes of the end of your training session. Research also supports including some protein in this recovery meal -- a ratio of about 4g carbohydrate to 1g protein is a good target. Drinks are preferred to solid food for two reasons:
you are almost certainly a bit dehydrated after your workout
you will start absorbing the nutrition faster, especially is your stomach isn't all that happy with you after a hard workout
Off-the-shelf recovery beverages are excellent for this purpose. I tend to use Endurox most of the time (tangy orange flavor, mmm-hmmm) but recently I've been using Clif Shot recovery drink, too.
Race Day / Lead-up
Most of us are familiar with the term “carbo loading.” We always had pasta feeds the night before my big swim meets and rowing races growing up. The basic idea is to top off your muscle glycogen stores before competition. A kinesiologist friend of mine told us to “consume 600-800g of CHO” the day before our big race. I’ve seen grams-per-kg-of-body-weight recommendations in a few books & articles, too… My sense is that you should eat more carbs leading up to a race, especially if you’ve been on a lower-carb (or at least lower-processed carb) diet like Cordain & others recommend. But you don’t need to totally gorge. Based on my experiences, the best tips I can give for pre-race nutrition are:
· The day(s) before: don’t eat stuff that will still be in your gut during the race. This means cutting out fiber & fat and focusing on quickly-digestable carbs.
· Eat a before-bedtime snack the night before to ensure that you top off muscle & liver glycogen stores.
· Don’t eat too much the morning of your race! In fact, don’t eat anything for 2-3 hours before the race starts. For a long race (Ironman) it may be worth getting up in the middle of the night to have a snack/breakfast. For shorter races you are often better off eating nothing the morning of rather than chowing down 90 minutes before the race and feeling that familiar sloshing feeling during the run. I try to be awake at least 3 hours before my race and quickly eat my normal (or slightly smaller than normal breakfast). I may experiment a bit this year as I’ve gotten in the habit of running on a full stomach every morning but I wouldn’t recommend this approach.
· If you want to have a pre-race gel, wait until <15 minutes before the start of the race. Studies have shown that earlier consumption of high-glycemic carbohydrate will cause your blood suger to drop precipitously at just the moment when you don’t want it to! I’m curious how these studies account for warm-up, though… once you’ve started warming up, couldn’t you say that you’re in a “during exercise” state as opposed to a “pre-exercise” state?
During a Race
The simplest and most common guideline for eating/drinking during races is “don’t try anything that you haven’t tried successfully in training.” A less popular corollary is “you’re body will be a lot more hyped up during a race and may reject something that worked in training. Ideally you should test out your nutrition strategy in “B” races and hard workouts to reduce your risk of a Nutrition Disaster during your “A” race.” Quite a corollary, eh?
Gastric Emptying is another great concept to be aware of. Basically your stomach will stop emptying itself during periods of intense activity if you don’t keep something in there for it to work on. Tom says that thirty minutes is an important cutoff. Given that I don’t recommend eating before a race, the answer is to drink some water as close to your start time as possible. Having a disposable plastic bottle with you in the staging area is great. The other half is to start eating/drinking as soon as possible once you start the bike leg. At the Cascade’s Edge race in 2006, I waited to drink Accelerade until my HR “settled down” and ended up waiting Until 30-40 minutes into the bike. When I finally did drink, I found that I became a bit uncomfortable and struggled with a bit of gastronomical discomfort through the beginning of the run, too. My problem was that my stomach had put up its “see you after the race” sign once I went an hour without filling it. Don’t let this happen to you!
Feedback
A lot of this was stream-of-consciousness so let me know if you’d like me to elaborate a bit or if you vehemently disagree with something I said. I encourage you to ask via my blog comments so that others can see the discussion, although I will probably roll the ideas in to this article, too.
Happy training!