Sunday, June 27, 2010

Fueling During Training and Racing Part 2

The last blog post I talked about some basic aspects to fueling during training and racing for just about any race. In this post I will discuss more specific aspects of training for longer distance events.

The carbohydrate is your body’s most efficient fuel source. It plays a role in both low and high intensity endurance activities. A 150-pound triathlete can store approximately 1800 calories of glycogen as carbohydrate. This can help you through about two hours of high intensity training or four hours of moderate-intensity training. Our body can also utilize fat and protein as fuel (in very small amounts) to support the moderate-intensity workouts, but our stores of this are not nearly enough to support the energy of 4+ hour training days you need carbohydrates.

Consuming carbohydrates during training longer than one hour can help performance by maintaining adequate blood sugar levels. Blood glucose is the main fuel source for your brain, and a well-nourished brain may improve your training focus and possibly decrease your perceived effort. During the later stages of long training sessions, when the body’s carbohydrate reserves are running low, the greatest contribution to improved performance is achieved through maintaining steady blood glucose levels. Carbohydrate intake during training cannot prevent the inevitable fatigue associated with Ironman training, but it can prolong its onset. I recently experienced not having enough blood glucose at my run with the devil in Las Vegas. I will talk about this later in this post.

It is also important to remember that fueling during training throughout the week will play a role in your longer workouts on the weekend. If you constantly under fuel during workouts throughout the week you will likely have sub par training for your longer workouts on the weekend. If your weekly training workouts are longer than 60-90 minutes you should use something other than just water. You should consume an electrolyte drink or sustained energy drink and gels for workouts over 90 minutes. If you are training for an Ironman and will have a big weekend of training you may want to consume a gel 45 minutes into a 90 minute workouts.

Everyone always asks me how much carbohydrates are needed during training and racing. This really depends on your weight and can have a pretty wide range. Scientific studies estimate the range of dietary carbohydrate at 30 to 60 grams per hour. Research has shown that the human body can only burn (oxidized) carbohydrates at a rate of 0.5 to 1 gram per minute. From practical “real world” experience, many athletes can tolerate amounts higher than this. Some people as high 100 grams (or about 400 calories per hour). This is likely dependant on the person and size of the person. The larger the person the more calories they can tolerate. Also keep in mind for shorter workouts you should always plan ahead and eat a healthy snack a few hours before your workout.

For training sessions lasting longer than 60-90 minutes, I recommend athletes strive for 45 to 75 grams of carbohydrate per hour. This can be divided in to two to four doses (consumed every 15 to 30 minutes). Smaller athletes should start at the lower, and larger athletes at the higher, end of the range. You can consume these through drinks, gels, and bars. I tell some athletes to time their drinking to minimize dehydration. On hotter days drink more frequent about every 10 minutes warmer days should be 15 to 30 minutes. All of this should be practiced in training to see what works best for each individual.

Your ability to tolerate or absorb a particular amount of carbohydrate may depend on the type of carbohydrate consumed, the intensity of activity, and your hydration status. For instance, some athletes can tolerate a high-glycemic, sucrose-based sports drink, while other individuals may better tolerate a lower-glycemic, maltodextrin-based drink. Keep in mind as training intensity increases the stomach’s ability to handle high-carbohydrate loads decreases. I am one of the individuals who can't tolerate sucrose based drinks and need to rely on maltodextrin-based drinks such as Heeds Sustained Energy Drink. This product has mostly maltodextrin as a source of carbohydrates and a little amount of protein. I still consume some sucrose based carbohydrates just not in my energy drink. I get the simple carbohydrates in my gels and cliff blocks. I find it works best for me to have the majority of my carbohydrates for longer distance events from maltodextrin source. It is still important to have some from sucrose based products.

One very big factor that will come into play is the weather. The heat will for sure play a factor in what you can absorb because if you are dehydrated this can become an issue on what you can tolerate. One thing I would highly discourage in an Ironman race is to fall for the buffet of things available on the run! I have known people that get to the run a see all the food and drink at the aide stations and forget what they did in training. They start trying a little of this and that and by the time they are at mile 13 they are puking. Stick to your plan and don't indulge in the buffet. Have a back up plan if you feel sick to your stomach and stick to that back up plan

When training and racing Ironman events it is important to try and take in the majority of your calories on the bike. I would always lean toward the high end of the guidelines on the bike because it is likely you will not be able to take in as much on the run. Race morning for longer races you should get up extra early. I know that would mean get up at 3 or 4, but lets face it who sleeps well the night before races anyway? You should try and consume a breakfast that is mostly carbohydrates and something your have consumed during training before workouts. Oatmeal, fruit, eggs or egg whites are all good suggestions. If you cant eat oatmeal before a race a bagel with a very small amount of peanut butter, piece of fruit, and eggs is another option. Brown rice mixed with egg whites and some fruit might be another option. My choice is a bagel with peanut butter and jelly, and a muscle milk protein shake. As I have said before everyone finds something that works best for them through trial and error!


For some crazy reason I wanted to attempt the 50 mile run here in Las Vegas yesterday. Calico Racing puts on a race called Run With The Devil and they have a 5K, 10K, 1/2 Marathon, Full Marathon and a 50 miler for all those crazy people like myself. I planned on doing the 50 miler. We started at 7am and I was on track for most of the first half of the run. I was feeling pretty good with only a little bit of stomach cramps. I have a history of having trouble with longer events in the heat. Why I thought this was a good idea I don't know. From mile 30-38 I was feeling the heat (maybe because it was about 105) and slowing down to a snails pace! I once had heat exhaustion at Ironman Arizona and it is a very frustrating feeling. Physically my legs could do it and my legs wanted to run. The effort to just walk was making it hard to breathe and making me feel winded. I felt the heat and was not able to eat or drink much. I had 12 miles to go and didn't feel like dying so I decided to stop. I was not able to take in hardly any carbohydrates during the run because it was so hot and I am sure this contributed to the feeling of lethargy that I had at mile 38. So if you learn anything from my experience it should be don't run when it is over 100 degree especially 50 miles! Everyone said I was nuts and I think maybe I was. I am so glad I can focus on shorter distances right now. Most of my rides, runs, and swims for the next few months will be less that an hour long.....imagine that! After training for Ironman St. George then this run I don't know what I will do with all my spare time. I have not lost the bug for Ironman training. I recently saw that they have a new Ironman race for next year in Texas. I have given it lots of thought and think that I am going to sign up for it. Here we come TEXAS!

1 comment:

  1. All I can say is that my admiration for your ability to push yourself has doubled. Wow.