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  Last updated: 8/8/2018

Implications for training and performance

So let's review the important basics from what we know about nutritional physiology as we work to develop a personalized program to decrease GI problems and maximize your potential with a carefully planned training and performance diet:

(additional information - Exercise and the Athlete - Presented at Sun Mountain Lodge 1/2004)

Is there an optimum diet for the cyclist??

There is overwhelming evidence that adequate dietary carbohydrates are needed for maximum performance. At least 10 grams per kilogram of body weight per day. What is unclear is whether more carbohydrate (beyond 600 to 700 grams per day) will provide additional benefits.(Note that it is the absolute amount of carbohydrates that appear to be important, not the % of total daily Calories that are carbohydrates).

And Fat?? If you are interested in multi day endurance events, there may be some advantage to several weeks of a moderate fat intake equivalent to 30% of total Calories. But there is no evidence this helps in single day, high performance (%VO2max greater than 60%) activities and there may be long term health consequences. As total Caloric needs increase, the only reason to consider a high fat (more than 15 to 20% of total Caloric needs) diet would be maintenance of a positive Caloric balance IF carbohydrates alone were not meeting the challenge.

And finally, there is NO evidence that more than 2 grams per kg per day of protein are beneficial in endurance, sprint, or power training/performance.

There are three additional practical points for the cyclist (or other athlete) to remember.

First, the body's normal liver and muscle glycogen will support the first 1 or 2 hours of exercise at 70% VO2 max. without any need for supplementation. And both a good training program to improve the form and muscle efficiency of the individual as well as riding (or exercising) at a reasonable pace will postpone the onset of glycogen depletion and fatigue.

Second is that taking in carbohydrates during the event provides an additional source of glucose "fuel" that will extend the length of time before glycogen depletion and the bonk occurs. This is most important in rides of greater than 2 hours duration.

As a general rule, the body can utilize 60 grams of ingested carbohydrate per hour to supplement muscle glycogen stores, and the stomach can handle between one and two quarts of fluid before nausea occurs. This does put an upper limit on carbohydrate supplementation during a ride but gives you some guidelines for developing your own re-fueling program. And there is no problem in using solid food supplements as well, as long as enough fluids are taken along with them.

One of the biggest mistakes riders make is not beginning to eat (or drink) their on-the-bike calories early enough in a long ride. They often wait until they begin to get hungry (almost at the bonk stage) to eat. Ideally you should begin your snacks at time 0 and then every 10 to 15 minutes during the remainder of the ride. This handy iphone app may be the answer for those of us that just can't seem to remember.

Finally, eating a high carbohydrate diet for several days prior to the event will maximize your internal glucose (glycogen) stores, and will prolong the duration of activity until fatigue occurs. (But it will not increase the muscle's maximum energy output during that time.)

Over the last 10 years there has been a notable interest in ultraendurance events. These include runs of more than 24 miles (ultramarathons), cycling events of 100 miles or more (double centuries), and combination events such as the Ironman triathlon. The principles of training nutrition are similar to those for any athletic event of 2 hours or more, with the exception that attempts to bend the "physiologic rules" outlined above have the potential for a much larger negative effect on performance.

However, it is possilbe that your riding goals may require different nutritional approaches. As the old adage sayw "One size doesn not fit all." The following question from a reader will illustrate the point.

Q. I started cycling seriously this year and fell in love with the sport. Being very competitive I want to get as close as possible to my full potential. When it comes to my weight I definitely feel as if I could shed few pounds, I am now 180 lbs. but I definitely have few extra pounds of body fat I need to lose (aiming towards the 170 lbs.) Most of my training is at night time when I have some time on my hands (working during the day). In your website I understood that eating carbohydrates at night is a big "no no" if you aiming to lose weight, yet in the Post Recovery Ride chapter you really emphasis that eating carbohydrates before and after hard training is very important.

With no carbohydrates at night, training as hard as I want/need at night is hard, in the last 2 days I've been eating only vegetables, eggs, tuna and no carbohydrates at night doesn't make me feel full before going to sleep, and even kind of weak. I definately don't want to do any damage to my body or slowing down my training due to improper diet. I guess my question is this, trying to lose few lbs. how should my diet look like considering my training schedule? - A

A. There are two strategies in conflict in your training program.

  1. Losing weight which means you should be in a Calorie (and Carbohydrate) deficit and thus may not have maximal carbohydrate stores in your muscles and liver to power performance at 100% VO2max.
  2. Wanting to maximize your performance.

Long term, if you want optimal performance on a ride (especially multiple day rides), you need to assure that you have adequate carbohydrate stores for the days ride on board. If it is to be a multiple day rice, you need to focus on repleting the Calories you expended after each days ride so you don't slowly become glycogen deficient over the seies of rides. If the ride is less than 1 - 1 1/2 hours a day, you won't need to be quite as focused.

But to lose weight, you want to be in a state of negative Calorie balance, and as a result, the muscles to be glycogen deficient so that your body is forced to convert fat into carbohydrates which you then use the next ride. However, when you are in negative Calorie (and carbohydrate) balance, you will not have completely replaced muscle glycogen and not feel as good when you ride, especially when you get up in the range of 70 - 100% of VO2max where carb Calories become much more important to fuel the muscles. As an example, a friend of mine using the South Beach diet (very low in carbs) said training was a real chore. But he did lose weight.

So you need to decide if losing weight is the goal, or training to your max while maintaining your current weight. This does not mean you cannot train and lose weight, just that you should then focus on longer, slower rides (to burn those extra Calories) with fewer intervals until you hit the weight goal.

Now, let's look the key elements in developing your own nutrition program to maximize your personal performance.

Questions on content or suggestions to improve this page are appreciated.

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