Note: Be sure to read the first post on nutrition. This second post incorporates technical data & information is from the USATF Podium Education Program session presented by Jackie Berning PHD, RD, University of Colorado, Colorado Springs. She has also been the nutrition advisor for the Denver Broncos & Cleveland Indians.
It is undeniable that poor nutritional status yeilds increased illnesses and prolonged or delayed recovery periods from workouts. Researchers have found that nutritional status in fact may be the reason for athletes feeling poorly or doing poorly. The point is that it may not be the training, or even over-training that is the issue. It may be a fueling-refueling issue behind it.
There are two distinct issues:
1. Post event eating which optimally occurs within 30 minutes of the end of working out.
2. Recovery nutrition which occurs between practices/competitions/rest days with the goal of replenishing fuels for good health & performance.
Depleted glycogen stores leads to muscle breakdown and an increased risk of injury. A lack of vitamins and minerals also play a role. During training periods it is critical to spread calories throughout the day; and the heavier the training the more important it becomes.
There was an interesting 16 week study of college athletes. (First of interest is that the study was not done on mice, sedentary or novice athletes. Therefore far more relevant to seasoned and serious runners.) The study included breakfast eating and non-breakfast eating groups. At the end of 16 weeks those who skipped breakfasts; ate light during the day and took in most calories later in the day, ended up with a higher percent body fat. This, even though they weighed the same at the end of 16 weeks! They did not gain weight, they gained fat which can only happen by losing muscle (or lean)mass.
When we are in a negative energy balance (that is, we are using more than taking in); protein is taken from body in those periods for energy (not fat) and so we lose muscle mass. What most people do not realize is that you can only burn fat if calories are coming in, not when you are starving yourself… even for relatively short periods (i.e. portions of days such as all morning without breakfast). This is NOT about adding calories through eating meals and snacks; it is a distribution of existing calories so that you end with a total even energy balance at the end of the day.
The athletes in this same 16 week study who had a “dispersed energy intake plan” (5-6 eating sessions per day) ended the study with lowered body fat percentage – though they also maintained the same weight. They provided a regular fuel source to do their workouts. This in turn reduced fat stores. It also increased muscle mass which also contributes to lower fat stores.
It takes 24-36 hours to replace muscle energy (glycogen). By consuming carbohydrates within 30 mintues post exercise you can reload your muscles in 12-16 hours. If you miss that 30 minute window, replenishment time is lengthened. There are enzymes that promote absorption in the muscles which are highest right after workout.
The goal is to replenish with .75 to 1.0 gms per kg of body weight. This can often be obtained with an energy bar plus replacement drink. If you do multiple workouts in a day you should do this after each workout if there is more than 30 minutes between exercise bouts. The recommended ratio is 4 parts carbohydrate and 1 part protein. The protein does not help glycogen replenishment; but repairs some muscle fibers. If you want a nice 4:1 ratio drink… it’s chocolate milk!
As far as good replenishment foods using either carbohydrates or carbohydrates with protein are OK. Some examples of good choices:
nutrition shake, smoothie, peanut butter sandwich, energy bar, yogurt, turkey sandwich. Variety is important to prevent boredom so be creative and vary the tastes. It is clearly unfounded to recommend eating more protein during restoration. There is no support for protein or amino acid supplementation. It does not enhance recovery or rebuilding of muscle tissue beyond what our normal diets do. (Caveat: this is not necesarily true for restrictive diets, vegetarians, etc.)
Tidbit: Regarding the glycemic index: stick to low glycemic index foods for anyone who is prone to gaining weight (i.e. throwers, linemen).
Here are some other tips from the experts.
You must practice nutrition during your conditioning phase. Do not wait until the competition season. You must test and experiment with timing of eating and fluids. Practice eating and drinking. Also, plan on environmental issues affecting your appetite (heat).
Here are some important takeaways.
- This is the advice being given to world class athletes with workouts that are far more rigorous than virtually all age-group runners.
- If these world class athletes are being advised not to supplement diets with protein and amino acids, neither should we.
- Spread your calories out over the day.
- Eat breakfast.
- Eat within 30 minutes after workouts.
- Keep diets that are predominantly carbohydrates.
Filed under: Nutrition, Science & Running, Training Effectiveness