Difference between revisions of "Nutrient Timing"

Revision as of 14:37, 4 June 2010

Recent research has revealed that when you eat can be more important for an athlete than what you eat. Timing your recovery nutrition correctly can…

• Reduce muscle damage
• Improve muscle recovery and rebuilding
• Increase glycogen stores
• Reduce body fat
• Mitigate immune system suppression

The book Nutrient Timing by John Ivy has provided a great summary of the research and is highly recommended.

1 Timing

After exercise, the muscles become sensitive to insulin. Insulin is a hormone that is released in response to a rise in blood sugar. It is often considered A Bad Thing, as it will normally cause the blood sugar to be stored as fat. However, after exercise, insulin will cause the blood sugar to be stored as glycogen in the muscles and cause protein to be used for muscle synthesis.

Without nutrient intake, the muscles' insulin sensitivity will decline after exercise, returning to normal levels in about 2 hours. (There is some evidence that the muscles will actually become insulin resistant if no nutrients are taken.) If nutrients are taken promptly after exercise, the sensitivity can continue for up to 4 hours.

2 During Exercise

Taking protein with carbohydrate can reduce the damage to muscles and support the immune system. The ratio of 1:4 protein to carbohydrate has been shown to be effective. I use Optimum Nutrition 100% Whey (Vanilla) mixed with Gatorade, which tastes pretty good. In warm weather, I will also add 1/4 tsp salt per quart to provide more electrolytes. My current drink is Fellrnr's Go Juice

3 Immediately after exercise

Taking a carbohydrate/protein mix immediately following exercise can help. John Ivy's book recommends 15 grams of whey protein with 50 grams of carbohydrate, providing 220-260 calories.

I find that this is not enough after my training, as I have typically burned 2000-3000 calories. I take 15g protein + 65g Gatorade immediately after exercise and again after about 15-30 minutes. Each serving provides 320 calories.

4 Post Exercise

From 1-4 hours after exercise, continued fueling can maintain the muscle's sensitivity to insulin. Using a ratio with more protein and less carbohydrate is generally recommended. John Ivy's book recommends 14 grams protein to 2-4 grams carbohydrate. I have been taking 24 grams of protein with 15-30 grams of Gatorade 2-4 times in this period, providing me with about 150-200 calories per serving.

5 Sustaining Recovery

From 4 hours after exercise to the beginning of the next session, the recommendation is to take sufficient protein to keep the body provided with the nutrients for muscle synthesis. There is some suggestion that slow digesting protein, such as casein, is more effective than whey.

6 Fellrnr's Experience

At the time of writing I have been experimenting with the nutrient timing approach for several weeks. I have been cautious, as increasing my calorie intake by more than 1000 calories per training day has the potential to add a pound of body fat per week.

• I am far hungrier after training with this approach. The carbohydrate/protein mixture seems to simulate my appetite quite dramatically.
• I feel the effects of a training run much less. I'm mentally more focused and physically less sore. Sometimes it almost feels like I've not been for a run.
• In the past, I suffer from a muzzy, thick headed feeling after particularly hard training run such as a sub-3 hour marathon distance. Using the nutrient timing approach I am much more 'normal', though I still feel the effects.
• My body weight has increased slightly over three weeks. My day to day weight can vary by several pounds which make accurate readings tough, but I would estimate I am about 1 pound heavier.
• The biggest surprise is that my body fat has decreased rather than increased. I am seeing this decrease using skin fold calipers, the mirror and the 'jeans fit' methods ;}
• I suspect my calorie intake for the rest of the day has decreased somewhat as my appetite has lowered. Following 'the end of overeating' has helped curb my excessive intake.
• Protein intake has gone from about 160-200 grams (2.5g/Kg-3.2g/Kg) to about 300 grams (4.8g/Kg) on training days. This is higher than the highest recommendations for protein intake. However, as a percentage of calories, this is probably somewhat reasonable (300 grams is 1200 calories, with a 4000 calorie diet is 30%).