Last month’s article began discussing nutrient timing for optimal recovery. The current recommendations for carbohydrate intake was addressed, leaving this month to present protein’s role in post-exercise nutrition.
When combined with a carbohydrate, protein intake maximizes the body’s ability to recover from exercise. The combination of carbohydrate and protein in the post-exercise meal boosts glycogen synthesis more than a carbohydrate does alone. With the addition of protein, blood insulin levels may rise more as well. As mentioned last month, higher insulin levels and glycogen synthesis help promote the anabolic state. Furthermore, because the presence of protein helps maximize muscle glycogen stores, protein consumption during the metabolic window allows individuals to consume fewer carbohydrate calories.
Studies in both resistance and endurance exercise have shown that a carbohydrate plus protein meal post-exercise benefits muscle repair. One study demonstrated that subsequent exercise performance, after a 4 hour recovery period from the original exercise performance, improved in the carbohydrate plus protein group compared to the carbohydrate and placebo group.
Protein can be an expensive addition to the post-exercise meal, therefore, the amount of protein necessary for optimal exercise recovery is a consideration. Researchers have found that optimal muscle protein synthesis occurs with 20 grams of post-exercise in men of average weight (173 – 206 lbs.). However, is this protein intake level optimal for all active individuals?
Women have also been tested, with similar results. However, individuals with significantly higher than average muscle mass or those who want to build muscle and have lower body fat may need additional protein. Older or aging individuals may also need extra protein. As we age, muscle mass is naturally lost in a process know as sarcopenia. Losses can be 8% – 10% or greater per decade, starting at around age 50. Regular exercise and high protein intake can slow the rate of muscle loss as we age.
The quality of protein ingested is another factor affecting exercise recovery. Gains tend to be lower quality proteins while milk, chicken, fish, soy and vegetable proteins are higher quality. Commonly ingested proteins are whey, casein and soy. Whey protein contains a higher level of important amino acids (branch chain amino acids) compared with soy and casein. Because whey is also ingested and absorbed more rapidly, it produces a higher rate of muscle synthesis at rest and after exercise. Soy is digested faster than casein, so soy protein produces higher rates of muscle protein synthesis at rest and after exercise than casein. Since both whey and soy are more rapidly digested that casein, they both are better able to quickly stimulate muscle protein synthesis during recovery. Nevertheless, casein is still a high quality protein. It is digested more slowly and takes longer to produce results. Currently, other vegetable proteins, like pea protein, are being investigated as good sources of protein. Pea protein has a similar amino acid profile to that of soy and is digested in a similar way and at the same rate. Complementary proteins are needed n the diet to achieve a balanced amino acid profile.
How do you utilize the information presented in this article? Research supports the notion that an optimal post-exercise meal for exercise recovery contains both carbohydrates and proteins, with 20-25 grams of whey protein and a 3:1 or 4:1 carbohydrate to protein ratio. With taking calories into account, a 2:1 ratio of carbohydrate to protein is probably where most athletes will be comfortable.
Post-exercise meals may consist of whole foods, liquid nutrition supplements, bars or smoothies. If whole foods are preferred over supplements, individuals need to be aware of the quantities required to meet the recommendations. Examples of foods that contain 25 to 30 grams of carbohydrates include one cup of juice or a large piece of fruit, one bagel or two slices of whole wheat bread, one cup of most cereals, one large baked potato, two cups of skin milk, one cup of rice, corn or squash, and two-thirds cup of dried beans. Some very active individuals may need double or triple these amounts to meet their post-exercise needs.
Some examples of foods that contain 20- 25 grams of protein include three eggs (six egg whites or three-quarter cup of egg substitute), two cups of skin milk, three cups of soy milk or yogurt, three-quarter cup of cottage cheese, three ounces of chicken, fish, pork, or beef, three ounces of cheese (not cream cheese), and six tablespoons of peanut butter. Milk is an adequate but not necessarily optimal protein-carbohydrate drink for exercise recovery. Chocolate milk has been in the news lately as a post-exercise drink, however, keep in mind that the carbohydrates in most chocolate milk comes from added sugar and high-fructose corn syrup.
If you are goal-oriented and want to get the most out of your exercise efforts, it’s important to include nutrition as a critical factor in recovery and regeneration. Utilize this information about nutrient timing and optimal recovery and talk to your local fitness coach to develop a plan to get the most out of your exercise program.
Resource: IDEA Fitness Journal