Athletes and active people can benefit from supplementing with protein after their workouts. According to a study published in the "American Journal of Clinical Nutrition," protein helps transport amino acids into the muscle after an intense workout. While you may be able to meet all your protein needs by eating whole foods such as meat or eggs, you can also supplement with powders, shakes or bars.
How Much Protein
The American College of Sports Medicine recommends that people who engage in endurance or strength training ingest 0.5 to 0.75 of protein per pound of body weight per day. As part of that amount, a study published in the "American Journal of Clinical Nutrition" found ingesting 20 grams of intact protein after resistance or endurance training is sufficient to maximize muscle repair and growth. The study further found that when you consume more than the recommended 20 grams post-workout, the body uses the excess protein for energy and excretes the surplus amino acids in your urine.
What Type of Protein
Whey protein, a natural byproduct of the cheese-making process, is often the preferred protein used post-exercise. Whey digests quicker than other proteins, including slow-digesting casein, which allows it to shuttle amino acids faster to the working muscles. Whey protein is available in powder forms and as part of nutrition shakes and bars. Some supplements include a combination of whey and casein protein to ensure that muscles receive both immediate and slower, ongoing amino acids. Vegetarians and those who are lactose intolerant can supplement with soy or soy protein powder; however, this has been shown to be less effective than supplementing with milk-based proteins, according to the "Journal of Sports Science and Medicine."
Protein to Carbohydrate Ratio
After a hard workout, your body also needs fluids, electrolytes, energy, and carbohydrates to replace muscle glycogen. The American College of Sports Medicine recommends a carbohydrate intake of approximately 0.5 to 0.7 grams per pound of body weight during the first 30 minutes post exercise and again every two hours for the next four to six hours to replace glycogen stores. A study in the "Journal of Sports Science and Medicine" recommends a 3-to-1 ratio of carbohydrates to protein post-exercise.
When to Take Protein
Fitness experts suggest taking your protein within an hour of finishing your workout. While a study published in the Journal of Applied Physiology in 2000 suggested that there is no difference in benefits between digesting protein one and three hours after training, more recent studies have challenged this finding. Studies in the "American Journal of Physiology – Endocrinology and Metabolism" indicated that supplementing with protein immediately after your workout provides a better anabolic or muscle-building response than if you digest the protein two or three hours after your workout.
- Medicine & Science in Sports & Exercise: Nutrition and Athletic Performance: Joint Position Statement; American College of Sports Medicine, American Dietetic Association and Dietitians of Canada; March, 2009
- Journal of the International Society of Sports Nutrition: Contemporary Issues in Protein Requirements and Consumption for Resistance Trained Athletes; Jacob Wilson et al.
- Journal of Sports Science and Medicine: The Role of Post-Exercise Nutrient Administration on Muscle Protein …; Chris Poole, et. al.
Andrea Chrysanthou began writing professionally in 1993. Her work has been published internationally by "The Cyprus Mail," MochaSofa and My Favorite Trainer, among other magazines and websites. She holds a Bachelor of Applied Arts in journalism from Ryerson University. Chrysanthou is a certified fitness instructor and personal-training specialist with more than 10 years of experience in the fitness industry.