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Protein supplements are invading grocery store aisles and health food stores promising greater strength, faster recovery time and bigger muscles. Is a supplement what athletes need or can they get by with just a glass of milk? The answer lies within the glass. When athletes eat, and what ratio of carbohydrates to proteins they eat after a workout can significantly improve the recovery period after exercise (4).Post-Workout RecommendationsTiming is everything, especially when it comes to what athletes eat after engaging in strength and conditioning training. Eating a combination of carbohydrates and protein within 30 mins post-workout helps maximize muscle synthesis, muscle function and decreases muscle breakdown. This occurs because this is the time that muscles experience a heightened sensitivity to insulin (4,7). Additionally, consuming the right combination of carbohydrates to protein, in a 4:1 ratio, is associated with faster glycogen replenishment in the muscles, better muscle protein synthesis, reduced muscle soreness and improved muscle strength and body composition (2,4). Thus, the recipe for optimal post-exercise recovery is taking advantage of the 30 min recovery window and choosing foods that portray the 4:1 ratio of carbohydrates to protein. Chocolate milk is a quick and easy post-recovery drink that naturally contains carbohydrates and proteins in the correct ratio. See Table 1 for other post-exercise snack options.Whey vs. CaseinCow’s milk is composed of carbohydrates and two main dairy proteins: casein and whey. When milk is coagulated, it automatically divides out the proteins into semi-solid lumps and a liquid portion. Casein is found in the lumps, or curds, whereas the whey protein is found in the liquid portion (5). The ratio of protein within a glass of milk is about 20% whey to 80% casein, which provides an optimal composition of readily available nutrients to replenish body fuel post-workout and keep energy levels up (5).Whey is known as the “fast-acting” protein, meaning that the body can break it down and absorb the nutrients relatively quickly (1). In some cases, manufacturers break down whey even further into whey protein isolate, whey concentrate or whey powder, which are then sold in different forms as supplements. These lactose-free, concentrated protein supplements are absorbed at a quicker rate than casein. Additionally, whey is high in indispensible (essential), branched-chain amino acids that the body cannot produce on its own and must derive from food (1).
This allows for quick uptake by the body (6). Some studies have found that whey protein supplements may be associated with an increase in muscle mass size and strength in some individuals as well (7). Casein, often referred to as the “slow-acting” protein, takes slightly longer to digest as it slowly releases amino acids into the bloodstream (6). It contains a different amino acid profile than whey and is particularly high in the conditionally indispensible amino acid, glutamine (1). This is beneficial because, when the body is put under physiological stress, such as with endurance exercise, the body needs to derive glutamine from an outside source of food (1). The bottom line, however, is that both whey and casein are needed for proper nutrition. Some supplements contain both whey and casein to allow the body to take full advantage of the different absorption rates (1,8). Additionally, the combined efforts are beneficial because whey works to stimulate protein synthesis whereas casein inhibits the breakdown of protein (9). Therefore, individual, isolated supplements of either whey or casein may not be the best option. Milk: Full or Low-Fat? Research shows that low-fat dairy is more effective at protein synthesis and replenishing net muscle protein balance than high-fat dairy (6). One theory is that the fat is digested at a slower rate than carbohydrates and protein, and thus the fat slows down the delivery of carbohydrates and protein to tissues (6). Furthermore, chronic use of low-fat milk as a post-exercise resistance training meal has been associated with a greater reduction in overall body fat, increased muscle growth and greater muscle mass maintenance than soy-based proteins (3,9). Table 1 lists whole-food examples of post-exercise snack options that provide the optimal balance of carbohydrates to proteins. Eat these snacks within 30mins after completing an exercise session for optimal glycogen and protein uptake.
Table 1. Carbohydrate and Protein Content of Post-Exercise Snack Options (10).
Bottom LineThe combination of whey and casein protein found in cow’s milk provides reliable nutrition to restock glycogen stores, promote protein synthesis and repair muscles while providing beneficial nutrients such as calcium, vitamin D and vitamin A (6). Whole foods, such as low-fat milk, can be equally effective, if not more effective than supplement drinks in restoring the body to optimal performance levels and naturally provide all the essential nutrients in a ratio the body needs (6). Choose whole foods that contain a 4:1 ratio of carbohydrates to protein and consume them within 30mins after exercise to support muscle recovery, strength and build muscle mass.
Debra Wein is a recognized expert on health and wellness and has designed award-winning programs for both individuals and corporations around the United States. She is president and founder of Wellness Workdays, Inc., (www.wellnessworkdays.com) a leading provider of worksite wellness programs. In addition, Wein is the president and founder of partner company, Sensible Nutrition, Inc. (www.sensiblenutrition.com), a consulting firm of RD’s and personal trainers, established in 1994, that provides nutrition and wellness services to individuals. Wein has nearly 20 years of experience working in the health and wellness industry. Megan Miraglia is a registered dietitian at Wellness Workdays and Sensible Nutrition, Inc. where she conducts nutrition and wellness seminars, classes and one-on-one counseling with clients. Previous to Wellness Workdays, she worked in research focused on the prevention of childhood obesity. She completed a dietetic internship at Frances Stern Nutrition Center and earned a Master’s degree at Tufts University.
There is much information on rbst treated cows these days. Also high levels of arsenic, cadmium, lead, and mercury in many protein powders.. Choose your post-workout supplementation/nutrition wisely my friends.