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More research on BCAAs and protein

Exciting research continues to be published about the benefits of increasing protein. In particular, emerging research indicates that the branched chain amino acids (BCAAs) confer specific health effects.

BCAAs are unique because they are preferentially burned as energy by muscles to fuel work. Therefore, exercise causes an increased need to supply these amino acids in the diet. Whey protein is a very rich source of BCAAs. Studies have shown this is important for serious athletes, general fitness enthusiasts, or those who just want to shed a few pounds. Here is a sampling of some recent papers demonstrating the value of upping your BCAA intake.

BCAAs protect against muscle damage and strength loss during intense resistance training 

In a study just published, my laboratory group investigated the effects of supplementing with an amino acid formula rich in BCAAs on strength and muscle damage during a short-term period of very high-intensity, high-volume resistance training.1

Resistance-trained men were randomly assigned to either a BCAA group or a placebo group. They underwent 4 weeks of intense resistance training designed to induce a state of overtraining. The protocol consisted of total body workouts performed 5 days a week for 4 weeks. Muscle strength was tested each week.

The intense training resulted in a significant decline in strength in the placebo group, but BCAA supplementation prevented a performance decline in the other group. The group taking BCAAs also had higher testosterone levels and lower markers of muscle damage. The findings indicate that BCAA supplementation can prevent muscle strength loss during initial high-volume resistance training work, possibly by reducing muscle damage and maintaining an anabolic (muscle building) environment.

Proteins rich in BCAAs stimulate protein synthesis in older individuals 

This study involved older men and women aged 65-79 years of age.2 They were provided 15 grams of whey protein or an equivalent amount of an essential amino acid formula rich in BCAAs, each totaling 60 calories. Measures of protein synthesis were made for 3 hours after ingestion of the meals. It was found that both sources of amino acids significantly increased protein synthesis in leg muscles.

There was, however, a better effect with the BCAA-rich formula compared to whey, probably because whey contains some of the non-essential amino acids. The important point is that small amounts of whey protein or essential amino acids equal to just 60 calories elicit significant increases in muscle protein synthesis.

Whey protein stimulates glycogen levels

Glycogen is the storage form of carbohydrate in the body. Adequate levels of glycogen help to sustain high levels of exercise. A recent report found that whey protein increased glycogen levels in both the liver and skeletal muscle of exercise-trained rats more so than other types of protein.3 Whey may increase glycogen by promoting glucose uptake into cells and enhance the machinery in cells that lead to the formation of glycogen. Maintaining adequate glycogen day to day can be difficult, especially if you are training intensely. Increasing whey can help and may be one method to help keep glycogen levels elevated for those restricting carbohydrates.

BCAAs taken before resistance exercise reduces muscle soreness

Japanese researchers conducted a study that investigated whether supplementing with BCAAs could reduce muscle soreness after intense exercise.Healthy men and women performed a series of squat exercises (7 sets of 20 squats per set) 15 minutes after consuming a BCAA solution or an identical-tasting placebo. The BCAA solution contains 5 grams total of leucine, isoleucine, and valine. Muscle soreness and fatigue was assessed before and after exercise and for 4 days post-exercise. In the placebo group, muscle soreness peaked about 2-3 days after exercise and muscle fatigue peaked immediately after exercise. Soreness and fatigue also occurred in the BCAA group, but the magnitude was significantly reduced.

The results show that 5 grams of BCAAs consumed before resistance exercise reduces muscle soreness and muscle fatigue for several days after exercise, supporting the use of BCAAs in enhancing recovery. The same result would be expected taking about 20-25 grams of whey protein, which contains about 5 grams BCAAs.

Diets higher in protein and lower in carbs enhance body composition

Diets that promote either restriction in dietary carbohydrate or higher protein intake are very popular, however official agencies are reluctant to promote them because they conflict with current recommendations that focus on lowering total fat. Proponents of high protein diets claim these diets enhance body composition compared to traditional diets by either enhancing fat loss or augmenting muscle gain or both. A comprehensive review that examined a total of 86 scientific studies on the effects of dietary carbohydrate and protein on weight loss and body composition was recently conducted.5

The results from these studies were statistically analyzed using a meta-regression procedure that allows them to control for such confounding variables as age, gender, caloric intake, etc. The results clearly showed that diets higher in protein were associated with greater retention of lean body mass, and this effect was also independent of caloric intake. Overall, the results of this extensive review provide convincing evidence that increasing protein and lowering carbohydrate intake can have a significant benefit on body composition.

Summary

These studies provide additional evidence for diets higher in protein, particularly whey protein, BCAAs or other sources of BCAAs, as part of an overall healthy lifestyle.

 

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