Study under review: A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance traininginduced gains in muscle mass and strength in healthy adults
Resistance training is a type of exercise characterized by skeletal muscles (the muscles responsible for voluntary movement) being forced to contract against some form of external load. This unique type of exercise has important health benefits that are mediated, in part, through its ability to increase muscle mass and strength. Not only does skeletal muscle help you look good naked, but it plays an important role in the prevention of many diseases such as obesity, type 2 diabetes, and osteoporosis.
Protein supplementation is a widespread practice among people who partake in resistance training, be they athletes or average. The idea is that protein supplementation will enhance training-induced gains in muscle mass and strength. Although a single exercise session increases muscle protein synthesis for up to 48 hours, overall muscle protein balance is negative without nutritional intervention. Consuming protein after training has been shown to shift muscle protein balance from a negative to a positive state.
Several meta-analyses and systematic reviews have reported that protein supplementation leads to increased muscle mass and strength. The largest meta-analysis to date was conducted in 2012 and included 22 randomized controlled trials. It reported that protein supplementation significantly enhanced muscle mass and strength in both young and older adults. However, a recent systematic review has challenged this conclusion, arguing that the effect of protein supplementation on muscle mass and strength is inconsistent and any benefit is minor, at best. This review was not a meta-analysis though, meaning that there are about five years of data that have not been evaluated quantitatively.
The study under review is a meta-analysis investigating the impact of protein supplementation on several important resistance training outcomes, including muscle mass and strength. It contains more than double the number of studies included in the previous meta-analysis from 2012, including studies published in the last five years that the other meta-analysis did not include.
Skeletal muscle plays an important role in health and resistance training, the go-to method for increased muscle mass and strength. The benefit of protein supplementation for enhancing resistance training-induced adaptations, while supported previously, has recently been questioned. The study under review is an updated meta-analysis investigating the effect of protein supplementation on muscle mass and strength.
Other Articles in Issue #34 (August 2017)
Interview: Brandon Roberts, PhD
In this volume, exercise scientist, coach, and research consultant Brandon Roberts talks with us about common mistakes he sees in strength training, the state of exercise science, and more.
Interview: Phil Graham, BSc, PGDip, CISSN, MSc(c)
Phil Graham lives and thrives with type 1 diabetes. In this interview, we pick his brain about his body building experience, tips for professionals working with athletes with type 1 diabetes, and the interactions between insulin, dietary protein, and muscle protein synthesis.
Beef protein: anabolic underdog?
Whey protein supplementation is considered a top contender when in comes to improving resistance training outcomes. Can a protein supplement derived from beef compete?
Lean beef: take it or leave it for weight loss
High-protein diets are one way to shed some pounds. Is red meat any better or worse of a protein source for those looking to lose weight?
Is there really no benefit from protein supplementation on weight loss maintenance?
There’s reason to think that protein supplementation can be helpful for weight loss. The question of whether it’s useful in weight maintenance is another matter
Ginger, vitamin B6 , or neither for nausea during pregnancy?
Ginger and vitamin B6 are commonly thought to be helpful for nausea and vomiting during pregnancy. Few trials have looked at them head-to-head, though.
Can supplemental vitamin D improve sleep?
Vitamin D levels seem to be correlated with sleep quality. But correlation doesn’t necessarily equal causation