The Effects of Greek Yogurt and Exercise on Strength, Muscle Thickness and Body Composition in Untrained, University-Aged Males

Abstract

Previous research has shown the effectiveness of milk/whey protein plus exercise on increasing muscle size, optimizing body composition and increasing strength in adult males and females. Greek yogurt (GY) contains similar muscle-supporting nutrients as milk yet it is different in several ways including being a solid food, and it has yet to be investigated in this context. Thus, the purpose of this study was to assess the effects of GY consumption plus exercise (resistance and plyometric) training on strength, muscle thickness and body composition. Thirty untrained, university-aged (18-25 years) males were randomized to 2 groups (fat-free, plain GY; n= 15, or a Placebo Pudding [PP; isoenergetic carbohydrate-based pudding]; n= 15) and underwent a combined resistance/plyometric training program 3d/week for 12 weeks. They consumed either GY (20 g protein per serving) or PP (0 g protein per serving) daily (GY: 3x200 g on training days and 2x150 g on non-training days; spread throughout the day). After 12 weeks, both groups significantly increased strength, muscle thickness and fat-free mass from baseline (p<0.05). GY gained more strength (GY; 26.8%, PP; 15.1%) than PP in 3 of 4 exercises determined by 1-RM (p<0.05). GY gained more biceps brachii muscular thickness (GY; 16.4%, PP; 7.1%) than PP determined by ultrasound (p<0.05). GY also increased fat-free mass (GY; 3.9%, PP; 2.3%) and reduced % body fat (GY; -1.1%, PP; 0.1%) more than PP determined by air-displacement plethysmography (p<0.05). Thus, consumption of GY during a training program resulted in improved strength, muscle thickness and body composition over a carbohydrate-based placebo. Given the benefits of consuming GY and its distinctiveness from milk, GY may offer a plausible, post-exercise, nutrient-rich alternative for positive strength, muscle and body composition adaptations.