Effects of 16 weeks of two different high-protein diets with either resistance or concurrent training on body composition, muscular strength and performance, and markers of liver and kidney function in resistance-trained males

It is unclear whether resistance (RT) and concurrent training (CT; resistance plus endurance training) combined with different protein intakes have differential effects on muscle hypertrophy, strength, and performance. Therefore, we compared the effects of two high-protein diets (1.6 or 3.2 g.kg d ) during 16 weeks of either CT or RT alone in resistance-trained males. Forty-eight resistance-trained males (age: 26 ± 6 yr, body mass index: 25.6 ± 2.9 kg.m ) performed 16 weeks (four sessions·w ) of CT or RT with either 1.6 g.kg d protein (CT1; = 12; RT1; = 12) or 3.2 g.kg d protein (CT2; = 12; RT2; = 12). Training adaptations were assessed pre-, mid-, and post-intervention. All measures of performance (endurance, vertical jump, and pull-up), lean mass, muscle strength, and power significantly increased post-intervention in all groups, but peak power gains were greater in RT2 compared with RT1 and CT1 (