Timing matters? The effects of two different timing of high protein diets on body composition, muscular performance, and biochemical markers in resistance-trained males

Background It is unclear whether resistance training in combination with different timing of protein intake might have differential effects on muscle hypertrophy, strength, and performance. Therefore, we compared the effects of 8 weeks of resistance training combined with two different high-protein diet strategies (immediately pre-and after, or 3 h pre and after exercise) in resistance-trained males. Methods Forty resistance-trained males (24 ± 4 years) performed 8 weeks of resistance training combined with 2 g kg −1 d −1 protein. Body composition, muscular performance, and biochemical markers were assessed pre and post-intervention. Results Nine participants (four from 3 h group and five from the immediate group) withdrew from the study. Therefore, 31 participants completed the study. All measures of skeletal muscle mass, Australian pull-up, and muscle strength, significantly increased post-intervention in both groups ( p < 0.05). The biochemical marker urea also significantly increased from pre to post in both groups ( p < 0.05). There were no significant between-group differences ( p > 0.05). Conclusion High-protein diet enhances muscular performance and skeletal muscle mass in resistance-trained males, irrespective of intake time. Consequently, the total daily protein intake appears to be the primary factor in facilitating muscle growth induced by exercise.