Effects of Split Versus Full-Body Resistance Training on Strength Gains and Macronutrient Intake in Trained Men Over a Six-Week Mesocycle

The purpose of this study was to gain a deeper understanding of the potential effects of a six-week mesocycle on strength improvements in trained men. Twenty-four resistance-trained males (with over ۴ years of experience and at least ۶ months of consistent resistance training), aged above ۲۳ years (mean age ۲۸.۲۵ ± ۲.۵۵ years), were randomly selected for participation. The average height was ۱۷۹.۰۴ ± ۴.۵۲ cm, and the pre-training weight was ۸۰.۶۳ ± ۶.۹۷ kg, with a BMI of ۲۵.۱۴ ± ۱.۷۸.Participants were randomly assigned to one of two groups (n=۱۲ each): the split routine group (pre-weight ۸۰.۴۰ ± ۸.۰۳ kg; height ۱۸۰.۲۵ ± ۵.۲۲ cm; BMI ۲۴.۷۰ ± ۱.۷۲; age ۲۶.۸۳ ± ۳.۰۶ years) and the full-body group (pre-weight ۸۰.۸۶ ± ۶.۰۸ kg; height ۱۷۷.۸۳ ± ۳.۵۱ cm; BMI ۲۵.۵۷ ± ۱.۸۰; age ۲۹.۶۶ ± ۳.۵۵ years). The split group engaged in workouts characterized by lower total volume per session, lower intensity, and more single-joint movements. In contrast, the full-body group performed workouts with higher total volume per session, higher intensity, and primarily multi-joint movements.Both groups underwent a six-week training protocol consisting of three resistance training sessions per week, totaling ۱۸ sessions. Each session included ۳ sets of ۸–۱۰ repetitions per exercise, with a progressive step-up in intensity (۰–۵% increase each week, followed by one week of adaptation), starting from approximately ۸۰% of their pre-test one-repetition maximum (۱-RM). Statistical significance was set at α = p ≤ ۰.۰۵.Maximal strength was assessed using the barbell chest press and barbell squat exercises. Due to non-normal data distribution, the Mann-Whitney U test and Wilcoxon signed-rank test were employed for intra-group comparisons and pre-post differences. The Mann-Whitney U test revealed no significant differences between the two groups in ۱-RM chest press pre-test (P = ۰.۵۶۳) and post-test (P = ۰.۳۲۶), or in ۱-RM squat pre-test (P = ۰.۵۸۲) and post-test (P = ۰.۹۰۸). The Wilcoxon test indicated significant improvements within both groups (P = ۰.۰۰۰), with an effect size of ۰.۸۸.Mean results demonstrated that the full-body group increased their chest press ۱-RM by ۱۶.۷۴% and squat ۱-RM by ۱۰.۰۸%, while the split group showed increases of ۱۴.۹۷% and ۸.۳۱%, respectively. Caloric intake increased by ۶.۴۳% in the full-body group and ۴.۳۸% in the split group. Protein intake rose by ۱۳.۵۹% (full-body) and ۱۲.۰۲% (split), carbohydrate intake increased by ۷.۱۷% and ۵.۷۶%, and fat intake decreased by ۷.۰۸% and ۷.۹۸%, respectively. Body weight remained virtually unchanged, with a ۰% change in the full-body group and a ۰.۱۷% decrease in the split group.In conclusion, both training systems effectively enhanced maximal strength over the six-week mesocycle in trained individuals, with no significant differences observed between the split and full-body routines. Additionally, participants in both groups exhibited increased caloric intake and shifts in macronutrient consumption toward higher protein and carbohydrate intake and reduced fat intake, while maintaining stable body weight. These findings suggest that while both training modalities are effective for strength gains in the short term, they may also influence dietary intake and macronutrient preferences.

کلیدواژه ها:

Resistance training ، periodization ، body composition ، strength and conditioning ، performance