The influence of time-equated training programs on muscle hypertrophy, strength, and body composition

The purpose of this study was to determine if barbell circuit training (RTC) as a model for concurrent training is superior to high intensity interval (CTHI) or moderate intensity continuous (CTMI) cycling for changes in muscular strength, hypertrophy, and body composition. Eleven trained males were recruited and counterbalanced into three groups. Each program featured three alternating days of resistance training per week, with one of the above time-equated (30-minute) concurrent training modalities between sessions. All groups increased muscular strength (p<0.05, RTC=7.48%, CTHI=10.32%, CTMI=15.74%) with no group differences (p>0.05). Increases in upper body muscle hypertrophy were similar in RTC and CTMI (p<0.01, RTC=20.18%, CTMI=20.97%), increases in lower body muscle hypertrophy only occurred in CTMI (VM: p=0.01, 38.59%, VLP: p=0.07, 13.33%), while no hypertrophy changes were detected in CTHI (p>0.05), no group experienced changes in body composition (p>0.05). These findings suggest similar muscle performance benefits from barbell circuit or cycling concurrent training.