Front-Loading Fatigue: Does the Pre-exhaustion Method influence Resistance Training-induced Muscular Adaptations?

This study aimed to compare the effects of pre-exhaust training and traditional training on muscular hypertrophy, strength, body composition, and muscular endurance in resistance-trained participants over an 8-week study period. We randomly assigned 48 young, resistance trained individuals (male = 32, female = 9; height = 173.0 ± 10.3 cm; weight = 81.7 ± 15.9 kg; age = 22.5 ± 4.1 yrs) to 1 of 2 experimental groups after initial testing: a pre-exhaust resistance training (RT) group (PreEx: n = 24) or a traditional RT group (TRAD: n = 24). The RT protocol consisted of the following lower body exercises: leg extension, Smith squat, seated hamstring curl, barbell Romanian deadlift. Participants in the TRAD group completed all sets for one exercise before performing a different exercise with ~2 minutes of rest between sets. The PreEx group performed a set of a single-joint exercise immediately prior (<10 seconds) to a set of the corresponding multi-joint exercise for that muscle group followed by ~2 minutes of rest. Both groups performed 4 sets of each exercise twice weekly with loads corresponding to 8-12 repetition maximum (RM). Assessments included pre-post measures of muscle thickness of the quadriceps and hamstrings, body composition, 1RM squat strength, local muscle endurance of the quadriceps, and the countermovement jump. Results showed slightly greater improvements in muscle size and body composition favoring TRAD, with statistical uncertainty for a true between-group difference. Changes in strength, local muscular endurance and countermovement jump height were similar between groups. In conclusion, TRAD would seem to be a better option than PreEx for those seeking to optimize muscle hypertrophy. Measures of strength, power and local muscular endurance were relatively similar between conditions, suggesting that PreEx is a viable alternative to TRAD for these outcomes.