EFFECTS OF HIGH-VOLUME AND LOW-VOLUME RESISTANCE TRAINING ON MUSCLE HYPERTROPHY AND STRENGTH

Abstract

Background and Study Aim: Strength training is a fundamental aspect of physical performance and muscle hypertrophy. Strength gains largely depend on the volume of work done in training. The HVRT vs. LVRT debate rages on. The purpose of the current investigation was to compare the hypertrophic adaptations and effects of HVRT and LVRT on muscular strength-trained athletes, while addressing potential molecular mechanisms (i.e., mTOR signaling).

Material and Methods: A randomized controlled trial was conducted with 40 trained individuals (20 males, 20 females; age 20–30) randomly assigned to either an HVRT (5 sets per exercise) or LVRT (3 sets per exercise) group. Both groups underwent 8 weeks of resistance training, with three sessions per week. Muscle hypertrophy was determined by dual-energy X-ray absorptiometry (DXA), and strength gains were evaluated with one-repetition maximum (1RM) tests. Plasma mTOR signaling and myostatin levels were assayed.

Results: Both HVRT and LVRT groups had significant increases in muscle hypertrophy and strength (p < 0.05) with the HVRT group exhibiting larger changes in lean mass (4.2 ± 1.1 kg) increase compared to LVRT, as well as a greater magnitude of change on strength for squat (18.5 ± 4.3 kg), bench press (12.1 ± 3.8 kg) deadlift strength (14.3 ± 4.5). At molecular level, mTOR signaling was more activated and myostatin levels lower in HVRT than IHR group (p < 0.05).

Conclusion: HVRT is more effective than LVRT for muscle hypertrophy and strength in trained subjects. These early findings indicate that large training volumes are most effective in inducing muscular adaptations, likely via increased mTOR activity and decreased myostatin.