Effects of Resistance Training Overload Progression Protocols on Strength and Muscle Mass.
Level 2 - randomized trial
Individual within-subject randomized controlled trial
PubMed 38286426 · doi:10.1055/a-2256-5857
What was done
Thirty-nine previously untrained young adults (20 men, 19 women) completed a 10-week resistance training intervention using a within-subject design. Each participant had one leg randomized to progressive load increases (LOADprog) and the other leg to progressive repetition increases (REPSprog) during leg extension training. Quadriceps muscle strength was assessed via 1-repetition maximum (1RM) leg extension, and vastus lateralis cross-sectional area (CSA) was measured via ultrasound before and after the 10-week protocol.
What was found
Both protocols increased 1RM strength from pre to post (LOADprog: 52.90 ± 16.32 kg to 69.05 ± 18.55 kg; REPSprog: 51.67 ± 15.84 kg to 66.82 ± 17.95 kg) with no statistically significant difference between protocols (p > 0.05). Both protocols also increased vastus lateralis CSA from pre to post (LOADprog: 21.34 ± 4.71 cm² to 23.53 ± 5.41 cm²; REPSprog: 21.08 ± 4.62 cm² to 23.39 ± 5.19 cm²), also without significant differences between protocols (p > 0.05).
Why it matters
These findings suggest that in the early phases of resistance training, progressive overload can be effectively achieved either by adding load or by adding repetitions to yield comparable hypertrophy and strength adaptations.
Limits
The sample was restricted to untrained young adults over a short duration (10 weeks) performing a single isolation exercise (leg extension). Findings may not generalize to trained individuals, compound multi-joint movements, other muscle groups, or long-term training adaptations, and within-subject unilateral designs carry potential systemic or cross-education crossover effects.
Cited by
- supports Scientific evidence indicates that simply having a structured workout plan that enables progressive overload matters more for results than the specific details of the plan itself.