Superiority of High-Load vs. Low-Load Resistance Training in Military Cadets

Abstract

Muscle strength and power are important determinants of soldiers' performance in modern warfare. Here, we compare the efficacy of 22 weeks of whole-body resistance training with high load (HL, 10 repetitions maximum/RM) and low load (LL, 30RM) for developing maximal muscle strength and power, performance, and muscle mass in moderately trained cadets (20 ± 1 year, f; n = 5, m; n = 22). Outcome measures were assessed at baseline and at week 22, in addition to a mid-intervention assessment at week 10. Twenty-two weeks of HL led to greater increases in muscle strength (upper limb, Δ 10%, 95% CI [2.8, 17.1], p = 0.01; lower limb, Δ 9.9%, CI [1.1, 18.6], p = 0.029), jump height (Δ 5.5%, CI [1.4, 9.6], p = 0.011), and upper limb lean mass (Δ 5.2%, CI [1, 9.4], p = 0.018) compared with LL. HL and LL led to similar changes in agility, muscle endurance performance, lower limb muscle mass, and cross-sectional area in m. vastus lateralis. For all variables, training-associated changes occurred primarily during the initial 10 weeks of the intervention, including the differential responses to HL and LL. In conclusion, although 22 weeks of HL led to greater increases in lower and upper limb muscle strength, power, and upper limb lean mass than LL, the 2 load conditions led to similar improvements in agility performance and lower limb muscle mass. Our results thus indicate that both loading regimes elicit multifaceted physiological improvements important for military readiness.