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

ABSTRACT: Øfsteng, SF, Hammarström, D, Knox, S, Jøsok, Ø, Helkala, K, Koll, L, Hanestadhaugen, M, Raastad, T, Rønnestad, BR, and Ellefsen, S. Superiority of high-load vs. low-load resistance training in military cadets. J Strength Cond Res 38(9): 1584-1595, 2024-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.

No effect of increasing protein intake during military exercise with severe energy deficit on body composition and performance.

In this study, we compare the effects of isocaloric high- (HIGH: 2 g kg-1  d-1 , n = 19) and low-protein diet (LOW: 1 g kg-1  d-1 , n = 19) on changes in body composition, muscle strength, and endocrine variables in response to a 10-day military field exercise with energy deficit, followed by 7 days of recovery. Body composition (DXA), one repetition maximum (1RM) bench and leg press, counter-movement jump height (CMJ) and blood variables were assessed before and after the exercise. Performance and blood variables were reassessed after 7 days of recovery. The 10-day exercise resulted in severe energy deficit in both LOW and HIGH (-4373 ± 1250, -4271 ± 1075 kcal d-1 ) and led to decreased body mass (-6.1%, -5.2%), fat mass (-40.5%, -33.4%), 1RM bench press (-9.5%, -9.7%), 1RM leg press (-7.8%, -8.3%), and CMJ (-14.7%, -14.6%), with no differences between groups. No change was seen for fat-free mass. In both groups, the exercise led to a switch toward a catabolic physiological milieu, evident as reduced levels of anabolic hormones (testosterone, IGF-1) and increased levels of cortisol (more pronounced in HIGH, P < .05). Both groups also displayed substantial increases in creatine kinase. After 7 days of recovery, most variables had returned to close-to pre-exercise levels, except for CMJ, which remained at reduced levels. In conclusion, increased protein intake during 10-day military field exercise with severe energy deficiency did not mitigate loss of body mass or impairment of physical performance.