Effects of 12-week full body resistance exercise on vertical jumping with and without military equipment in Slovenian Armed Forces.

INTRODUCTION: Jumping ability is one of the most important physical qualities in military personnel. Previous training intervention studies have shown equivocal effects on jumping ability. In this study, we assessed the effect of a 12-week resistance exercise programme on countermovement jump (CMJ) performance with and without military equipment. METHODS: Ninety-six members of the Slovenian Armed Forces (age range 20-47 years) were allocated to the intervention (n=65) and the control (n=32) group. The intervention group performed 2 sessions of full body resistance exercise per week for 12 weeks, while the control group continued with their regular training routine. Before and after the intervention, CMJ assessment using force plates was conducted with and without military equipment. RESULTS: CMJ testing with and without equipment both exhibited high to excellent relative and absolute reliability. The intervention elicited statistically significant (p=0.011-0.026; η2=0.05-0.06), but small improvements in CMJ height when performed without equipment (from 28.2±3.8 cm to 29.5±3.3 cm) and with equipment (from 25.3±3.7 cm to 27.1±6.1). Other variables showed even smaller or trivial changes. CONCLUSIONS: This study suggests that CMJ with equipment could be a reliable tool to assess jumping performance specific to requirements of military work, which would increase the ecological validity of the testing. The present structured full-body training intervention showed modest improvements in jumping ability in both testing conditions. TRIAL REGISTRATION NUMBER: NCT0341546.

Regular strength training and baseline fitness in overweight infantry members of Slovenian Armed Forces.

INTRODUCTION: The prevalence of overweight subjects in military cohorts increases despite the obligatory army physical fitness test (APFT) requirements and the negative consequences of possible test failure due to the increased body mass index (BMI). Studies that have examined the association of BMI with baseline fitness in the military are showing conflicting evidence. The primary aim of the study is to examine BMI effects on baseline fitness that was measured by APFT and additional functional performance tests (FT) (vertical countermovement jump with and without load, loaded prone plank, single-leg hamstring bridge test and pull-ups). Our secondary goal is to explore if regular strength training modifies the BMI effect on baseline fitness. METHODS: A cross-sectional study on a sample of 118 male infantry soldiers that have performed APFT and FT was carried out. Body mass and body height measurements were used to calculate BMI, and to categorise participants into BMI ranks. Two independent categorical variables (BMI rank and strength training) were used to evaluate their influence on dependent variables of physical performance acquired from APFT and FT. RESULTS: A significantly large size effect of BMI rank (F=1.69, p=0.037; effect size (ES)=0.15) and regular strength training (F=2.66, p=0.006; ES=0.21) on physical performance was found. It was shown that strength training had a medium ES on push-up and pull-up performance, as well as on the overall APFT score and loaded plank. CONCLUSIONS: The importance of regular strength training and normal BMI for better overall baseline fitness in infantry members was highlighted. Most importantly, it was shown that performance is not affected in overweight soldiers who are performing regular strength training in addition to their daily physical training. TRIAL REGISTRATION NUMBER: NCT03415464.