Changes in physical fitness and anthropometrics differ between female and male recruits during the Finnish military service

Abstract

IntroductionMilitary training programmes are often similar for male and female recruits despite sex differences in physical performance that may influence training adaptations during military service. The present study aimed to compare changes in physical fitness and anthropometrics between Finnish female and male recruits during military service.MethodsA total of 234 690 male and 3549 female recruits participated in fitness tests at the beginning and end of military service between 2005 and 2015. Anthropometric measurements were body mass, height, body mass index (BMI) and waist circumference (WC). Fitness tests consisted 12 min running, standing long jump, and sit-ups and push-ups.ResultsNo changes were observed in anthropometrics, while both sexes improved most of the fitness test results. After adjustment for service time, branch, age, initial fitness test results, BMI and WC, improvement in running test performance was 158 m (95% CI 142 to 173, p≤0.001) greater in male than female recruits. Similarly, improvements were larger in male recruits for push-ups (5 reps/min, 95% CI 5 to 6, p≤0.001), sit-ups (2 reps/min, 95% CI 2 to 3, p≤0.001) and standing long jump (12 cm, 95% CI 11 to 13, p≤0.001) when compared with women.ConclusionsThe study revealed sex differences in adaptations to the standardised military training. Both male and female recruits improved their physical fitness, but smaller gains were observed in women using the same training programme. The mechanisms explaining sex differences in adaptations to military training, and whether tailored training programmes are needed specifically for female recruits to reduce sex differences during military service, warrants further studies.

Beyond change scores: Employing an improved statistical approach to analyze the impact of entry fitness on physical performance during British Army basic training in men and women

“…Of relevance, having a high initial fitness level is an important component for successful task performance during military service that functions to reduce the incidence of injuries or discharge. 23 Unlike many individual athletic pursuits, military training tends to be completed in groups with a range of different physical fitness attributes, with an end-goal of getting all members to meet minimum PES. To avoid detraining of the fittest recruits, streamed PT (i.e., individual training groups of recruits split by alike fitness) may provide greater exercise stimulus and subsequent physical adaptations for these recruits, 8 as fully individualized training programmes are not practically viable.…”

“…Importantly, for recruits of high fitness, these data suggest that the physical demands and progression experienced during BT may not be sufficient to elicit positive training responses, or they are already well trained that they have less capacity for improvement. Of relevance, having a high initial fitness level is an important component for successful task performance during military service that functions to reduce the incidence of injuries or discharge 23 . Unlike many individual athletic pursuits, military training tends to be completed in groups with a range of different physical fitness attributes, with an end‐goal of getting all members to meet minimum PES.…”

“…This was seen in Finnish recruits, where fitness test improvements were larger in men compared with women after 6-12 months of service, despite men commencing training with higher overall fitness levels. 23 Currently, women account for 10.9% of the British Army 24 and, have recently been permitted to serve in all job-roles irrespective of the associated physical demand. 25 Although male and female British Army recruits complete the same training programmes, women experience greater cardiovascular strain and increased injury risk during BT, which has been associated with their lower average body mass and aerobic fitness upon entry, relative to men.…”

“…However, a large gap in physical fitness between men and women still exists after BT, which may increase during further training and/or carryover into service. This was seen in Finnish recruits, where fitness test improvements were larger in men compared with women after 6–12 months of service, despite men commencing training with higher overall fitness levels 23 . Currently, women account for 10.9% of the British Army 24 and, have recently been permitted to serve in all job‐roles irrespective of the associated physical demand 25 .…”

Sex differences in the physical performance, physiological, and psycho‐cognitive responses to military operational stress

“…The greater preservation of lower‐body force in women compared with men (Yanovich et al, 2008) corresponds with the quicker recovery of CMJ height and lower body power in women than men following operational stress in the Vikmoen et al study (2020). In another study of sex‐integrated Israeli basic military training, women in the lowest tertile, but not men or women in the upper two tertiles, experienced a significant (28 %) improvement in cardiovascular fitness from pre‐ to post‐training, which suggests performance improvements may have been dependent on baseline fitness rather than sex (Nindl et al, 2012; Santtila, Pihlainen, Vaara, Tokola, & Kyröläinen, 2020). In a recent systematic review, Varley‐Campbell et al (2018) concluded that women experience greater absolute and relative improvements in aerobic fitness, strength, and muscular endurance compared with male recruits following basic military training, although greater physical performance improvements have been reported in men (Santtila et al, 2020).…”