# 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

## TL;DR

This study examines how initial physical fitness affects performance improvements in men and women during British Army basic training using a statistical approach.

## Contribution

The study introduces an improved statistical method to analyze physical performance changes, revealing gender-specific responses to training.

## Key findings

- Recruits with lower initial fitness showed greater improvements in physical performance during training.
- Men demonstrated greater improvements than women when matched for initial fitness levels.
- Training effectiveness is influenced by factors like age, maturity, and course duration.

## Abstract

The aim was to use a robust statistical approach to examine whether physical fitness at entry influences performance changes between men and women undertaking British Army basic training (BT). Performance of 2 km run, seated medicine ball throw (MBT) and isometric mid‐thigh pull (MTP) were assessed at entry and completion of Standard Entry (SE), Junior Entry‐Short (JE‐Short), and Junior Entry‐Long (JE‐Long) training for 2350 (272 women) recruits. Performance change was analyzed with entry performance as a covariate (ANCOVA), with an additional interaction term allowing different slopes for courses and genders (p < 0.05). Overall, BT courses saw average improvements in 2 km run performance (SE: −6.8% [−0.62 min], JE‐Short: −4.6% [−0.43 min], JE‐Long: −7.7% [−0.70 min]; all p < 0.001) and MBT (1.0–8.8% [0.04–0.34 m]; all p < 0.05) and MTP (4.5–26.9% [6.5–28.8 kg]; all p < 0.001). Regression models indicate an expected form of “regression to the mean” whereby test performance change was negatively associated with entry fitness in each course (those with low baseline fitness exhibit larger training improvements; all interaction effects: p < 0.001, ηp2 > 0.006), particularly for women. However, when matched for entry fitness, men displayed considerable improvements in all tests, relative to women. Training courses were effective in developing recruit physical fitness, whereby the level of improvement is, in large part, dependent on entry fitness. Factors including age, physical maturity, course length, and physical training, could also contribute to the variability in training response between genders and should be considered when analyzing and/or developing physical fitness in these cohorts for future success of military job‐task performance.