# Neuromuscular Profile of CrossFit® Athletes: Part 1—Isometric and Ballistic Performance

## TL;DR

This study compares the neuromuscular performance of male and female CrossFit athletes, finding that differences are mainly due to absolute strength rather than neuromuscular efficiency.

## Contribution

The study provides novel descriptive neuromuscular data for CrossFit athletes and identifies sex-based differences in absolute force production.

## Key findings

- Males showed higher absolute and relative isometric force outputs compared to females.
- No significant sex differences were found in time to peak force or dynamic strength index.
- Ballistic performance metrics like jump height and momentum were higher in males but normalized values showed comparable relative function.

## Abstract

Background: CrossFit® has gained widespread popularity as a high-intensity training modality, yet evidence describing neuromuscular performance characteristics in this population remains limited. This study aimed to evaluate isometric and ballistic strength profiles in trained CrossFit® athletes and to identify sex-based differences in absolute and relative neuromuscular performance. Methods: Seventy-two athletes participated (41 males and 31 females) participated in the study, completing two maximal isometric mid-thigh pull (IMTP) tests and three countermovement jump (CMJ) tests within a single testing session. Assessments were conducted using a dual force plate system (Hawkin Dynamics, Westbrook, ME, USA). Results: In the IMTP, males exhibited substantially higher absolute isometric force outputs, including peak force (3059 ± 576 vs. 1899 ± 324 N; p < 0.001) and relative peak force (36.34 ± 6.74 vs. 30.99 ± 4.41 N/kg; p < 0.001). Rates of force development were also greater in males for both early (0–50 ms: 7665 ± 5420 vs. 4001 ± 3021 N/s; p < 0.001) and late phases (0–250 ms: 5350 ± 1832 vs. 3035 ± 886 N/s; p < 0.001). However, no significant sex differences were detected in time to peak force (2.31 ± 1.27 vs. 1.94 ± 1.04 s) or dynamic strength index (0.72 ± 0.12 vs. 0.73 ± 0.12 a.u.). In ballistic performance using CMJ, males achieved higher jump height (0.33 ± 0.07 vs. 0.23 ± 0.05 m; p < 0.001), jump momentum (215 ± 27.9 vs. 131 ± 19.1 kg·m/s; p < 0.001), and modified reactive strength index (0.46 ± 0.11 vs. 0.32 ± 0.08 a.u.; p < 0.001). Relative propulsive and braking forces were also moderately greater in males. Notably, sex differences were reduced when variables were normalized to body mass or peak force, indicating comparable relative neuromuscular function across sexes. Conclusions: These findings provide descriptive neuromuscular performance data for CrossFit® athletes and show that sex-based differences primarily reflect disparities in absolute force-production capacity rather than intrinsic neuromuscular efficiency. Such insights may support more precise, evidence-informed, and sex-specific training prescriptions to optimize performance.