ATLAS study: Design, athletic performance, and sex-specific regression models for muscle strength in the Greek population.

PURPOSE: ATLAS is a cross-sectional study aiming to investigate environmental and genetic determinants of athletic performance in healthy Greek competitive athletes (CA). This article presents the study design, investigates the muscle strength performance (MSP) of 289 adult and teenage CA, exercisers, and physically inactive individuals (PI), and proposes predictive models of MSP for adults.

METHODS

Muscle maximal, speed, and explosive strength (MMS/MSS/MES) at unilateral maximal concentric flexion and extension contraction (FC/EC) were evaluated using Biodex System 3 PRO™ at 60 °/s, 180 °/s, and 300 °/s, while additional performance markers were assessed through field ergometric testing. Participants were interviewed about their lifestyle, dietary habits, physical activity, injury, and medical history. Body composition was assessed via bioelectrical impedance. gDNA was extracted from biochemical samples and then genotyped. Statistical analysis was conducted using IBM SPSS Statistics v21.0 and R.

RESULTS

Age, fitness, and sex impacted correlations of MSP with body composition and anthropometric measurements (p ​< ​0.05). Among CA, females outperformed males in accuracy (p ​< ​0.001) while, males outperformed females in anaerobic power, MSP, speed, and endurance (p ​< ​0.001). Adult CA outperformed exercisers and PI in MMS, MSS, and MES (p ​< ​0.05). Multiple linear regression models, with predictors age, FFM, body extremity, training load explained the majority of variation in MMS (R 2 adj:71.4%-88.9%), MSS (R 2 adj:64.8%-78.4 ​%), and MES (R 2 adj:52.7%-68.4 ​%) at EC, FC, and their mean (p ​< ​0.001).

CONCLUSIONS

Muscle-strengthening strategies should be customized according to individual fitness levels, body composition, and anthropometric measurements. The innovative sex-specific regression models assessing MMS, MSS, and MES at EC and FC provide a framework for personalizing rehabilitation and skill-specific training strategies.