# Are there reliable primary indicators of cardiorespiratory fitness in physically active students?

## TL;DR

This study explores whether handgrip strength and medical history interviews can reliably indicate cardiorespiratory fitness in active university students.

## Contribution

The study identifies handgrip strength and medical history interviews as potential surrogate markers for cardiorespiratory fitness.

## Key findings

- Handgrip strength showed the strongest association with cardiorespiratory fitness (R = 0.439).
- Combining handgrip strength and medical history interviews explained 49% of the variance in cardiorespiratory fitness.

## Abstract

Cardiorespiratory fitness is a central component of preventive sports medical assessments and plays a crucial role in early identification of health risk factors in asymptomatic populations as well as evaluating physical performance. Preventive examinations in sports medicine frequently include the assessment of Handgrip-Strength (HGS), International Physical Activity Questionnaire (IPAQ), or Medical History Interviews (MHI). The aim of this study is to investigate whether one of these can serve as a valid surrogate marker for cardiorespiratory fitness.

A total of 552 university students (mean age: 21.0 ± 3.79 years (37.5% male) underwent a standardized sports medical and motor performance assessment including Cardiopulmonary Exercise Testing (CPET) on a bicycle ergometer, IPAQ, HGS testing, and a structured MHI. Associations between VO2peak and the proposed surrogate markers were analysed, controlling for sex and body weight.

The parameters with the highest explanatory values were HGS (R = 0.439, p < .001) and MHI (R = 0.323, p < .001). The combination of these two parameters (HGS and MHI) had an explanatory value of R2 = 0.49 (F(3, 549) = 76.620, p < .001, n = 552).

Maximal HGS and MHI showed potential as first-level indicators of cardiovascular fitness and in combination they may support screening in settings with limited resources and can be used for risk group identification. However, for medical applications the Cardiopulmonary Exercise Testing remains indispensable for an accurate and comprehensive assessment of individual cardiovascular fitness.