# Influence of Running Surface Differences on Physiological and Biomechanical Responses During Specific Sports Loading

## TL;DR

This study compares treadmill and overground running effects on body composition and knee stress in athletes.

## Contribution

It reveals how treadmill running alters protein and fluid levels and increases knee strain compared to overground running.

## Key findings

- Treadmill running significantly reduced protein content and increased intracellular fluid accumulation.
- Treadmill running decreased knee joint work by 27.4%, while overground running increased it by 5.6%.
- No significant changes in blood pressure were observed between treadmill and overground running.

## Abstract

The surface properties of the running surface have an effect on physiological and biomechanical responses to exercise, but their influence on body composition, blood pressure, and knee joint kinetics during controlled sports loading is less researched. This study compared the effects of treadmill running (TR) and overground running (OR) on acute physiological and biomechanical adaptation in ten male athletes aged between 23 and 26 years old following a 30 min protocol at 75% VO2max. Pre- and post-running body composition (fat volume, protein content, and fluid distribution), blood pressure, and knee joint kinetics (total work of muscle extensors—TWMEs) were assessed using bioelectrical impedance analysis, blood pressure monitor, and isokinetic dynamometry. The results indicated that TR led to highly significant reductions in protein content with a considerable accumulation of intracellular fluid. At the same time, TR reduced knee TWME by 27.4%, and OR elevated TWME by 5.6%. No significant differences in blood pressure were observed. These findings highlight surface-specific metabolic stress and biomechanical loading patterns and show that TR augments catabolic responses and knee joint strain despite equivalent external workloads.