# Effect of a 6-Week Structured Exercise Intervention on TNF-α During the Chronic Recovery Phase of a Burn Injury Compared to Regular Daily Activities: A Pilot Randomised Cross-Over Trial

## TL;DR

A 6-week exercise program improved muscle strength and fitness in burn survivors but did not affect TNF-α levels during chronic recovery.

## Contribution

This study is the first to investigate the effect of structured exercise on TNF-α in non-severe burn survivors during chronic recovery.

## Key findings

- Exercise significantly improved quadriceps strength and cardiovascular fitness in participants.
- TNF-α concentrations were not elevated at baseline and showed no significant change after the exercise intervention.
- The intervention was found to be safe and effective for non-severely burned patients.

## Abstract

Background: Burn injury induces a prolonged inflammatory response that may contribute to long-term metabolic dysfunction. Exercise is known to reduce inflammation in various clinical populations; however, its effect on chronic post-burn inflammation remains unclear. This crossover trial investigated the impact of a 6-week exercise intervention on tumour necrosis factor-alpha (TNF-α) in adults with non-severe burns sustained more than one year prior. Methods: Twenty-one participants were randomised to complete either a 6-week exercise program or a control period first, separated by a 4-week washout. The exercise program comprised three supervised sessions per week of combined resistance and cardiovascular training. Primary (TNF-α) and secondary (muscle strength, cardiovascular fitness) outcomes were assessed pre- and post-intervention. Results: Fifteen participants completed the protocol with high adherence (90.4%). Exercise significantly improved quadriceps strength and cardiovascular fitness, confirming the intervention’s safety and efficacy in this cohort. However, TNF-α concentrations were not elevated at baseline and did not significantly change following exercise compared with control (mean difference: +0.5 pg·mL−1, p = 0.249). Exercise is safe and beneficial for non-severely burned patients who sustained their injury > 1 year ago. However, inflammation was not elevated in this cohort, precluding our ability to test the effects of exercise on chronic inflammation.