Optimal timing to assess exercise-induced oxidative stress: A systematic review and meta-analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized and non-randomized studies
PubMed 41318971 · doi:10.1113/EP092963
What was done
Systematic review and meta-analysis (PROSPERO CRD42024508049) of 103 studies (n = 1418) to determine optimal post-exercise assessment timing for three redox biomarkers: glutathione, F2-isoprostanes, and protein carbonyls. Standardised mean differences (SMD) were calculated using random-effects models with 95% confidence and prediction intervals. Study quality was evaluated using RoB2, ROBINS-I, Egger's test, funnel plots, and GRADE certainty rating.
What was found
Glutathione decreased immediately (Hedges' g = -0.70; 95% CI: -0.96, -0.44; P < 0.001), at 30 min to 2 h (g = -0.81; 95% CI: -1.19, -0.43; P < 0.001), and at 48 h (g = -0.98; 95% CI: -1.50, -0.46; P < 0.01). F2-isoprostanes increased immediately (g = 1.01; 95% CI: 0.70, 1.33; P < 0.001) and at 30 min to 2 h (g = 0.46; 95% CI: 0.23, 0.69; P < 0.001). Protein carbonyls were elevated at all time points, especially at 48 h (g = 1.17; 95% CI: 0.73, 1.60; P < 0.001) and peaked at 72 h (g = 1.33; 95% CI: 0.52, 2.14; P = 0.0048). Non-muscle-damaging exercise elicited responses within 2 h, whereas muscle-damaging exercise produced delayed peaks at 48 to 72 h.
Why it matters
This review establishes empirical time windows for redox biomarker sampling after exercise, showing that timing must be tailored specifically to whether the exercise protocol induces muscle damage.
Limits
Egger's test indicated significant publication bias for F2-isoprostanes (P = 0.017) and protein carbonyls (P = 0.031). Risk of bias was moderate in randomized controlled trials and serious in non-randomized studies. The analysis was limited to only three specific redox biomarkers.
Cited by
- context Exercise does not reduce oxidative stress and actually makes oxidative stress worse.