Improving the Assessment of Post-exercise Hypotension as a Predictor of Training Efficacy.

Post-exercise hypotension has been proposed as a promising biomarker for predicting the long-term blood pressure response to exercise training. This study assessed the reliability of post-exercise hypotension-from single- and averaged-session measurements-in 33 sedentary adults completing an 8-week aerobic exercise program. The resting blood pressure was measured before and after the intervention; acute post-exercise hypotension was defined as the change in blood pressure from pre-exercise to 10-minute post-exercise recovery and was measured across five separate sessions. Data were analysed using mixed-effects models. The impact of aggregating measurements on reliability and its correlation with chronic blood pressure reduction was assessed using analytical formulas and Monte Carlo resampling. The reliability of single-session post-exercise hypotension measurements was poor, with a high standard error of measurement (systolic blood pressure: 4.5 [4.0, 5.1] mm Hg and diastolic blood pressure: 4.3 [3.8, 4.9] mm Hg) and low intraclass correlation coefficients (systolic blood pressure: 0.24 [0.08, 0.29] mm Hg and diastolic blood pressure: 0.31 [0.13, 0.43] mm Hg). Reliability improved substantially when values were averaged across multiple sessions. The correlation between acute post-exercise hypotension and chronic blood pressure reduction also strengthened with averaging, albeit with diminishing returns. These findings support the potential of post-exercise hypotension as a predictive biomarker, particularly when averaged over several training sessions. The optimal number of sessions should balance statistical improvement with practical feasibility.