Improving assessment of post-exercise hypotension as a predictor of training efficacy

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