Comparable blood pressure reductions after indoor and outdoor walking exercise

Although there is a trend toward outdoor activities, limited research has examined the effects of outdoor exercise on blood pressure. This study aimed to compare the Systolic (sBP) and Diastolic (dBP) Blood Pressure, Heart Rate (HR) response, Post-Exercise Hypotension (PEH) and Rate Pressure Product (RPP) following indoor and outdoor activities. Thirty-seven participants (18 females = age: 24.7 ± 0.7 years, BMI: 21.1 ± 2.1 kg/m², MET*week: 3779 ± 3037; 19 males = age: 24.9 ± 0.5 years, BMI: 24.1 ± 2.6 kg/m², MET*week: 3000 ± 730) completed an outdoor hike (H) (~3800 m) and an indoor maximal walking test (MWT). During both sessions, sBP, dBP and HR were measured 15-min before (PRE), immediately after (POST), 15-min (POST-15) and 30-min (POST-30) after the sessions. Mean differences and standard deviations of all variables, along with PEH and RPP, were determined. Repeated-measures mixed models evaluate the effects of indoor and outdoor sessions on hemodynamic variables. Paired t-tests compared PEH between settings. Regardless of sessions PRE measurements were higher (p < 0.0001) than POST-30 for sBP (H: 10.4 ± 2.1 mmHg; MWT: 12.3 ± 2.3 mmHg), dBP (H: 4.3 ± 1.9 mmHg; MWT: 4.5 ± 1.7 mmHg), HR (H: -5.4 ± 2.2 bpm; MWT: -7.8 ± 2.5 bpm) and RPP (H: 140.6 ± 296.6 mmHg*bpm; MWT: 38.6 ± 323.5 mmHg*bpm). No significant difference in PEH (0.9 ± 11.3 mmHg) was found between sessions. PEH occurred regardless of PRE values, confirming the positive effect of physical activity on reducing BP.