The Effect of a Submaximal Incremental Running Test on Post Exercise Hypotension in Normotensive and non Normotensive Subjects

Purpose: Arterial blood pressure is strongly influenced by exercise modality and intensity in both normotensive and non-normotensive subjects. Exercise can also contribute to the temporary decrease in blood pressure during the post-exercise period, a phenomena known as post-exercise hypotension (PEH), with vigorous intensity exercises having higher effects. The aim is to investigate the PEH response following a submaximal incremental running test on a treadmill and to compare the decrease magnitude in normotensive and non-normotensive subjects. Methods: 15 young individuals (female=5; male=10) aged 24.8±2.8years were allocated in 2 groups based on their pre-test systolic blood pressure (sBP). Group 1 included subjects with sBP≤129mmHg, whereas group 2 those who had pre-test sBP>129mmHg. Subjects’ sBP was measured 15-min before and 30-min after the test. Volunteers completed a familiarization session and, after 48-hours, one submaximal incremental running test. The tests were carried out on a treadmill and consisted of a 3-min warm-up at 1% gradient, fixed for the entire duration of the test, at a comfortable speed. Afterwards, the speed was increased by 1 km/h every 2-min until the end point of the test determined by their 90% estimated heart rate max. Means and standard deviations of pre-test and post-test sBP were calculated for both groups. Repeated measures mixed models were performed to examine the effects of the submaximal test on subject’s sBP. Subjects were considered the random effect, whereas the groups (1 Vs 2) and testing time (pre Vs post) were treated as the fixed effect. Statistical significance was set at p<0.05. Results: Statistically significant (p<0.05) reductions in sBP after the submaximal incremental test were evident in both groups. Group 1 reached an average reduction in sBP of 7mmHg (pre=117±7; post=110±5), while Group 2 had an average reduction of 13mmHg (pre=139±13; post=126±6). PEH thus occurred independently of pre-test sBP levels.