High-intensity Interval Versus Moderate-intensity Continuous Heated Water-based Exercise On Cardiovascular Variables In Hypertensive Older Individuals

Abstract

PURPOSE: To evaluate acute hemodynamic and autonomic responses to high-intensity interval (HIIT) vs moderate-intensity continuous (MICE) exercise in heated water-based in older hypertensive individuals. METHODS: 15 sedentary older hypertensives were randomized in 2:2:1 to HIIT, MICE or without exercise (CON) sessions. Systolic/diastolic blood pressure (SBP/DBP), pulse wave velocity (PWV), endothelial function (EF) and variability of heart rate (HRV) were assessed before (pre), immediately after (post) and 45 min after intervention (rec). HIIT was consisted of warm-up (4 min), 21 min of 1 min of high-intensity alternating with 2 min of walking at moderate-intensity. MICE was performed by 4 min warm-up followed by 26 min of walking at moderate-intensity. Sessions were controlled using Rating Perceived of Exertion Scale (RPE).Two-way ANOVA (repeated measures) was used to indicate interventions differences and Bonferroni post hoc was used to identify significant differences (p<0.05). RESULTS: No significant differences were found for PWV and EF. HRV showed an increase in the μHP (high frequency band) when compared the moments PRE vs REC within CON group (PRE: 906 ± 132 ms vs REC: 942 ± 148 ms; p = 0.007). Moreover, even though POST-HIIT session we found a decrease of HFaHP (PRE: 413 ± 874 ms2 vs POST: 272 ± 716 ms2; p < 0.001), during REC only the HIIT group was able to increase the HFaHP index (POST: 272 ± 716 ms2 vs REC: 530 ± 1336 ms2; p < 0.001). The changes in HFaHP during REC was followed by a decreased of LFHP (low frequency band) index after HIIT (POST: 49 ± 24 n.u. vs REC: 33 ± 18 n.u.; p = 0.013). None difference was found in pre SBP/DBP (p>0.05). Although in post moment SBP was different between CON (153±4) vs MICE (141±6, p<0.02) and CON vs HIIT (136±5, p<0.001), with no difference in DBP. For REC, only CON (131±3) vs HIIT (123±4, p<0.02), with no difference in CON vs MICE and MICE vs HIIT (p>0.05) were founded. Only HIIT modality was able to return the SBP values to the PRE (122±4) in REC moment (123±4, p<0.66), but increasing in POST (136±5) moment comparing with PRE (p<0.01) and REC (p<0.02). For DBP, all intensities increase the values in POST (p<0.05) and maintain greater in REC moment comparing with pre (p<0.05). CONCLUSION: Water-based HIIT using RPE may be a time-efficient intervention in hypertension treatment of older individuals.