Manipulating rest interval length in sprint interval training alters post-exercise hypotension and within-session oxygen consumption

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Introduction It is well documented that sprint interval training (SIT) elicits similar or even superior health and performance benefits compared to continuous aerobic training, albeit a significantly reduced time commitment. A distinctive feature of intermittent exercise training is the possibility to modulate the different training variables resulting in numerous different protocols. This makes this training approach infinitely variable and individually adjustable. The purpose of this study was to examine the effects of manipulating the rest interval length during SIT on post-exercise hypotension and within-session oxygen consumption. Methods Thirty healthy adults (aged 30.9 ± 8.7 years; BMI 22.1 ± 2.3 kg/m2; 14 males, 16 females) participated in this study. All participants completed two SIT protocols consisting of 4x 30-seconds all-out cycling sprints interspersed by either 1 (R1) or 3 (R3) minutes of active recovery. Both before and throughout the 45 minutes after the training, peripheral systolic (pSBP) and diastolic (pDBP) blood pressure, central systolic (cSBP) and diastolic (cDBP) blood pressure, pulse wave velocity (PWV), and heart rate (HR) were assessed. Throughout the SIT protocols, oxygen consumption (VO2) was continuously monitored. Results Only after R3 a significant reduction in pSBP, pDBP, cSBP, cDBP, and PWV could be detected. Significant interaction effects could be detected in pSBD, pDBP, cSBP, cDBP, and PWV. HR significantly increased after both conditions (Table 1.). No significant (p>0.05) differences in time spent at 75%, 85%, 95%, and 100% of maximal VO2 between R1 and R3 could be detected. Conclusion Rest interval manipulation seems to affect hemodynamic responses to SIT with longer resting intervals resulting in more substantial post-exercise hypotension effects. Time spent at a high percentage of maximal VO2 was not attenuated by rest interval manipulation. These results add crucial information for the prescription of SIT.