High-intensity interval training improves acute plasma volume responses to exercise that is age dependent.

Georges Jabbour,Pascale Mauriège,Denis R Joanisse,Luc J Martin,Horia-Daniel Iancu,Hassane Zouhal

doi:10.14814/phy2.13609

Abstract

Plasma volume (PV) is affected by several factors including age, physical training and, acutely, by exercise intensity. The purpose of this study was to investigate the effects of 6 weeks of high‐intensity interval training (HIT) on PV and blood pressure (BP) changes among sedentary individuals. Thirty subjects aged between 18 and 71 years [body mass index=30.1(1.2) kg/m2] completed a 6‐weeks HIT program. Anthropometric and fitness variables were obtained at pre‐ and post‐ HIT. PV variations during warm‐up and after supramaximal cycling test (SCT) were calculated using two methods based on Hematocrit (Ht) and Hemoglobin (Hb) measures. After both the warm‐up and SCT, PV decreased significantly among participants at pre‐ and at post‐HIT (P < 0.01). However, PV decreases were significantly greater at pre‐HIT compared with post‐HIT during warm‐up and after SCT (P < 0.01, respectively). In addition, at pre‐HIT, a positive relationship was found between age and both PV variations at warm‐up and after SCT (r 2 = 0.55 and r 2 = 0.46; P < 0.01 respectively). However, no relationship was found during the post‐HIT period. After SCT and after both visits, only body weight predicted 22% of PV variations. In the current study, a significant relationship was found between systolic and diastolic BP improvements and PV variations in post‐HIT (r 2 = 0.54 and r 2=0.56, P < 0.05, respectively). Our results suggest that HIT may improve PV values and reduce the effects of age on the decrease in PV. These interventions led to improvements in systolic and diastolic BP values among participants.

Highlights

Plasma volume (PV) variations are considered a form of body fluid adaptation in response to several factors such as age (Berthoin et al 2003), training level (Moussa et al 2003) and exercise intensity (El-Sayed et al 2011)
Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society anthropometric, fitness, PV, and blood pressure (BP) measurements were conducted after the final training session to obtain information on the potential chronic lasting effects of high-intensity interval training (HIT)
A positive and significant correlation was found between PV decreases and age among participants during both warm-up (r2 = 0.55, P < 0.05) and at the end of supramaximal cycling test (SCT) (r2 = 0.46, P < 0.05) (Fig. 1)

Summary

Introduction

PV variations are considered a form of body fluid adaptation in response to several factors such as age (Berthoin et al 2003), training level (Moussa et al 2003) and exercise intensity (El-Sayed et al 2011). Several investigators (Leaf 1984; Phillips et al 1984) have observed that by aging individuals have difficulty maintaining body fluid balance, contributing to fluctuations in PV. This phenomenon has been observed at rest and acutely during exercise (Phillips et al 1993), with larger PV decreases observed in response to exercise (Hebestreit et al 1996). These PV decreases affect heart rate and impact blood flow to active muscles (Kenney and Ho 1995).

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