High intensity walking time is a key determinant to increase VO2peak after 5‐month interval walking training in middle‐aged and older people

Abstract

Background and hypothesisIt has been suggested that a substantive proportion of participants in exercise training program showed no increase in peak aerobic capacity (VO2peak) even after the same period of training as those who showed a significant increase in VO2peak. We examined the hypothesis that this would be caused by an inter‐individual variation in exercise intensity relative to individual VO2peak for training.MethodsMiddle‐aged and older men and women (n=696, aged 65±7(SD) years) participated in the study. They were instructed to perform interval walking training (IWT) to repeat ≥5 sets of fast and slow walking for 3 min each at ≥70% and 40% VO2peak for walking, respectively, per day ≥4 days/wk for 5 months, during which period exercise intensity and time were measured with a portable calorimeter every min and the measurements were transferred to a sever computer via the internet every 2 weeks.ResultsThe average fast, slow, and total walking time during IWT for 5 months were 87±65(SD), 99±87, and 186±126 min/week, respectively. After training, VO2peak increased by 2.9±3.9(SD) ml/kg/min on average. When we analyzed the relationship between the increase in VO2peak from the baseline and the fast, slow, and total walking time per week during IWT, respectively, we found that the increase in VO2peak was in proportion to the fast walking time in the range of 0 to 50 min/week (R2=0.92, P<0.001), but above the range, it reached the steady level of 3.6 ml/kg/min. In contrast, the increase in VO2peak after training was not significantly correlated with either slow (P=0.06) or total walking time (P=0.3) during IWT for 5 months.ConclusionHigh intensity walking time during IWT is a key determinant to increase VO2peak in middle‐aged and older people.Support or Funding InformationThis study was supported by a grant from the Japan Society for the Promotion of Science (15H04680).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.