Abstract
Previous research has provided evidence that aerobic HIIT exercise can induce important physiological adaptations and elicit improvements in health and fitness parameters. However, most of the research has taken place in a laboratory setting with specialized equipment and monitoring devices. It begs the question, is HIIT accessible to the general aging population? The objective of the current research was to employ an age-predicted HRmax to prescribe a minimally invasive 4x4 cycle ergometer HIIT protocol. Ten participants (age: 64.2 ± 6.1) completed a non-weight-bearing cycle ergometer protocol for 6 weeks. Significant Pearson correlations were found between %HRmax and W/kg in seven of the ten participants. Two participants showed significant correlations between RPE and W/kg. Half of the participants exhibited a significant correlation between %HRmax and RPE. Pre- to post-intervention measures demonstrated a significant increase in lower limb strength by the 10-repetition chair sit-to-stand (p = 0.004) and 30-second sit-to-stand (p = 0.021). Increased functional capacity demonstrated by TUG (p = 0.001) and SB (p = 0.034) also presented significant differences pre- to post-intervention. There was a 96% participant session completion rate. These data imply that a simple 4x4 cycle ergometer HIIT protocol prescribed using a %HRmax is effective at increasing lower-limb power/strength and can be used in the general older adult population without excessive oversight. Our intervention protocol demonstrates that 6 weeks of cycle ergometer HIIT is an adequate amount of time to result in lower limb strength and functional capacity improvements in active older adults.