The effect of handrail support on oxygen uptake during steady-state treadmill exercise.

Abstract

Rationale: Heart rate (HR) and oxygen consumption (VO(2)) are indicators of the intensity of exercise. Handrail support has been shown, during maximal treadmill testing, to blunt HR and VO(2) responses at a particular speed and grade, resulting in an increased treadmill time and overprediction in aerobic capacity.

Objectives: This study was designed to determine if handrail support would similarly blunt HR and VO(2) responses during steady-state treadmill exercise at intensities typical of exercise training.

Methods: Healthy volunteers (age, 38-60 years; N = 10) performed maximal treadmill exercise to define VO2max (35.4 +/- 6.5 mL kg(-1) min(-1)) and ventilatory threshold (26.4 +/- 5.8 mL kg(-1) min(-1)). They also performed 3 random steady-state exercise bouts including free arm swing, handrail support-resting, and handrail support-gripping (HRS-G). Each test consisted of three 5-minute stages with intensity levels corresponding to 75%, 85%, and 95% of the speed and grade at ventilatory threshold.

Results: There were significant (P < .05) differences in HR and VO2 at the 75%, 85%, and 95% ventilatory thresholds in HRS-G (108, 114, and 121 beats min and 17.2, 18.0, and 20.6 mL kg min, respectively) versus handrail support-resting (114, 126, and 137 beats min and 19.5, 21.8, and 23.9 mL kg min, respectively) and HRS-G versus free arm swing (120, 130, and 142 beats min and 20.3, 22.8, and 26.1 mL kg min, respectively). Rating of perceived exertion was significantly (P < .05) different between HRS-G (1.8, 2.4, and 3.1) and free arm swing (2.2, 2.9, and 3.6) at all intensities and between HRS-G (2.4 and 3.1, respectively) and handrail support-resting (3 and 3.7, respectively) at the 85% and 95% ventilatory thresholds.

Conclusion: Gripping and, to a lesser degree, resting the hands on the handrails during steady-state treadmill walking will blunt responses during exercise training and may result in less predictable exercise program.