Rationale:

Heart rate (HR) and oxygen consumption (VO₂) are indicators of the intensity of exercise. Handrail support has been shown, during maximal treadmill testing to blunt the HR and VO₂ responses at a particular speed and grade, resulting in an increased treadmill time and over-prediction in aerobic capacity.

Objectives:

This study was designed to determine if handrail support would similarly blunt HR and VO₂ responses during steady state treadmill exercise, at intensities typical of exercise training.

Methods:

Healthy volunteers (age 38-60) (n = 10) performed maximal treadmill exercise to define VO₂max (35.4 +/- 6.5 ml/kg/min) and ventilatory threshold (V_T) (26.3 +/- 5.9 ml/kg/min). They also performed three random steady state exercise bouts including: free arm swing (FAS), handrail support - resting (HRS-R), 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 V_T.

Results:

There were significant (P < 0.05) differences in HR, VO₂, and ventilation (V_E) at 75, 85, and 95% V_T with HRS-G (108, 115, 121 bpm; 17.2, 19.0, 20.6 ml/kg/min & 33, 38, 41 l/min) versus HRS-R (114, 126, 137 bpm, 19.5, 21.8, 23.9 ml/kg/min & 38, 43, 48 l/min) and HRS-G versus FAS (120, 130, 142 bpm, 20.3, 22.8, 26.1 ml/kg/min & 39, 44, 50 l/min). Significant differences were also found for HR between HRS-R (114 bpm) and FAS (120 bpm) at 75% V_T, and for VO₂ between HRS-R and FAS (23.9 vs 26.1 ml/kg) at 95% V_T. RPE was significantly (P < 0.05) different between HRS-G (1.8, 2.4, 3.1) and FAS (2.3, 2.9, 3.6) at all intensities and between HRS-G (2.4, 3.1) and HRS-R (3, 3.8) at 85 & 95% V_T.

Conclusion:

Gripping, and to a lesser degree, the handrails during steady state treadmill walking will markedly blunt responses during exercise training and may result in less predictable exercise program.