TREADMILL WALKING IN OLD-AGE MAY NOT REPRODUCE THE REAL LIFE SITUATION

Objective: In a preliminary study in our laboratory, healthy elderly people had a higher heart rate during treadmill walking than during corridor walking at the same speed. The objective of this study was to determine whether this initial observation, (1) persisted after repeated testing, (2) was present in younger adults, (3) was due to wearing a mouthpiece during treadmill walking, or (4) was due to a change in gait. Design: A study of elderly and young volunteers undergoing repeated testing, with comparison of treadmill walking with corridor walking. Setting: The Royal Free Hospital School of Medicine. Participants: Twelve healthy elderly (71-80 years) and 12 healthy young (21-37 years) volunteers. Main Outcome Measures: Heart rate (beats/min) and step rate (steps/min) during comfortable self -paced corridor walking and during treadmill walking at the same speed. Main Results: The elderly subjects had higher heart rates during treadmill walking than during corridor walking at the same speed (mean difference = 6 beats/min, 95% Confidence Interval (CI) = 1 to 10). This difference increased (to a mean of 11 beats/min, 95 % CI = 5 to 16) when a mouthpiece was worn on the treadmill. These differences persisted after repeated testing. The young subjects did not have higher heart rates on the treadmill, (with or without the mouthpiece). In both groups, step rate was lower (95% CI = -9 to -2, elderly; -5 to -2, young) during treadmill walking, corresponding to a 3% increase in stride length. Conclusion: The heart rate response to treadmill walking in healthy elderly people may be less representative of the 'real life' situation than in younger adults.