Comparison of walking parameters and cardiorespiratory changes during the 6-minute walk test in healthy sexagenarians and septuagenarians.
BACKGROUND
The 6-minute walk test (6-MWT) is commonly used in research, with a focus on walking distance parameters rather than the physiological parameters. Even though it has been reported that the distance walked during the 6-MWT decreases with age, the adaptation of cardiorespiratory functions in healthy older adults remains to be studied.


OBJECTIVE
The primary objective of this study was to compare the changes in walking distance and cardiorespiratory parameters during the 6-MWT in healthy sexagenarians and septuagenarians. A secondary objective was to determine the cardiorespiratory parameters and functional performance variables that best predict the distance covered during the 6-MWT.


METHODS
Ten healthy sexagenarians (G60, mean age 63.6 +/- 3.3 years) and 10 septuagenarians (G70, mean age 76.0 +/- 3.3 years) performed the 6-MWT while the distance, heart rate and oxygen uptake (VO(2)) were recorded. The subjects also completed the Timed-Up-and-Go, the Berg Balance Scale and the Human Activity Profile to establish their functional level.


RESULTS
Results showed that G60 reached significantly greater (p < 0.05) distance and VO(2) values during the 6-MWT than G70. In contrast, the energy cost of walking (O(2) cost) and heart rate did not differ between the 2 groups. Correlational analyses of the combined groups revealed that VO(2) was the variable that showed the strongest correlation with walking distance during the 6-MWT.


CONCLUSIONS
Results revealed that, while G60 achieved a greater level of walking performance than G70, the 2 groups maintained the same level of walking efficiency (O(2) cost) during the walk. Both groups adjusted their walking speed to have an oxygen consumption rate at a level sufficient to meet the energy demands of the task and prevent early exhaustion. Therefore, the 6-MWT appears to be a simple tool that can be used to assess cardiorespiratory parameters in older adults and be sensitive enough to detect differences between sexagenarians and septuagenarians.
Department of Exercise Science, Concordia University, Montreal, Que., Canada.
Cindy L
CL
Hovington
Sylvie
S
Nadeau
Alain
A
Leroux
D000222:Adaptation, Physiological / Q000502:physiology*; D000368:Aged; D000375:Aging / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology*; D016138:Walking / Q000502:physiology*