Comparison of bioenergetics of walking during a multistage incremental shuttle walk test and a 6-min walk test in active older adults

Abstract

The goal of the present research was to compare the bioenergetics variability of walking, during the 6-min walk test (6-MWT) and a multistage incremental shuttle walk test (MISWT) in an active older population. Twenty-two healthy physically active older adults with a group mean age of 70.4 ± 5.8 years completed the 6-MWT and the MISWT. Heart rate (HR), walking speed and walking $\dot{V}$O₂ were measured throughout each test with a portable metabolic cart. Strong correlations were found for the $\dot{V}$O₂ peak and the walking speed (r = 0.91 and r = 0.89 respectively for 6-MWT and MISWT). Differences in $\dot{V}$O₂ peak values were analysed with a paired Student’s t test. Repeated measures ANOVA were conducted to detect differences between tests. The Bland and Altman plot indicates that the average difference between both tests was 2.5 ml kg⁻¹ min⁻¹. MISWT $\dot{V}$O₂ peak means were significantly greater than the 6-MWT $\dot{V}$O₂ peak mean values (21.6 ± 5.3 vs. 18.9 ± 4.5 ml kg⁻¹ min⁻¹) which indicate bioenergetics differences between the two walking tests. Thus, the MISWT and 6-MWT elicited different walking $\dot{V}$O₂ peak and HR suggesting that the MISWT field test challenge the participants to a higher level of cardiovascular and respiratory stress. The walking $\dot{V}$O₂ peak recorded for the MISWT was significantly greater than the 6-MWT. Consequently, both tests seem to measure different facets of the aerobic capacity. MISWT seems to be a better indicator of maximal aerobic power whereas the 6-MWT provides more relevant information regarding aerobic endurance in aging population.