“Tailored” step test for rapid, accurate and safe VO2max determination in healthy elderly. Ceciclia Bellotti, Lorenzo Casiello, Silvia Pogliaghi Faculty of Kinesiology, University of Verona, Italy PURPOSE: The study aimed at developing and validating a “tailored” version of the Åstrand step test, suitable for VO2max determination in healthy elderly. Furthermore, we tested the hypothesis that a direct measure (compared to estimation) of the step test VO2, adds accuracy to VO2max determination in this population, characterized by low fitness and muscle strength and reduced coordiantive ability. METHODS: In 27 healthy elderly (age 68+5, 14 ♂, 13 ♀) a target VO2 (tVO2) for the step test was calculated as 60% of the VO2max (predicted based on their referred activity pattern). Thereafter, subjects performed a 5-min test, on a 30 cm step, with a stepping rate (10-25 steps*min-1) “tailored” based on tVO2 and the predicted cost of stepping. Heart rate (HR) and VO2 were measured using a portable, hand-held, metabolic analyzer. VO2max was estimated based on Åstrand equation and age correction using either tVO2 (t-estVO2max) or measured VO2 (m estVO2max). Finally, VO2max was measured directly (dVO2max) during an incremental cycling test to exhaustion with breath by breath determination of cardiorespiratory variables, with a traditional metabolic chart. Agreement among t estVO2max, m estVO2max and dVO2max was evaluated by Bland Altman analysis. RESULTS: All the subjects completed the incremental exercise to exhaustion (maximal HR 98±7% of age-predicted value, maximal respiratory quotient 1.1±0.04). Mean ± standard deviation dVO2max was 27±5 ml*kg-1*min-1. All the subjects were also able to complete the “tailored” step test with no difficulty. m estVO2max was not significantly different from dVO2max (bias -0.3, not different from 0; precision 4.1 ml*kg-1*min-1). On the contrary, t-estVO2max was significantly underestimated compared to dVO2max (bias -2.3, ≠ 0; precision 4.6 ml*kg-1*min-1). CONCLUSION: The study developed and validated a “tailored” version of the Åstrand step test, suitable for a rapid (5 min duration), safe (submaximal test) and accurate (unbiased) VO2max determination in healthy elderly individuals. In this population, estimation of the step test VO2 leads to a small (9%) yet significant error in VO2max estimation. Therefore, our data suggest that a direct measure of the step test VO2 should be performed to assure accuracy to VO2max.estimation. The study was supported by Cosmed, Italy.
"Tailored" step test for a rapid, accurate and safe VO2max determination in healthy elderly
BELLOTTI, Cecilia;POGLIAGHI, Silvia
2009-01-01
Abstract
“Tailored” step test for rapid, accurate and safe VO2max determination in healthy elderly. Ceciclia Bellotti, Lorenzo Casiello, Silvia Pogliaghi Faculty of Kinesiology, University of Verona, Italy PURPOSE: The study aimed at developing and validating a “tailored” version of the Åstrand step test, suitable for VO2max determination in healthy elderly. Furthermore, we tested the hypothesis that a direct measure (compared to estimation) of the step test VO2, adds accuracy to VO2max determination in this population, characterized by low fitness and muscle strength and reduced coordiantive ability. METHODS: In 27 healthy elderly (age 68+5, 14 ♂, 13 ♀) a target VO2 (tVO2) for the step test was calculated as 60% of the VO2max (predicted based on their referred activity pattern). Thereafter, subjects performed a 5-min test, on a 30 cm step, with a stepping rate (10-25 steps*min-1) “tailored” based on tVO2 and the predicted cost of stepping. Heart rate (HR) and VO2 were measured using a portable, hand-held, metabolic analyzer. VO2max was estimated based on Åstrand equation and age correction using either tVO2 (t-estVO2max) or measured VO2 (m estVO2max). Finally, VO2max was measured directly (dVO2max) during an incremental cycling test to exhaustion with breath by breath determination of cardiorespiratory variables, with a traditional metabolic chart. Agreement among t estVO2max, m estVO2max and dVO2max was evaluated by Bland Altman analysis. RESULTS: All the subjects completed the incremental exercise to exhaustion (maximal HR 98±7% of age-predicted value, maximal respiratory quotient 1.1±0.04). Mean ± standard deviation dVO2max was 27±5 ml*kg-1*min-1. All the subjects were also able to complete the “tailored” step test with no difficulty. m estVO2max was not significantly different from dVO2max (bias -0.3, not different from 0; precision 4.1 ml*kg-1*min-1). On the contrary, t-estVO2max was significantly underestimated compared to dVO2max (bias -2.3, ≠ 0; precision 4.6 ml*kg-1*min-1). CONCLUSION: The study developed and validated a “tailored” version of the Åstrand step test, suitable for a rapid (5 min duration), safe (submaximal test) and accurate (unbiased) VO2max determination in healthy elderly individuals. In this population, estimation of the step test VO2 leads to a small (9%) yet significant error in VO2max estimation. Therefore, our data suggest that a direct measure of the step test VO2 should be performed to assure accuracy to VO2max.estimation. The study was supported by Cosmed, Italy.
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