Speed Effects on the Accuracy of Heart Rate as Oxygen-Uptake Indicator in Short-Distance Shuttle Running

Abstract

Purpose: Despite the accuracy of heart rate (HR) as an indicator of the aerobic engagement has been evaluated in several intermittent on-court activities, its validity as an oxygen uptake (${\dot{V}}_{O_2}$) indicator during shuttle running over short paths remains uncertain. Moreover, it is unclear whether speed may affect such validity. This study evaluated the HR ability in estimating the ${\dot{V}}_{O_2}$ during 5-m shuttle running at different speeds. Methods: ${\dot{V}}_{O_2}$ and HR of 12 physically active young men were recorded during an incremental forward running (FW) protocol and a 5-m shuttle test at 50%, 60%, and 75% of maximal aerobic speed (MAS). Slope and intercept of the relationship between HR and ${\dot{V}}_{O_2}$ (HR/${\dot{V}}_{O_2}$) were individually determined, in both protocols. The HR measured during the shuttle test was used in the FW HR/${\dot{V}}_{O_2}$ to estimate ${\dot{V}}_{O_2}$ at each shuttle speed. A paired Student's t-test compared slopes and intercepts of the two HR/${\dot{V}}_{O_2}$. A two-way RM-ANOVA and an equality test examined, respectively, the differences and the equality between measured and estimated ${\dot{V}}_{O_2}$. Lastly, a Bland-Altman plot described the accuracy and precision of the estimated ${\dot{V}}_{O_2}$ at each shuttle intensity. Results: Slopes and intercepts of the HR/${\dot{V}}_{O_2}$ appeared not different between FW and shuttle running. At 50%MAS, HR underestimated the ${\dot{V}}_{O_2}$ (~7%), whereas returned accurate values at the two higher velocities, although with high variability (±18%). Conclusions: When using HR as ${\dot{V}}_{O_2}$ indicator during shuttle running over short paths, a separated analysis of the HR validity as ${\dot{V}}_{O_2}$ indicator is recommended especially when administering different exercise intensities.

Keywords: Cardiorespiratory response; changes of direction; intermittent running; performance assessment; small-sided games; team sports; testing; turning.