Energy expenditure, metabolic power and high speed activity during linear and multi-directional running.

OBJECTIVES: The purpose of the study was to compare measures of energy expenditure derived from indirect calorimetry and micro-technology, as well as high power and high speed activity during linear and multi-directional running.

DESIGN: Repeated measures.

METHODS: Twelve university standard team sport players completed a linear and multi-directional running condition. Estimated energy expenditure, as well as time at high speed (>14.4kmh-1 ) and high power (>20Wkg-1 ) were quantified using a 10Hz micro-technology device and compared with energy expenditure derived from indirect calorimetry.

RESULTS: Measured energy expenditure was higher during the multi-directional condition (9.0±2.0 cf. 5.9±1.4kcalmin-1 ), whereas estimated energy expenditure was higher during the linear condition (8.7±2.1 cf. 6.5±1.5kcalmin-1 ). Whilst measures of energy expenditure were strongly related (r>0.89, p<0.001), metabolic power underestimated energy expenditure by 52% (95% LoA: 20-93%) and 34% (95% LoA: 12-59%) during the multi-directional and linear condition, respectively. Time at high power was 41% (95% LoA: 4-92%) greater than time at high speed during the multi-directional condition, whereas time at high power was 5% (95% LoA: -17-9%) lower than time at high speed during the linear condition.

CONCLUSIONS: Estimated energy expenditure and time at high metabolic power can reflect changes in internal load. However, micro-technology cannot be used to determine the energy cost of intermittent running.