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 (> 14.4 km.h-1) and high power (> 20 W.kg-1) were quantified using a 10 Hz 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 ± 1.4 kcal.min-1), whereas estimated energy expenditure was higher during the linear condition (8.7 ± 2.1 cf. 6.5 ± 1.5 kcal.min-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
