Metabolic Responses to Exercise THE EFFECTS OF RUNNING SPEED ON THE METABOLIC AND MECHANICAL ENERGY COSTS OF RUNNING

THE EFFECTS OF RUNNING SPEED ON THE METABOLIC AND MECHANICAL ENERGY COSTS OF RUNNING. Chad Harris, Mark Debeliso, Kent J. Adams. JEPonline. 2003;6(3):28-37. This study assessed the influence of speed on the metabolic and the mechanical cost to run a given distance. Trained male runners (n=12) performed 2 treadmill run trials of 8 min duration at each of 6 speeds (range 2.33 to 4.0 m/s). Oxygen uptake values were normalized for running speed providing a metabolic task cost variable (MBTC, ml/kg/m). Mechanical work was calculated from digitized video records using three different algorithms. Values were normalized for running speed giving mechanical task cost variables (MTC, J/kg/m). No change in the group mean metabolic task cost was found across speeds (p=0.25). In contrast, mechanical task cost decreased as running speed increased (p<0.001). The three mechanical work algorithms resulted in MTC characteristics that were significantly different from each other (p<0.001). This study suggests that metabolic cost per distance remains relatively constant across running speeds while mechanical cost per distance decreases as speed increases.