Background: It is currently not known how much walking should be advocated for good health in an adolescent population. Step count recommendations for minimum time in moderate intensity activity have been translated predominantly from treadmill walking. The aim of this study was to compare the energy cost of walking on a treadmill with overground walking in adolescent girls. Method: Twenty six adolescent girls undertook resting metabolic measurements for individual determination of one MET using indirect calorimetry. Energy expenditure was subsequently assessed during treadmill and overground walking at slow, moderate and fast walking speeds for 4 – 6 minutes. Treadmill step rates were matched overground using a metronome. Result: The energy cost of treadmill walking was found to be significantly greater than and not equivalent to overground walking at 133step∙min-¹ (equivalent to the fast walking pace) V̇O2 3.90 [2.78 to 5.01] P<0.001, MAPE =18.18%, METs 0.77[0.54 to 34 1.00] P<0.001, MAPE =18.16%. The oxygen cost per step ( V̇O2 ml· step -¹) was significantly greater and not equivalent on the treadmill at 120 and 133step∙min-¹, 0.43 [0.12 to 0.56] P<0.05, 36 MAPE =10.12%, 1.40[1.01 to 1.76] P<0.001, MAPE =17.64% respectively. Conclusion: The 37 results suggest that there is a difference in energy cost per step of walking on a treadmill and overground at the same step rate. This should be considered when utilising the treadmill in energy expenditure studies. Studies which aim to provide step recommendations should focus on overground walking where most walking activity is adopted.
- ambulatory activity
- assessment mode