Energy cost of running and walking in young women.

The energy cost of level walking and level and grade running was determined in 7 active women with max VO2 = 50.7 ml/kg-min. Speeds investigated were 4 to 8 km/hr walking and 8 to 14.5 km/hr running. The validity coefficients of several procedures for estimating energy expenditure during locomotion [4 for running (6)(11)(16)(17); 3 for walking (6)(12)(17)] were determined. Correlation coefficients between actual and predicted values were 0.949 to 0.951 with standard errors of estimate 0.79 to 0.80 kcal/kg-hour for walking and 0.856 to 0.975 with standard errors of estimate 0.40 to 0.60 kcal/kg-hour for running. VO2 and kcal energy cost values were similar to those previously reported on men at equivalent walking and running speeds. Efficiency of running based on lift work done was about 25%. Lift work for women was slightly less than values previously reported for men at walking but was slightly more at running. These differences did not appear to have a significant effect on energy expenditure.