Energy expenditure during walking and jogging

Background. The aim of this investigation was to compare the physiological and subjective responses during treadmill walking and jogging at several co rresponding speeds in physically active young women. Methods. Experimental design: Maximal oxygen uptake was determined during a continuous treadmill test to exhaustion The walking protocol consisted of treadmill walking for five min at each of the following speeds: 4.0, 5.6, 7 .2, 8.0, 8.8, 9.6 and 10.4 km.hr(-1). The jogging protocol consisted of tre admill walking for five min at 4.0, and 5.6 km.hr(-1) and treadmill jogging for five min at each of the following speeds: 7.2, 8.0, 8.8, 9.6 and 10.4 km.hr(-1). Setting: This research was performed at Washington University Sc hool of Medicine. Participants: Fifteen healthy Women (mean+/-SE, age; 26.9 +/-1.4 yrs, BMI; 22.5+/-0.70, (V) over dot O-2max; 41.9+/-1.9 ml.hr(-1).min (-1)) performed a maximal treadmill exercise test, a walking test and a jog ging test. Results. The rate of oxygen consumption, calculated energy expenditure per distance (kJ.hr(-1).mile(-1)) and heart rates were significantly higher dur ing walking compared to jogging at treadmill speeds greater than or equal t o8.8 km.hr(-1). Plasma lactate concentration and respiratory exchange ratio were significantly higher at treadmill speeds greater than or equal to8.0 km.hr(-1) during walking as compared to jogging. Subjects subjectively rate d their exertion during walking as being significantly greater when compare d to jogging across the range of overlapping treadmill speeds. Conclusions. These findings demonstrated that walking at speeds greater tha n or equal to8.0 km.hr(-1) resulted in rates of energy expenditure that wer e as high or higher than jogging at the same speeds. Also, the higher rates of energy expenditure during walking as compared to jogging at speeds grea ter than 8.0 km.hr(-1) were associated with higher heart rates, RER, RPE an d plasma lactate response.