Background: Overweight is one of major risk factor for cardiovascular disease and other chronic disease. At now, more than 1.9 billion adults are overweight in the world. Lack of
physical activity is one of the main causes of overweight in adults. Increasing energy expenditure of physical activity is the key to weight control in overweight people. Walking and jogging are two
common exercises in overweight people. The relationship between energy expenditure of walking and jogging in overweight people is still not clear. This paper probes into characteristics of energy
expenditure and physiology of overweight adult women at the same speed gradient of walking and jogging.
Methods: Twenty three overweight and twenty two normal weight adult women(age: 22.0±1.5 years) participated in the study. Their maximal oxygen uptake was measured by a maximal
treadmill exercise test using a modified Bruce protocol. The resting energy expenditure and the energy expenditure of overground walking and jogging were measured by Cortex portable gas metabolism
system. The overground walking speed from low to high were 4.0km/h, 4.5km/h, 5.0km/h, 5.5km/h, 6.0km/h, 6.5km/h and 7.0km/h. The overground jogging speed were 6.0km/h, 7.0km/h and 8.0km/h. The
duration of each speed was 6 minutes. Net energy expenditure of each speed was calculated as energy expenditure minus resting energy expenditure.
Results: When the walking speed over 5.5km/h (including 5.5km/h) and jogging speed over 7.0km/h (including 7.0km/h), the energy expenditure, net energy expenditure and heart rate of
overweight women were significantly higher than normal weight women(P＜0.05). When walking speed was 6.0km/h, energy expenditure and net energy expenditure of overweight women were significantly lower
than jogging at the speed of 6.0km/h(P＜0.01). However, when walking speed was 7.0km/h, energy expenditure, net energy expenditure, heart rate and RPE of overweight women were significantly higher than
jogging at the speed of 7.0km/h(P＜0.05).
Conclusions: These results demonstrate that the differences of BMI will result in differentiations of energy consumption and physiological indexes of women when walking and jogging at
a certain speed. When speed reach and exceed 7.0km/h, walking will consume more energy than jogging. As far as the weight control of overweight people is concerned, the effect of walking at this speed
is better than that of jogging.