### website Translator

topics

site search facility

# Energy Expenditure

For every physical activity, the body requires energy and the amount depends on the duration and type of activity. Energy is measured in calories and is obtained from the body stores or the food we eat. This article looks at the energy expenditure for walking and running.

### Walking

A linear relationship exists at walking speeds of 3 to 5 km/hr of oxygen consumption but at faster speeds oxygen consumption rises making walking less economical.

Body mass can be used to predict energy expenditure with reasonable accuracy at walking speeds of 2 to 4 mph (3.2 to 6.4 km/hr). The following table details the amount of calories you will burn per minute for ranges of body mass (weight) and speed when you walk on a firm level surface (McArdle 2000)[1]

 Speed Body Mass Kg 36 45 54 64 73 82 91 mph km/hr Lb 80 100 120 140 160 180 200 2.0 3.22 1.9 2.2 2.6 2.9 3.2 3.5 3.8 2.5 4.02 2.3 2.7 3.1 3.5 3.8 4.2 4.5 3.0 4.83 2.7 3.1 3.6 4.0 4.4 4.8 5.3 3.5 5.63 3.1 3.6 4.2 4.6 5.0 5.4 6.1 4.0 6.44 3.5 4.1 4.7 5.2 5.8 6.4 7.0

If your body mass is 64 kg and you walk at a speed of 5.63 km/hr then you will burn approximately 4.6 Calories/minute - if you walk for one hour you will burn 60 × 4.6 = 276 Calories

### Running

 When running at identical speeds, a trained distance runner runs at a lower percentage of their aerobic capacity than an untrained athlete does, even though the oxygen uptake during the run will be similar for both athletes. The demarcation between running and jogging depends on the individual's level of fitness. Independent of fitness it becomes far more economical from an energy viewpoint to change from walking to running when your speed exceeds 8km/hr (5mph). Above 8km/hr the oxygen intake for a walker exceeds the oxygen intake of a runner. At 10km/hr the walker's oxygen (O2) uptake is 40 ml/kg/min compared to 35 ml/kg/min for the runner. Diagram Reference: (McArdle 2000a) [2]

Body mass can be used to predict energy expenditure with reasonable accuracy when running on a firm level surface (road, track or grass). The amount of calories required to run 1 km equals your weight in kg (a runner of 78 kg will burn 78 Calories/km).

One litre of oxygen equals five calories so our 78kg runner utilises 15.6 litres of oxygen per kilometre.

The following table details the amount of calories you will burn per minute for ranges of body mass (weight) and speed when you run on a firm level surface (McArdle 2000b)[3].

 Speed Body Mass (Kg) km/hr 55 65 75 85 95 8 7.1 8.3 9.4 10.7 11.8 9 8.1 9.8 11.0 12.6 14.4 10 9.1 10.8 12.2 13.6 15.3 11 10.2 11.8 13.1 14.7 16.6 12 11.2 12.8 14.1 15.6 17.6 13 12.1 13.8 15.0 17.0 18.9 14 13.3 15.0 16.1 17.9 19.9 15 14.3 15.9 17.0 18.8 20.8 16 15.4 17.0 18.1 19.9 21.9

### How Exercises Compare

The following table contains the approximate caloric expenditure in a 30 minute period of exercise for a person weighing 68kg for various exercises and intensity of work. Add 10% for every 7kg over 68kg and deduct 10% for every 7kg under 68kg

 Exercise Intensity Calories/½ hour Aerobics Light 120 Moderate 200 Vigorous 300 Walking 4 km/hr 105 7 km/hr 200 10 km/hr 370 Running 9 km/hr 320 10 km/hr 350 12 km/hr 430 16 km/hr 550 Cycling 9 km/hr 120 16 km/hr 220 21 km/hr 320 Swimming 25 metres/min 165 40 metres/min 240 50 metres/min 345 Rowing Light 200 Vigorous 420

### Calorie Calculator

Enter the exercise & intensity, duration, your weight and then select the "Calculate" button for an analysis of the amount of calories expended.

 Exercise Aerobics - light Aerobics - Moderate Aerobics - Vigorous Cycling - 9 km/hr Cycling - 16 km/hr Cycling - 21 km/hr Rowing - light Rowing - Moderate Rowing - Vigorous Running - 9 km/hr Running - 10 km/hr Running - 12 km/hr Running - 16 km/hr Swimming - 25 m/min Swimming - 40 m/min Swimming - 50 m/min Walking - 4 km/hr Walking - 7 km/hr Walking - 10 km/hr Duration minutes Weight kg Energy expenditure Calories

### References

1. McARDLE, W.D. et al. (2000) Energy expenditure at rest and during physical activity. In: McARDLE, W.D. et al., 2nd ed. Essentials of Exercise Physiology, USA: Lippincott Williams and Wilkins, p. 170
2. McARDLE, W.D. et al. (2000a) Energy expenditure at rest and during physical activity. In: McARDLE, W.D. et al., 2nd ed. Essentials of Exercise Physiology, USA: Lippincott Williams and Wilkins, p. 169
3. McARDLE, W.D. et al. (2000b) Energy expenditure at rest and during physical activity. In: McARDLE, W.D. et al., 2nd ed. Essentials of Exercise Physiology, USA: Lippincott Williams and Wilkins, p. 171

### Related References

The following references provide additional information on this topic:

• BOUCHARD, C. et al. (1983) A method to assess energy expenditure in children and adults. The American Journal of Clinical Nutrition, 37 (3), p. 461-467
• MIFFLIN, M. D. et al. (1990) A new predictive equation for resting energy expenditure in healthy individuals. The American journal of clinical nutrition, 51 (2), p. 241-247