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]

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 (5 mph). Above 8km/hr the oxygen intake for a walker exceeds the oxygen intake of a runner. At 10km 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].

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

Free Calculator

• Energy Expenditure Calculator - a free Microsoft Excel spreadsheet that you can download and use on your computer.

Referenced Material

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

Page Reference

The reference for this page is:

• MACKENZIE, B. (2002) Energy Expenditure [WWW] Available from: http://www.brianmac.co.uk/energyexp.htm [Accessed

Associated Pages

The following Sports Coach pages should be read in conjunction with this page:

• Articles on Physiology
• Blood Pressure
• Body Type
• Energy Pathways
• Heart Rate Training Zones
• Ideal Weight
• Maximum Heart Rate
• Movement Analysis
• Muscle Types
• Physiology - Cardiovascular System
• VO2 max
• vVO2max