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.

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). McArdle (2000)^{[1]} details the number of calories you will burn per minute for ranges of body
mass (weight) and speed when you walk on a firm level surface.

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

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. See McArdle (2000)
^{[1]}
.

Body mass can be used to predict energy expenditure with reasonable accuracy when running on a firm level surface (road, track or grass). The number 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.

McArdle (2000)^{[1]} details the number of calories you will burn
per minute for ranges of body mass (weight) and speed when you run on a firm
level surface

The following table, adapted from McArdle (2000)^{[1]}, 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 |

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

- 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*

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

If you quote information from this page in your work, then the reference for this page is:

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

The following Sports Coach pages provide additional information on this topic:

- Articles on Physiology
- Books 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