The debate: treadmill vs outdoor running

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  • One burns more calories but may cause more injuries

    There are two types of runner – those who like treadmills and those who don’t. But, for producing results, does your running preference really matter?

    Experts seem as divided in their opinions as runners. Studies have shown that indoor running burns about 5 per cent fewer calories than running outdoors, partly because of the lack of wind resistance and partly because the treadmill‘s motorised belt propels you slightly.

    Phil Hayes, of Northumbria University, says that fewer calories are also used while running on harder surfaces. ‘Run on muddy, sandy or grassy ground and your leg muscles need to work harder to push upwards and forwards for each stride,’ he says.

    Dr Sharon Dixon, of the University of Exeter, says that treadmill runners often alter their technique without realising it, sometimes moving more slowly or with shorter strides.

    Such adaptations don’t necessarily mean that you are more likely to be injured. In fact, newcomers to running may well experience fewer problems if they start out on a treadmill, which offers more ‘give’ than concrete or a road surface.

    Stick solely to the treadmill, though, and over time your susceptibility to injury will rise. ‘Running outside exposes your body to the unpredictable,’ Dixon says. ‘There are changes in terrain, undulation and direction that force you to use different muscles all the time. On a treadmill you use the same running style all the time, which means that you are loading the same muscles and body parts that could eventually become prone to stress-related injuries, particularly if your style is not that good in the first place.’

    ‘There are pros and cons to each and it really does boil down to personal choice,’ she says. ‘A lot of people just don’t feel safe running outside when it’s dark or they feel self-conscious about running in the park or down the street. For them, treadmills are a source of security. It’s better to run indoors all the time than to not run at all.’


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