Treadmill vs street running – that is the question. And if you want to know the answer to which one is better for you, read on as it’s not as simple a question as it might seem.

The weather seems like an obvious place to start…

It does, and as you’d expect the treadmill wins this round due to have a gym roof that stops snow, rain or wind. It’s not a walkover, however, as street running features a greater intake of fresh air and more wind resistance, which can lead to greater energy expenditure.

So does street running get you fitter?

A study published in the Journal of Sports Science found that if you consistently knock out miles in eight minutes or less, the answer is yes. But before you street-runners reach peak smugness, the same study also found a) that this difference could be negated by setting the treadmill to a 1% incline and b) that there was no difference between the amount of energy runners expended outside or on a treadmill, if they ran at a speed of 7.5mph or slower.

What about injuries – which is less dangerous?

Again, it’s complicated. Treadmills tend to be better for people coming back from an injury. “The surface offers a certain amount of compliance or springiness, which helps to reduce the force that travels through your joints and other injury sensitive areas of the body,” says physical rehabilitation expert Casey Kerrigan.

And how about street running?

It’s less kind on your joints, but running outside makes you less injury-prone overall. Running on uneven terrain gets your ankles used to a variety of landings. If you only run on treadmills, you get used to a very steady stride, so even a small misstep can result in an injury.

I don’t want to go outside. Can I train for a street-running event solely on a treadmill?

You could, but it’s inadvisable. “Treadmills are good for speed-improving drills,” says Men’s Fitness’ expert personal-trainer Rob Sulaver. “But the closer you get to an event, the more important it is for your training to mimic the conditions of the race. Try to get at least one or two runs a week outside, and increase this number as you approach race day.”

Finally, do I need a different set of shoes for running on a treadmill and running outside?

If you’re running along a rocky trail or up a snowy mountain, then some specialist footwear will be in order. If you’re sticking to British roads, then Runner’s World’s gear expert Jeff Dengate confirms that  “most runners wear the same shoes both inside and out”.