Winter running athlete woman on cold run jogging fast with speed

One of the great things about working with an online personal trainer is that you can work your workouts to your own schedule, without having to worry about booking in a face-to-face appointment at the gym.

While the gym might be one of our favourite spots to be, we don't know how we'd feel if they dialled down the thermostat to as low as 6 degrees, as one recently launched gym in the US has.

According to CNBC, Brrrn gym has opened with an unique selling point – it's the world's first 'cold-temperature fitness studio'.

According to co-owner Johnny Adamic, the cold temperature helps to burn fat quicker: “When you exercise in cooler temperatures, you optimize the fitness experience, because you burn more calories than in ambient or hot - cooler temperatures provide the optimal temperature for working out," he says.

At present, it offers just three classes: HIT, a core class and a yoga-based class, all of which take place at slightly different, though still low, temperatures. According to these gym entrepreneurs, the typical gym operates at around 22 degrees, so it's a big drop.

The idea is backed up by scientific evidence, according to CNBC, though it's undoubtedly a bit of a novelty to stand apart in the crowded New York gym scene. And it's worked, as the gym has grown faster than the founders have expected.

The big question is what to wear? Take a look at a few snapshots of Brrrn and while you'll see traditional gym shorts and t-shirts, there are also a few clients in woolly hats too.