Which is better – running indoors or out?

Gym rats prefer the consistency and convenience of treadmills, while others head outdoors no matter the weather. But who is right?

Some say outside wind resistance uses more energy, but researchers found that setting a treadmill to a 1% gradient was enough to compensate for this effect. Running on varying terrain provides a workout for a greater range of muscles. Outdoor hazards such as air pollution, dog mess and security could tilt the balance back towards the gym, but treadmills put athletes at greater risk of injuries related to repetitive movements.

Studies show outdoor workouts generate greater feelings of well-being. Researchers at the University of Exeter who reviewed 11 previous studies in 2011found people felt more revitalised, energetic and positively engaged, and less tension, confusion, anger and depression, when they exercised outdoors. “There seem to be psychological benefits from exercising outdoors,” says Dr Costello. “However, when it’s dark and cold, it can be challenging to get out. So, as exercise physiologists, we’re slow to say one is better than the other.”