Asked by: Glenn Thomas, by email
Running outdoors requires a little extra energy because you’re moving through the air and this creates drag. But the difference is insignificant unless you’re running quite fast. If you can do a mile (1.6km) in seven minutes or less, which is a speed of 8.5mph (13.7km/h), then the difference is about 1 per cent. Studies have shown that running a mile uses about 100 calories, so you’ll save just a single calorie if you run that mile on a treadmill. Or you can just set the treadmill at a 1 per cent incline to compensate.
Luis trained as a zoologist, but now works as a science and technology educator. In his spare time he builds 3D-printed robots, in the hope that he will be spared when the revolution inevitably comes.