Zwift (2015)

For anyone who owns a bike, Zwift will push you harder and for longer than anything else here, because the resistance is real and the only limit is your own legs. Group rides, events and races are all included with a subscription, so there is always someone to chase or a structured session to follow. It is also the biggest commitment: you need your own bike, a smart trainer to mount it on and a monthly or annual membership, though the monthly plan starts with a 14-day free trial. It runs on a computer, tablet or phone rather than a console. Space: the footprint of a bike, plus room for the fan you will soon want.