hhmmmm ... I'd have to disagree slightly here. While the pedaling motion is the same. ie. round and round, there are some marked differences. Firstly the angle at which you sit and pedal is completely different. With the Uni you sit directly over the wheel in a more upright position and forces are directed more downwards, whereas on a bicycle you're sitting more hunched with forces directed slightly forward, ie. centre of the cranks are offset forwards from the saddle. Secondly, because it's a fixie all your control is in the pedals therefore more control of quad and hamstring muscles required at the same time in order to maintain balance. Which then leads to the third thing, balance. The constant corrections to balance will strengthen core muscles which in turn will strengthen lower back muscles. Riding a Uni is a different workout. For me riding a bicycle feels so foreign, and almost wrong mostly due to the pedaling angle and can feel a difference in how muscles are used. agree to disagree then. Its circular movements with your legs. Working 90% the same muscles either way. So the idea of cross is to change the muscle groups and movement a bit to train the other muscles and also strengthen your bone with more impact movements etc. so either way - it depends on what your idea of cross training is. Is it to improve your current main sport - lets say MTBing OR is it to improve muscle movement / flexibility and / or strength to prevent injury from overused muscle groups and repetitive movements ?? That my friend is the question
