Question from J. Schardt: Is it orthopaedically and biomechanically harmful to ride on a training roller every day, as the pedalling motion is less rounded than on the road? I keep reading that it is better to buy a spinning bike, as this ensures a rounder pedalling motion. Is that true?
Answer from Dr Stapelfeldt (Bike lab):
In principle, excessive or incorrect loads can damage the musculoskeletal system - whether on the road, roller trainer or spinning bike. The risk is no higher with indoor training than with road training, even if different forces act on muscles, tendons, ligaments and bones. This is due to the fact that the bike, at least on a "fixed roller", cannot tip to one side; in addition, depending on the roller model, the flywheel mass is lower than outdoors, where the weight of the rider and bike form the flywheel mass. On a spinning bike, the heavy front wheel takes on this task, with the cranks always turning due to the lack of a freewheel. This means that you remain passive in the lifting phase, even if the movement feels smoother. The flexor muscles, which actively pull the leg upwards, are trained less, which can lead to an unrounded pedalling stroke. In this respect, roller training is even closer to freewheeling than spinning.
