>>964922Riding 'clipped-in' gives you better stability on the pedals, especially when used with a stiff-soled shoe. For the purpose of fit, this stability and also the consistency with which it places your feet in relation to the pedal, this allows you to access your core muscles more easily. In turn, your arms and upper body muscles take up less of the work for supporting your weight and are allowed to facilitate deep breathing.
Just my 2c
