Donning a full suit of motorcycle leathers for your morning bike ride to work is probably overkill, but cyclists can still be subjected to road rash should they fall while wearing less-than-protective gear.
Wearing a fitness monitor will not make you fit. Nor, for that matter, will wanting to get fit make you fit. No, getting fit will make you fit, and you don't necessarily need a fitness tracker or an iWatch or any other wearable to do that. Just sayin'.