You'll lose roughly 8% musclemass per decade past your thirties (allegedly, no citation given), so it's a good idea to incorporate some gym work in order to maintain lean mass.
In terms of helping your cycling then the conclusion seems to be that riding your bike helps more than time in the gym- although if you are training for short, explosive efforts I would think that gym time would start to help.
You'll lose roughly 8% musclemass per decade past your thirties (allegedly, no citation given), so it's a good idea to incorporate some gym work in order to maintain lean mass.
In terms of helping your cycling then the conclusion seems to be that riding your bike helps more than time in the gym- although if you are training for short, explosive efforts I would think that gym time would start to help.