frankly, I often don't have the enthusiasm and energy. But most of the time I spend sitting on my duff, I regret.

I always feel better in general when i get out regularly. I try to keep my rides short to minimize the impact on my prostate -- starting with 30-45 minutes of gentle road, and working up to whatever feels like my reasonable maximum.

As a former professional cyclist, I can manage to squeeze in a decent number of miles, but I never really keep an exact count these days. The time, and the aerobic calorie-pushing, is what really counts.