Take more rest/recovery days. Doesn't need to be zero activity. On rest days I stretch and do light calisthenics. Nothing extreme -- range of motion, shadow boxing for upper body, massage, rollers on muscles I can reach.
Last week I overdid a new-to-me training session on the indoor bike trainer. An hour at low cadence, 50-60 rpm mashing the top gear, rather than my usual spinning. Strained some muscles in odd places -- the top of the foot, front of the lower leg. Still hurts several days later.
Tried an easy 12 mile ride Sunday after taking a week off (other than easy indoor trainer sessions), but it was too cold and I felt worse afterward. I'll try a moderate effort group ride Wednesday, probably around 40 miles by the time I get home. But I'm gonna avoid pushing too hard until the weather warms up. I find myself tensing up in the cold, which probably leads to poor ergonomics and minor injuries.
Then I got a call from my endocrinologist today telling me my bone density scan showed some bone loss. Side effect of my dysfunctional thyroid. So I need to avoid extreme strain until that improves and I take the stupid supplements, presumably something like alendronate. Family history of osteoporosis, stress fractures, etc., but so far all of my fractures were due to trauma, fairly hard impacts, not just exercise induced strain. So far.
Getting old sucks. Took awhile for me to get the message than I can't work out 5-6 days a week anymore. I've cut back on the muscle building stuff to once a week for now, rather than 2-3 times a week. So far, so good. I just need to discipline myself to apply the same thing to bike rides.
So, back to my usual preference for spinning. Suits me, I'm more comfortable around 80-90 rpm anyway. If I do the big gear mashing again after a couple of weeks recovery I'll limit it to 15 minutes or so, and add some careful squats, lunges, etc.
I'm older than most of the folks in the local fast club's B-group, and I've noticed the 50something folks don't usually work out on days other than the three main weekly group rides. Probably a good practice. Their group rides usually wring me out, so if I rode with them more often I really wouldn't need to do any other rides.