I'm a 20-year cycling veteran. In my early 20s I was a Cat 3 and felt really strong, generally averaging 25 mph or better in time trials. On training rides I could hold 18-20 mph for hours on end. The sky seemed the limit.
Today I'm 34 and now average 13-15 mph on rides. Other guys my age have 95% of the power they had a decade ago, while I have about 65%. I simply can't push. The biggest problem is acute weakness/exhaustion that has developed in my left leg, centered around the hamstring but generally affecting the whole leg. My left foot gets a bit numb when I ride. It feels like a circulation issue, but no massage therapist has been able to penetrate the problem, nor is rolfing much of a help (so far).
The strange part is that ever since I can remember, I've been wearing out the right side of every saddle I've ridden. I ride a Brooks now and it's totally caved in on the right side. More than one doctor told me I don't have a leg length problem, so I haven't pursued that theory. Some people say weight train, some say stretch, but those things just increase the exhaustion.
Has anybody else had this problem? I'm clueless, and frustrated. My best cycling years are being wasted because of this. I feel 64, not 34.