I notice the same. We're not 20 anymore. I'm a little stiffer, balance is off a little, I have to be more careful. Clipped in on the bike, I feel fine and strong and all that. But that's a very limited physical situation. I also ski Alpine and am still skiing hard a fast, no problems there, but again that's a limited situation. I normally have a rest stop on the bike every 30-50 miles. I take a little break, eat a little something, get water, pee, maybe have a coffee. On really long climbs on a big ride when I'm exhausted I'll sometimes stop for 1-2 minutes every hour, just stand there for a bit. But that's unusual.

In unfamiliar situations, I'm a little dicey.