"Don't You Get Tired?"

When I go to the gym on my cross-training days, I normally park myself on a stationary bike and read, read, read things on my iPhone for a good 45 or more minutes.  It's a good way to pass the time, and I can catch up on great articles linked on Twitter, email friends, check the news, etc.  Because it's a cross-train day doesn't mean I take it easy.  (You wouldn't have believed me anyway if I said that's what I did at the gym, would you?!)  My RPMs normally start out at about 85-90 and then go up from there.  It's not like a spin class, but I normally get into a groove around 100-105 RPMs.  Toward the end, it's not unusual for that to go up to 110-115.  The kind of cool thing is that despite this being faster than probably most of Planet Fitness' clientele's cycling, it really isn't too much of a workout (cardio-wise) for me; I'm certainly not huffing & puffing even after 50-55 minutes.  (Hmmmm...does that mean I should work harder?!)  

On Tuesday, this older gentleman (probably in his 70s) comes up to me while I'm trucking along on the bike and asks me, "Don't you get tired?"  He goes on to explain that he was watching me (uhhhh, kind of creepy) and wondering how I could keep going & going.  My short answer was to tell him that I ran for 3 and a half hours on Saturday, so this was pretty easy for me.  (Was that too uppity of a response?)  He was very nice, so I guess my answer didn't come across as snooty (and I certainly didn't intend for it to be snarky).  I can't remember what his parting words were, but they were pleasant.  Something along the lines of "it's very impressive" and "keep up the good work."