Motivation is always a limiting factor. I have a hard time exercising by itself. I exercise more frequently and longer if I watch TV or a movie while I exercise. Because I find commercials break the flow TV is usually limited to PBS. Movies tend toward action, comedy, and history documentaries. If I get a roll going with a good show I can work it hard for a long time without really noticing.

A friend tells me that I will get better results if I practice exercise as a 'conscious process'. The idea being that focusing attention on the parts being worked causes the body to work harder and get better results. I figure this is mostly nonsense. My body doesn't seem to need conscious supervision to know what to do. Besides, if I have to focus on every move I'm going to get bored and lose motivation.

As an additional benefit I get to catch up on all those movies and shows I've missed.