[julirama723]

I think if it's just the case of exercise, you won't have to worry. However, if you're training for the IronMan or something, then I'd worry about bulking up or having larger thighs.

When I do the bike, I usually do 1/1, 2/1, or 3/1 interval training using resistance as my variable. Each bike is different, but usually I keep 6 or 8 as my "recovery" resistance, and anywhere from 12-18 as my harder interval. If I'm doing 3/1 intervals (3 minutes at one resistance, 1 minute at another) I might do 3 minutes at 8 and 1 minute at 18. Or perhaps 3 minutes at 12 and 1 minute at 6.

Another thing I like to do on the bike is 8/12 second intervals. Sounds crazy, but I've read a few places that 8 seconds of faster, intense activity followed by 12 seconds of a normal recovery speed is great way to burn fat. It makes sense, you're basically short-tripping your body, much like you would a car. Every time you start your car (or begin pedaling with intensity and speed for those 8 seconds), it uses more "gas" than if you were to just keep it running (or pedaling at one speed or one resistance).