I've been told that you don't want to do extreme leg cardio without a days rest inbetween. You can do resistance workouts(ie weight lifting) on the days inbetween your cardio days. But that you need give whatever muscle that you worked a day off. So you could do a good bike ride one day, do some leg workouts in the gym the next, and then do swimming the third day.
So basically you can work the same muscle day after day, but it needs to be in a different way.
At least thats what I was told. It made sense though, after that 17 mile ride that we did where my legs cramped up and gave out at the very end. The very next day I went and did weight training with my legs( heavy squats) and they were feeling great. I didn't expect that.
Shit last week, I did squats Monday, Deadlifts Wednesday, mountain bike ride Friday, Squats Saturday, and another mountain bike ride Sunday, and then squats again Monday! Finally back to 225ibs on the squats though!
So does anyone ever hit the gym? Weight training?