I've been trying to decide myself how much of my workout time to devote to strength and how much to endurance. I am not an expert, but I think this is a pretty complex process. For any movement there are different types of muscle fibers that are recruited. It doesn't take the same type of muscle fibers for a quick movement like kicking a ball that it does to lift something heavy.
I had a problem with an effusion in my knee and was working out at the gym reguarly. My Physical therapist told me to quit doing some exercises that might make it worse and start doing one exercise for the quads seperately rather than both legs together. I was doing 10 reps where I completely maxed out at the 10 th rep. I other words I wouldn't have done 11 reps.
It didn't help. So then I had my quads tested and I had a 60% deficit in the quick movements of the quads in my left knee. The slow/heavy movement was a little different from one leg to the other, but the quick movement was very different in the affected leg. Anyway, I added 30 reps of the same movement, where I maxed out the exercise at 30. (Actually, I was dying by the 30th rep) Within two weeks my effusion went away. The PT told me that when I was working the endurance type exercise, it would help with very quick movements like you use with aerobics, kicking, running ect. Of course, you gain some strenth with this type of exercise, it really is a different kind of strength, strength with relatively quick movements as opposed to heavy lifing. My thighs really kill me after a few miles up a mountain, and that's a perfect example of where endurance training would really help. For any given movement different types of muscle fibers are recruited, but both are always recruited to some extent. So if you pick an endurance workout, it will still help with "strength", but not to the same extent. If you can only do one, it seems to me the strength training is a better complement to say aerobics or running. To maximize a sport, it might be different. A lot of older people have problems just getting out of a chair because of weak muscles. That's a problem with absolute strenth, not endurance. That's just an example of how much our muscles deteriorate over the years without any resistance training. I was thinking of asking Cathe, how much she devotes to differnt types of lifing.