There's not much data on the topic, so opinions are all over the map. A mix of exercises is good for us. Cardio and Lifting – Cardio won’t hugely impact your gains in the short run, and may be beneficial for strength and size in the long run
My gyms have no dedicated body-builders but I notice that strength-oriented people will do an occasional treatmill run or 10 minutes on the Jacob's Ladder. They also tend to be the only people, besides me, who jump rope regularly. (Jumping is great HIIT cardio, and almost fun if you mix up your jumps. Takes a little skill and practice, but that's a cool challenge.)
I also notice that some gym regulars do almost entirely weights, some only take daily calisthenics classes at 6 am (30 people in my classes), and some only do "cardio" on the treadmills, ellipticals, or Stairmaster. To each his or her own.
Because the Maggie's Fitness for Life program is designed for endurance, energy, athleticism, and to stall or reverse the effects of sloth and age (and to look good, too) more than to build intimidating muscle mass, I think general fitness is worth any possible compromise in growth of muscle.
Also, strength and muscle mass are not necessarily equivalents. I know a gal who does deadlift reps at 300 lbs, and does not look "muscular".
That said, no reason not to keep trying to improve one's deads, squats, and benches. Sturdiness.
Addendum: I have little doubt that training for distance running is a problem for weight training. I was just thinking about gym work. Distance work training (for marathons, +) takes a serious toll.
What do our readers think?
