"To make it clearer, at the time he was referring to spinning, which is cycling on a stationairy bike."
I knew she'd remember.
Personally, I think any high intensity cardio is catabolic particularly for the muscle group that is being worked for two reasons.
1) Anything beyond 25% VO2 max intensity, will start using muscle glycogen vs fat only assuming you're in a fasted state. Consumption of any carbohydrate that increases insulin, regardless of exercise intensity will result in a much higher amount of carbohydrate oxidation and far less fat oxidation.
2) If you're performing cardio at an intensity that results in significant physiological aerobic adaptation, then the chronic low repeated stimulation of the muscle is likely going to force it toward or maintain it as a smaller more aerobic fiber. Thus, the harder you perform cardio, the more the working muscles will try and adapt. Marathoner look.
The goal with bodybuilding is to do as little formal cardio as possible and make most of your changes in bodyfat through dietm and low intensity activity (fast walking flat or slower walking incline) . 30 min 3x per week is fine for a general cardio effect, but much more and you'll start heading to the marathoner look vs bodybuilder.
Having said that, is there anyone out there that has tried both and what are your thoughts? What works better for perserving both muscle mass and causing fat loss?
My thoughts anyhow.
W6