Normally my routine revolves around weights days (2-3 muscle groups a workout i.e. ''push'', ''upper'' etc) intermixed with conditioning days in the form of sprints (normally flat, not hill). I'm very pleased with the results I'm getting at the moment- I'm sitting at around 185 and slowly leaning up at the same weight.
HOWEVER, my left quad more or less gave-way about 1/2 way through this last sprint session, and I'm pretty sure I've at the least strained it. I've always been one to need conditioning to keep me lean and ''in shape'', so I'm a little concerned about what I can do until the quad heals... I've never reacted well to long, steady-state cardio so even light jogging isn't an option (low intensinty should be ok for the quad), and when I swam lots I found muscle mass drop off me.
So I'm looking at 'rounds' on the heavy bag as an alternative to sprint conditioning days. Is this form of cardio known to be particularly catabolic, or will it help retain the muscle mass I have, in a similar way to sprints?
I'd really appreciate any help guys, thanks!