I run 10miles a min of 5x a week now.2 things,
Im curious about the leg pain from walking. What else are you doing that contributes to it?
Second, Brad is a pro bodybuilder, I have the feeling that work ethic being equal, he would build and keep muscle better than 99% of us regardless of what he does for cardio. Humans also evolved for endurance. We are the single animal on the planet that can run any other species to exhaustion and collapse.
Its how we used to hunt in groups. Keep the target in sight and run it down until it collapsed from exhaustion. I believe that bodybuilders worry too much about losing muscle with cardio when endurance feats are quite possibly the main driver for our species dominance on this planet other than our brains.
Ignoring muscle building, we function very well on endurance under restricted calorie intake. Ancient humans had to hunt and gather and expend enormous amounts of energy just to stay alive and our bodies evolved to these conditions.
I think cardio is less detrimental than people think.
I still have much more muscularity than the general pop. Probably helps that I have been lifting consistently going on 30yrs now.
Now that I shed that top layer of fat all I have is a very lean muscular build. Weighed in at 260 this morning. Flat stomach, abs, thick legs,.wide capped shoulders the whole bit.
Without fail each day on my runs I'm asked if I'm training for football or boxing.
Even with this weight loss over the last year, I'm still very strong in all my lifts. Probably stronger