Thing is doing 'hard cardio' to the point of cns fatigue is a different beast to 'easy cardio' which by implication is nowhere near any state of fatigue.
So seriously thrashing yourself to bits interferes with strength gains due to in part the recovery resources being compromised after that thrashing.
Absolutely. Get that.
For easy less demanding cardio though? No conflict, just less, manageable and recoverable? Zone 1 and 2 stuff, just 30-60 minutes or so.
Can't see how walking or easy aerobic anything would be a issue. Certainly to conserve energy, lift heavy, eat loads and sit on arse to maximise growth and to get big.....if that's the goal, then yeah ditch other activity.
As someone who keeps a close eye on cns fatigue with sprinting...I limit strength training for recovery. I do not mix strength. But roadwork, moderate strength training followed by easy run/walk? Totally different, no?