Slow and Easy
Speaking specifically to the bodybuilders, you have to ask yourself the following:
If my primary goal is maximal muscle, do I want to be performing a high volume of an entirely conflicting activity?
Please tell me you didn’t answer yes to this. This isn’t to dissuade people from doing cardio. If you like cardio, and I know some people that do, by all means do as much as you want. But be cognizant that it may be a conflicting factor that you have to account for if you want to get as big and lean as possible.
If, however, you’re going to do cardio, it’d be best to do something that won’t conflict with your goals and that’s easy to recover from, namely, easy walking. So, if you’re doing the incline walks on the treadmill, you’re probably doing something right. Just keep it as short as necessary.
However, if you’re insistent on stair stepping for an hour to “striate the glutes,” or walking on an incline for two hours as contest prep, consider the following:
You have to take the Specific Adaptation to Imposed Demands (SAID) principle into account.
If you’re dieting for a show and your lifting volume goes down but your cardio goes up, what’s the primary stimulus your body is going to need to adapt to? The cardio. Now how does one become more efficient at slow, aerobic cardio? By decreasing overall energy output, which means burning fewer calories to do the same activity.
So how do we increase energetic/caloric output? We get rid of the most metabolically expensive tissue we have that’s taking up those calories, which means our muscle.