anybody know or have heard from someone if it's legit?

You're asking if working out is legit?

Depends on your goals.
Will it help your cardio endurance and potentially lean you out? - yes if you do it well

It's also just a nice chnage of pace from lifting.
Variety is good.

If you're asking if it does what it says it does- answer: sure, yes.

Variety?!

#MuscleConfusion