Best Damn Cardio for Natural

I read your article about the best damn cardio for natural. I like to go walk, but i want to try the conditioning thing with the prowler. 6 sets of 1 min with 2 to 3 minutes of rest.

if i dont it with 2 mins rest it takes 20 mins and with the 3 mins rest 24 mins. I know that i won’t be able to recover well doing a big workout after that. So i have to cut the workout for a low volume approach maybe 20-30 mins. Do you have something in mind ? of any suggestion.

i can’t train more than 4 days a week, im working day/night shift and doing 50 hours +. maybe that’s why i dont tolere volume too much.

i thought of doing your best damn workout #1 choosing 4 days and adding prowler before the workout, or your busy people workout ( 20 mins muscles builder )

thanks