I don't have time to go to the gym every day and I sure as hell don't have time to go out and run as much as I want to. Luckily, there are ways to fit in some solid cardio even with a packed schedule, and I wanted to share my favorite approach. Men's Fitness gives you two options, but I'm going to focus on one.
AMRAP = As Many Reps As Possible
Only have five minutes to fit in a workout but still want that cardio for the day? This approach is your best bet for getting your blood pumping in as little time as possible. Pick one exercise (seriously, any move) and do it for five minutes straight only resting when you really need it.
If you're feeling energetic, do a faster move (like jump rope or high knees) and if you're feeling drained just do some sit ups or basic boxing moves.
Since the large, powerful muscles in your lower body burn the most calories when you work them try something like step-ups for five minutes. Sure, it might sound lame, but compare imagine that you were climbing stadium steps for 5 minutes straight. You’re going to feel that.
If you really want to feel the burn, try and do five minutes of burpees. Your heart rate will go through the roof right away.