Circuit training involves quickly rotating through a series of exercises targeting different areas of the body. You can do it at the gym, at home, or during an exercise class. Share on Pinterest Getty ...

If you only have 15 minutes to sweat, it's easy to skip out on a workout. I mean, how much can you really accomplish in 15 minutes, right? Umm, a lot, actually—if you spend them wisely. That's the ...