It would be great if we could all spend a full hour in the gym each day. Then again, it would be great if our bosses would stop with the last-minute assignments, if there was no rush-hour traffic, and if you didn't just waste 15 minutes of your potential gym time watching YouTube fitness fail videos.
The American Heart Association and the U.S. Department of Health and Human Services both recommend Americans get at least 30 minutes of exercise five times a week. But the truth is that just 20 minutes can be just as good — especially if you really turn up the intensity.
"If you're going to gain any recognizable training benefit, short workouts have to be hard workouts, and really short workouts have to be really hard," says Chad Timmerman, a USA Cycling Level 1 certified coach with more than 25 years of racing experience.
Get ready to hurt. These seven 20-minute workouts will burn calories, build muscle, and eliminate any excuses about being too busy to get in shape.