If you're like most guys, you probably discount quick workouts as real workouts. You can't possibly burn that many calories, build up muscle, or get any real benefit. Well, that's where you're wrong. More and more studies are unveiling the benefits of short sweat sessions. Not only do they maximize time spent being active throughout the week, they offer a solid changeup from your traditional 45-minute strength-training routines. 

Here are three science-backed ways a 20-minute workout can elevate your health. 

1. Squeeze in a fast gym hit

Super-short workouts aren’t a waste of time, says the UC, San Diego School of Medicine. Even a 20-minute gym session can stimulate your immune system and strengthen your anti-inflammatory defenses—that is, keep you stronger, thinner, and all-around healthier. 

2. Get a better hard-on

Twenty minutes of interval weight training (7-minute warmup; seven 1-minute, high-intensity rounds; 1-minute rests in between) can improve blood-vessel function more than a similar interval cardio session. Better blood flow equals a stronger heart, a longer life, and better, stronger erections, according to research from the University of British Columbia. Yeah, that last one sold us on it, too.

3. Jump-start your heart

Working out on any type of trampoline for 20 minutes burns the same calories as 20 minutes of running at 6 mph or biking at 4 mph. It also aids heart rate and O2 intake, according to the University of Wisconsin-La Crosse.