When it comes to time-effective workouts, high-intensity interval training (HIIT) is one of the best choices: it revs up your heart rate and works your muscles in short, intense intervals, and you can get in a full workout in 30 minutes or less. HIIT workouts on YouTube are even more efficient. Skip the gym drive, throw on a sports bra and some shoes, grab some dumbbells, and get going. We pulled our favorite full-body YouTube HIIT workouts to make it even easier for you to get sweating while saving time (and money). Happy HIIT-ing!