You may already have a fitness routine that involves a variety of workouts such as cardio, strength training, and yoga. But did you know that incorporating High-Intensity Interval Training (HIIT) into your fitness regimen can help to build muscle and improve muscular endurance, while also strengthening the impact of your other workouts? HIIT workouts generally last about 30 minutes and combine intervals of more intense workouts with periods of low-intensity recovery, making for a challenging workout that has a variety of fitness benefits. Below are some reasons to add HIIT to your regular fitness program.