Experienced exercisers and athletes might find standard interval training to be a bit lackluster for their needs. If this is the case, you'll find in high-intensity interval training (HIIT) a means to build high endurance and stamina for longer bike rides, runs and other strenuous activities. HIIT improves the ways your body burns fat, meaning athletes can work longer before having to tap their carbohydrate stores [source: Jaret]. High-intensity workouts push your body so it has to spend the rest of the day consuming oxygen and energy just to recover. You won't want to do these workouts more than three times a week.
HIIT tends to follow the same basic premise of interval training with one exception: The rate of intense workout should push your heart rate up near its maximum and not let it drop all the way back down to its resting pace during the workout. Still, as with traditional interval training, strenuous exercise followed by a pause helps build muscle faster and more efficiently.
There are several ways to complete a high-intensity workout. One method is a four-minute workout where you train for 20 seconds at your maximum, then rest for 10 seconds, then 20 seconds back on, 10 seconds off -- until you've completed this cycle for eight rounds. You can even change the workout types in this method, moving from your legs to arms to abs in each cycle. Most high-intensity interval training workouts are similar to this one, and you can change and edit your own workout as you see fit.
These high-intensity workouts are a way to quickly lose weight and get cardio fitness into your larger workout regiment without cutting into your time too much.
We've covered the methods and ways interval training works, but we'll take a look at the benefits and downsides of using this workout technique in the next section.