(CNN) – Can’t be in the gym for hours on end? Don’t have enough time to attend that 90-minute cycling class? No worries.


Shorter classes, like 30 – 40 minutes, are the trend. It started with higher intensity interval training. Also called hiit.


Those upbeat classes that get your blood pumping can also burn calories fast. It’s perfect for people with busy schedules. And because these short classes can be more accessible, you can take more than one.


Now, boutique workout studios and gym chains are popping up around the country. Even classes, like pilates and yoga, are shortening their sessions. So to maximize your workouts, and burn calories, try interval training.


Alternating high intensity cardio workouts with moderate intensity workouts can make you sweat and boost your fitness level.


Plan your workouts. That way you know what you’re going to do without wasting time. And take shorter breaks between exercises. You’ll move through your routine faster and get out of the gym sooner.

Copyright 2016 CNN