For fitness enthusiasts who need a little cardio variety, HIIT (or high-intensity interval training) has long been a popular choice. According to a study in Biology of Sport, HIIT — which pairs short ...

Keep scrolling for 21 great high-intensity workout options to try that range from five to 45 minutes and include all different protocols. Note that since HIIT has such a broad definition we used ...

Your boring workout is secretly sabotaging results try HIIT for faster fat loss muscle gains and nighttime metabolic burn.

When you buy through links on our articles, Future and its syndication partners may earn a commission. Credit: Getty Images If you hate running, the good news is it’s not the only way to burn ...

Set up interval training workouts the right way with these expert tips. But instead of putting together a 30-minute, non-stop workout, break up your program into shorter all-out intervals with ...

If you hate running, the good news is it’s not the only way to burn calories and build muscle — HIIT training is a great alternative, especially if you’re short on time. In fact, you’re ...