This Jennifer Lopez-approved cardio workout is one of the most-intense ways to get your heart pumping

Whether its on screen, on stage, or IRL, Jennifer Lopez is never afraid to push things to her limit. So, it should come as so surprise, that she's been known to do one of the most-intense forms of cardio: stair sprints. Here's why they're effective, plus how to do them yourself.

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Photo: Getty Images/Jason Merritt

16 Upper Glutes Exercises Personal Trainers Swear By for a Stronger Butt

Why your upper glutes deserve more love, and the best exercises to strengthen them.

woman doing an upper glutes exercise with an exercise band.