9 Efficient Cardio Planks To Work Your Core *and* Spike Your Heart Rate

Cardio planks will work your core *and* spike your heart rate. Oh, and they'll make you extra sweaty, too. Here are the best ones to try.

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Photo: <a href="http://www.stocksy.com" target="_blank" rel="noopener noreferrer">Stocksy</a>/Guille Faingold

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.