Fitness: The Rihanna 20-Minute Butt Workout

When it comes to weight loss, the scale can be a good measure of progress, particularly if you have a lot of weight to lose. But if you place too much emphasis on your weight and not enough on your body composition (the ratio of fat to lean muscle), you’re only getting half the story. Aim for three sets of 20 to 25 repetitions of each exercise, says Pasternak. And don’t forget to add in 30-45 minutes of cardio at least three times a week. 

Curtsey Lunge: Stand with your feet together, then take a large lunge backward with your left leg, moving your leg diagonally behind you as you lunge. Repeat with your right leg, and continue to rapidly alternate between legs until you finish your set. If you’d like to modify this exercise, try a stationary reverse lunge, continuing to alternate your legs.

Step-Ups: Using a chair or a bench, step up with your left leg, simply bringing your right leg along with you, and then lead with your left leg on the way back down. Do all your reps on the left side, then switch to the right and start again.

Step-Across: Stand to the side of your bench or chair. Step on using your right foot from the right side. Bring your left leg up, and then step down with your right foot on the left side of the bench. Continue alternating sides for 20 to 25 repetitions.