Celeb-Worthy Arm Workout

The summer may be winding down, but it's never the wrong time to get your arms in warm-weather shape. To get buff arms, try this series from celebrity trainer Harley Pasternak, whose clients include Lady Gaga, Jennifer Hudson, Kanye West and Rihanna. Start with a cardio warmup (about five minutes), then do three sets of each exercise, completing 20-25 reps in each set. Remember to add more weight or reps each week.

The Moves

1. Dumbbell Extension: Lie on your back with arms extended up toward the ceiling with dumbbells in your hands. Slowly lower them, bending your elbows, down to your ears, says Pasternak.

2. Triceps Extension: Sit on a chair or a bench, arms overhead, cup the top head of a dumbbell and create a "V" with your arms. Lower the dumbbell behind your head down. "Make sure to use both arms at once," he advises.

3. Hammer Dumbbell Bicep Curl: Hold a pair of dumbbells facing forward, with your palms facing toward your body. Bring the dumbbells up toward your shoulders and back down. "Your fists should look like a hammer, which is how it gets the name," he says.