1. Hold a 3- to 8-pound dumbbell in each hand and lie faceup on bench (or on a mat on the floor) with knees bent, feet flat on bench. With arms out at sides, bend elbows so upper arms are at shoulder level and palms are facing forward.
2. Contract chest and press weights up so that left wrist crosses over right. Lower to start. On next rep, cross right wrist over left. Continue alternating crisscrosses for 8 to 16 reps.