Shape Up For a Happy Halloween! Your Quick Arm Plan - Rocking a Halloween costume that bares your arms? Spend some time shaping and toning your upper body before putting on that festive frock. Incorporate a few rounds of this quick arm-toning circuit into your regular workout routine for results you'll feel in just a few weeks. Grab a pair of five- to eight-pound dumbbells, and get ready to feel the burn big time.