Grab a set of dumbbells and a resistance band to target your arms and core. Feel the burn as you power through three circuits: the first two with equipment for an upper-body burn, and the last focusing on core strength with just your bodyweight. Expect to sweat through shoulder presses, mountain climbers, bicep curls, and more, with 45 seconds of work followed by 15 seconds of rest.

Equipment: Medium Dumbbells, Resistance Band