In less than 20 minutes, you can sculpt your arms and abs with this upper body dumbbell workout, all while getting your heart ...

Follow along with trainers Jacqueline Kasen and Gerren Liles in the workout video above, or if you're ready to HIIT it solo, read the instructions below for a self-guided workout.

Not only is circuit training a great substitute for ordinary cardio, it also helps tone your ... Make sure you include upper body (chest, arms, back) exercises as well as those that target your ...