If you're short on time or bored of your usual workout routine (more squats, push-ups and planks, anyone?) then this is the session for you.
It's a single dumbbell move, and you only need one dumbbell to do it. This is ideal when you're at a busy gym, although for home workouts, it's still worth investing in a set of the best adjustable dumbbells for flexible training, though fixed-load weights like these Amazon Basics Hex Dumbbells will do the job too.
