That said, decent dumbbells don’t come cheap, so to save you from doing the heavy lifting this Prime Day, we’ve selected one of the best Prime Day deals out there. The Bowflex SelectTech 552 dumbbells and stand just dropped to $405 in the Prime Day sale, which is a whopping $173 discount. Unlike regular dumbbells, a pair of adjustable dumbbells enable you to turn a lever and increase or decrease the amount of weight, without having to fiddle around adding plates between reps. This means during the downtime in your workout you can actually relax and allow your muscles to recover. Plus, you only need to buy one set of dumbbells, which can get heavier as you get stronger. While the stand isn’t necessarily needed, it does mean you can place your dumbbells back on them, rather than lowering them all the way to the floor, protecting your lower back when you’re lifting heavier weights. The stand also includes straps to secure the weights in place when you’re not using them — helpful if you have kids or pets in the house. If you’re building a home gym, a good set of dumbbells is often preferable to a barbell, as you can easily modify deadlifts and overhead presses to use dumbbells, whereas it’s more difficult to use barbells for bicep curls and rows. Not sure where to start? When testing the Bowflex SelectTech 552 adjustable dumbbells, we were impressed with the compatible BowFlex SelectTech app, which includes dozens of dynamic exercises you can perform with your new dumbbells, along with six targeted workouts, a six-week weight-training program, and a digital journal. It’s a genuinely useful app, and you just can’t argue with the price — free.