Dumbbells form the core of a home gym. They are essential tools for every fitness enthusiast to improve strength and form. Buying dumbbells as a set is a great idea as it gives you more training options. And if you buy a set, getting a rack along with it is highly advisable. Having massive free-weights strewn across your floor will look messy and can even be dangerous. A rack will save you a lot of trouble and space as well.