Few pieces of kit turn a spare corner of a flat into a conditioning station as quickly as a loaded ball. Slam balls are packed with sand inside a thick rubber shell that kills the rebound, so the ball lands and stays put rather than bouncing back at your shins. That dead stop is the whole point, because it lets you throw at full effort without having to catch anything on the way up.

Medicine balls behave differently. They hold a firmer shape, offer some bounce, and suit controlled rotational work, wall targets, partner passes, and loaded sit ups. Gymsportz carries both formats from $28, including Bullz regular and double-handle models, the Bullz slam ball, and the Pivot PM165 wall ball.

Nothing about ball training is complicated, which is a large part of the appeal. What separates a productive session from a sore lower back comes down to load selection and body position at the moment of release.

Pick your load first
Most people starting out do well with 4kg to 8kg for throwing work and 6kg to 10kg for slams, since technique breaks down long before the muscles give out.

Set up on a protected surface
Rubber matting under the landing zone absorbs noise and protects tiles, which is the difference between training freely and hearing from the neighbours downstairs.

Slam from a braced hinge
Lift the ball overhead, brace the trunk, then drive it down through the hips instead of yanking with the arms.

Use the wall ball for volume
A target line at roughly 2.7m turns a squat into a full-body conditioning set, and the padded shell is built for repeated wall contact.

Save the double-handle model for carries, sit-up passes, Russian twists, and overhead holds, where the grips let you control the ball away from the body.

A ball earns its place by covering ground heavier equipment leaves alone. It sits somewhere between a conditioning kit and a strength kit, which is why coaches keep one in the corner even when the rack is fully stocked.

Rubber quality decides whether a ball lasts five years or five months, and it is close to impossible to judge from a product photograph. A supplier who has handled the stock, dropped it, and taken the returns is the shortcut around that problem.