Ab coaster

With an ab coaster, you kneel on a padded carriage and hold fixed handles while your knees travel upward along a curved track. The movement feels guided and smooth, with the frame supporting a consistent path. You still control how far and how quickly you move, and the kneeling position can take a little getting used to.

It is mainly used to train the muscles around your stomach and sides through a curling knee-raise motion. You can practise moving straight ahead, and some models allow you to turn the carriage for angled movements. The handles help steady your upper body, letting you focus on controlled movement rather than balancing freely.

It may suit you if you want a guided way to work your middle and are comfortable kneeling and gripping handles. The machine takes up more floor space than a mat and is not usually easy to store. You can scale the movement by using a shorter, slower travel at first. For a simpler everyday alternative, try controlled knee lifts while holding a sturdy chair.