The Pilates reformer consists of a flat, cushioned, moving carriage with shoulder blocks for comfort and stability, which you’ll definitely need during certain exercises.
It’s this set of springs underneath the front platform that makes reformer Pilates what it is, since changing them makes the carriage and strap resistance lighter or heavier. The springs are typically color-coded to differentiate their resistance, and you can have one or multiple springs attached at a time.It might seem like the lighter the resistance, the easier the exercise.