Which piece of equipment is commonly used in Pilates for resistance training?

The Reformer is a central piece of equipment in Pilates that facilitates resistance training through adjustable spring tension. This equipment is designed to help practitioners perform a variety of exercises that can be modified for different levels of resistance, catering to both beginners and advanced users. The Reformer supports the body while allowing for a range of movements that enhance strength, flexibility, and coordination. It features a sliding carriage, adjustable springs, and a variety of attachments which make it a versatile tool in Pilates practice.

While the Magic Circle is also used to add resistance and enhance certain exercises, it does not provide the same comprehensive range of resistance training as the Reformer. The Ballet Barre is mainly utilized in dance and physical conditioning rather than specifically for traditional Pilates exercises. Lastly, the Wunda Chair is another Pilates apparatus useful for strength training, but it does not have the same widespread application for resistance training as the Reformer, making the Reformer the most commonly used equipment for this purpose in Pilates.