do I need to wear anything specific?

you will probably be most comfortable wearing loose fitting or stretchy clothes, I suggest trousers or shorts plus a top. 

Definitely avoid anything that is tight around your mid-riff as this can impede natural breathing and movement.

 

The rooms have heating but it is always advisable to bring a jumper and/or blanket/shawl for those parts of the session where you are at rest and needing extra layers.

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