In multi-session trainings, it is often suggested or sometimes even required to meet with other participants to exercise between the official trainings. Even in cases where that's not officially part of the trainings, I want to encourage you to speak up and announce you're willing to provide your body to others for their training (who may be there for a professional career) -- in fact it's not like you're "asking for a free massage", you are offering a very valuable contribution, since you can give them feedback based on what you both learned in class, which is something other people they know will not be able to do. Also, it takes a bit of courage to ask friends, especially at the beginning, and hesitancy to touch friends in new ways; there's something about being in class together that makes it easier to accept touching the other; it's a 'professional' relationship.