One on one coaching is intended to solely work with one of our coaches 1-on-1 in for up to a hour and 15 minutes on your fitness program tailored to your goals. Semi-Private you will still be working on your own individualized program with your coach for that session, however there can be up to 4 people to attend within that 1 hour and 15 mins of your training session. So you still get that one on one attention but you share the fun of training with others.