It's important to stay in touch with your clients. Email clients that take classes frequently and reward them. Here is a sample email:
Hi [Client First Name],
You have done a great job keeping up with your training! I've really enjoyed seeing your progress and am looking forward to seeing you in class again soon. Keep up the good work. Join me again for live webcam class at [your Trainerly Profile Page URL].
Thank you and have a wonderful rest of the day!