Simply tell your clients you do not believe they are completing their workouts if they are not checking-in and encourage them to do this. If they are signing up for online training they most likely have access to a computer or a smart phone on a regular basis, which means there is no excuse for not checking-in for your workouts.
By encouraging client check-ins our clients will become more comfortable with using Skype, Facetime & text message and tracking their workouts will become a habit. Especially if you encourage them to check-in and then share that check-in through their social media, as this will help their friends, colleagues, and families cheer them on through their workout as well as yourself (the trainer). This will increase the feeling of commitment to their goals and their program. Once they start to notice the support system they can create through checking-in and make this a habit, their engagement increases which mean their results improve, turning short-term clients turn into long term clients.
Thank you for your download, we hope you are satisfied with our software.