Each day that you have a workout planned, you will be sent a short training reminder email. It's just to give you a quick overview of what you've got coming up and help you prepare.
If you would rather not recieve those emails you can disable them by updating your user profile online or in the iPhone app. Your preferences will be updated and within 24 hours you should stop receiving emails
Online - Simply untick the box and hit Save:
In-App - Go to Settings > Support and toggle the switch to OFF: