If you want to adjust your program start date, follow these steps:
Open the workout programs
Tap Workouts from the bottom menu, then select the Programs section.
Open your active program
Find the program you’re currently following. It should be marked as Active. Tap the program to open it.
Update your schedule
On the program page, tap Update Schedule at the bottom of the screen.
Choose your new start date and program day
Select the date you want the program schedule to begin from.
Note: If you want to continue from a specific day instead of restarting from Day 1, tap the edit icon beside Start from Day 1 and choose the program day you want to begin with. When everything is set, tap Add to Schedule.
Your workout program will now be updated based on the new start date.