Related Tables with Template?

The title may not be accurate, as I may not have this set up optimally, but here goes:

I have a workout DB that allows me to enter workouts (workouts contain exercises), meals (meals contain foods), and schedule the workouts and meals in a schedule table (links a meal or a workout to a schedule record with a date and time).

An image below illustrates the relationships.

Here's where I'm having trouble:

I want to track my progress as far as weights and reps. This means a seperate "Instance" table for the workout items. When I add a workout to the schedule, the workout items instance portal should populate with the exercises in that workout simply by entering a workout ID. However, I don't see that as possible via my design. I have to create new "instance" records, and copy the workout IDs into them. This is not ideal, and I feel like I'm missing something here (there has to be a better way). I know a but about DB design, relationships, etc, but can obviously use some guidance.

Any help is greatly appreciated.