Seeing a workout with a padlock symbol, like this? 

This means the workout is part of a new program, and hasn't been released yet. 

Programs usually have around 30 to 50 workouts. When Caroline launches a brand new program, she unlocks each workout of that program one day at a time (excluding rest days). This is so that the CGX community can work through the new program together. An unreleased workout will have a padlock symbol to show that it hasn't been dropped yet. 

Why wasn't a workout unlocked today?

Every Thursday and Saturday is a rest day in Caroline's programs, so new workouts won't be unlocked on those days. On non-rest days, workouts are dropped at midnight UK time.

Once a workout has been unlocked, will it be locked again?

Nope! When a workout is released, it will be available on CGX forever. 

Does this have anything to do with my subscription?

No, not at all! Your subscription gives you access to every program and workout on CGX. Locked workouts are only locked because they're part of a new program that's still being released day by day.