If you did not do the workout JOIN planned for you or if you've done something different, you first have to provide feedback on the ride in the 'Pending feedback' section. Once you've done that, you have to provide feedback on the 'Suggested workout' planned by JOIN to indicate you've done something else. This way we make sure that all feedback is accounted for and your plan is updated properly.
In short, provide feedback twice, indicating you have done something different than the 'suggested workout' and then a reason why.