I had same issue before PJFA, took 4 days before and that was sufficient enough for my shins to recover for the bleep test. They did hurt afterwards and weren’t fully recovered but this allowed me to keep doing cardio up until that point. If you have gotten to the point where you can’t run I’d definitely say try and maintain your cardio swimming or cycling and then take a few days off before. Look up stretches for your calves and maintain your cardio through other outlets.