What does the add set button on the tracking a workout page do?

While performing an exercise sometimes you do more reps than were assigned originally. Really you don't want to lose this information, so we allow you the user to add additional performed sets to a specific exercise. As a side note, adding and then saving additional performed sets to a specific exercise could potentially increase the percent complete for that specific exercise to a value above 100%. For example if 3 sets of 8 at 100lbs were assigned, and 4 sets of 8 at 100lbs were actually performed, the percent complete value would show above 100%.