I have heard the same feedback from other users of EMS Active Recovery programs: to achieve a recovery result, one has to perform AR within the first 12 hours, the closer the better. One (traditional) massage therapist actually commented that he obtained better results with EMS-AR than by using his hands. The reason being that hand manipulation cannot effectively reach deep muscle tissue; instead EMS-AR if cranked sufficiently up, can reach deeper muscle fibers.
Perhaps Waldemar’s rationale came out of the reasoning that it’s muscle soreness that creates muscle adaptations. Therefore, still according to the same line of thought, no pain no gain. But mine is only an interpretation.
Can you tell us if, when your muscles are less sore you feel that your muscles have adapted less?