The lack of change in PFM activity could be due to a no more than moderate to submaximal PFM activity during SR-WBV, the maintenance of reflexive PFM activity despite PFM fatigue or a compensation of slow red PFM fiber fatigue by an increase of innervation frequency and motor unit recruitment of the fast white fibers. As there is no SR-WBV modality dependent difference regarding PFM activity, the continuous modality is recommended in clinical practice as it is easier to apply and less time consuming.