Sandra is one of the world's best-known fitness models. You’ll get it when you see her videos and photos. Sandra Prikker Kas (26) is an online fitness coach, model, social media influencer, business owner and a world traveller! Kaz van der Waard Eike (29) is an official Body & Fit athlete and has established quite a following in a very short space of time. Eike Wiemken