Numerous activities can be done on das.Brett to train your stomach, back, glutes and legs as you would at the gym. To really turn up the heat on your workout, do a trampoline-style bounce on the edges while exercising! No other "Rocking Board" on the market is flexible enough to bounce like das.Brett!Discover our diverse training program that includes warm up, cardio, stamina, and stretching exercises — all included in an illustrated manual, included with every purchase of das .Brett!