Hello there....such incidences usually occour when you are not accoustmd to the sternous activity u wish to take be it trekking,cycling or sports activity at a competative level.... its bcos of loss of electrolytes in your body due to exhaution u r feet must have felt numb... it is fairly common so dont worry also the twisting was a result of this... i hope the twisting pain has gone... many ladies come to me with similar complaints saying they get similar numbness feeling after sitting in cross legged position for more than an hour...research suggests that a deficiency of Vit B12 and vericose veins have strong co relation with the above condition.... do let me know a few things 1)your height and weight 2)your job and lifestyle 3)Your Diet (veg/nonveg) or mixed 4)any preexisting medical conditions I would give you advice regarding the exercise regime u need to follow and also weather u would need any supplimentary intake based on the above queries i asked you. Take care Regards.