I did some stand up exercises yesterday morning which consisted of standing touching my toes. I didn't do it for long. However,after a few seconds, I became dizzy ( resulting from the repeated bending down to touch toes) and this then developed in to sinus pain which I still have. I'm thinking this may be due to some kind of vertigo with the type of exercise I carried out? I'm not sure. I do suffer with sinusitis but I haven't developed it this way before.