Squash player, 43 max hr is 177. i hit 177 in a rally. now when i do cardio i get a tingly left face. had that before when dehydrated. is it a clot?

See a doctor: Tingling on the left side of the face during exercise is not normal and could be a sign of significant disease. Not everyone with heart disease experiences classic chest pain. Please see a doctor for examination and appropriate tests.

It could: be decreased blood flow as your heart is pumping very rapidly and does not have a chance to distribute enough blood to other areas, could also be a nerve problem. Do be sure, visit your doctor for imaging as well as neuro studies.