Question

why we get muscle cramp after the day exercise

Answer 1

because when we exercise the oxygen is deficient to break glucose which cause formation of lactic acid and due to this lactic acid we suffer from cramps.

Answer 2

It happens because of lack of Ions like sodium , potassium .There are others causes like narrowed blood vessels , compression of a nerve , spinal stenosis, in some cases hypothyroidism etc . The imbalanced diet also causes the cramps , and the main factor is loss of water or dehydration