Severe reactions can then result. Reduction of insulin dosage is the only way to prevent reactions in such cases. Often a combination of some reduction in insulin dosage and eating extra snacks turns out to be the best solution. It is currently believed that exercise increases the number of insulin receptors on a cell. It is thus easier for the insulin to attach to the surface of the cell, allowing sugar to move across the cell membrane into the cell.
Exercise is the only way known to increase the number of insulin receptors on a human cell.