Do you work out moderately or excessively? Studies have shown that working out moderately or excessively can effect your immune system and white blood cell count. During a workout, the amount of white blood cells increase while the amount of white blood cells drop rapidly after you're done working out. In the past, scientists thought that having strenuous workouts resulted in fewer white blood cells in-comparison to before you worked out. But new studies suggests that it depends on the type of workout. Moderate workouts, such as a jog, will protect one from upper respiratory illnesses. Harder workouts tend to increase the risk for upper respiratory illnesses. If you prefer harder workouts, scientists suggest eating carbohydrates. "Ingesting carbohydrates during vagarious exercise may help because carbohydrates maintain blood sugar levels. Having stable blood sugar levels reduces the body's stress response, which in turn, moderates any undesirable mobilization of immune cells." Washing your hands after working out will also help you stay healthy.