Working out is healthy, with the U.S. Department of Health and Human Services recommending 150 to 300 minutes of cardiovascular exercise each week and twice-weekly strength-training sessions for adults. Still you might feel like throwing up after a workout, depending on what you do and how hard you exert yourself. Feeling sick after a workout has some common, preventable causes.
Nausea after a workout is commonly caused by low blood sugar, dehydration or motion sickness. If your nausea continues or gets worse, contact your doctor to rule out more serious medical conditions.
Low Blood Sugar
You might feel like throwing up after exercise because your blood sugar is low, particularly if you exercise immediately after you wake up in the morning without eating breakfast first or have not eaten for several hours prior to a workout.
Many exercises, like sprinting, weightlifting and calisthenics, are anaerobic and make you feel dizzy and nauseated afterward if you have fasted for 10 to 12 hours, cautions fitness specialist Stew Smith. Eating or drinking sugary foods and beverages before a workout may cause nausea for the same reason — because your insulin rises in response to the sugar, causing a blood sugar drop.
Nausea From Dehydration
A vigorous workout makes you sweat, and your body gets dehydrated if you do not replenish the lost fluid during and after your exercise session. People performing lengthy workouts and endurance athletes are at particularly high risk because dehydration chances increase with lengthy workouts.
Nausea is one of the signs of dehydration, so you may feel like throwing up if you lost too much water and did not drink enough to replace it while working out.
Motion Sickness From Exercise
Certain types of exercise cause motion sickness in some people, making them feel like throwing up. This effect happens if you do abdominal exercises like crunches, particularly if you close your eyes or look at different spots on the ceiling while you are in motion.
You get a similar effect to motion in a car, on board a ship or in another circumstance that causes movement-related nausea.
Medical Causes of Exercise-Induced Nausea
If your nausea after exercise worsens or continues despite taking preventive measures, consult your doctor as there may be a more serious underlying condition. Other possible causes include heat stroke, acute renal failure, gallbladder adhesion and pancreatitis.
Preventing Nausea After Exercise
Prevent nausea after workouts by drinking water before you exercise and throughout your exercise session to ensure you stay hydrated, particularly if you are doing intense activity.
Eat protein before working out, but avoid anything containing sugar for at least an hour beforehand. This ensures that your blood sugar level is high enough at the beginning of your workout routine and does not take a sudden drop.
Pick a certain point on the ceiling on which to visually focus while doing abdominal exercises and keep your eyes open while you're in motion. If your post-workout nausea persists or worsens, consult your doctor to rule out other more serious causes.