Working out is healthy, with the U.S. Department of Health and Human Services recommending 75 to150 minutes of cardiovascular exercise each week and twice-weekly strength-training sessions. You might feel like throwing up after a workout, depending on what you do and how hard you exert yourself. Post-workout nausea has some common, preventable causes.
You might feel like throwing up after a workout 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 will rise in response to the sugar, causing a blood sugar drop.
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.
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.
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 in motion. If your post-workout nausea persists or worsens, consult your doctor to rule out other, more serious causes.