It’s not unusual to feel nauseous or sick after a workout sometimes. You can often get relief by prepping before, during, and after your workout.

Let’s look at the common reasons why you may feel sick after a workout and tips to prevent it from happening again.

When we work out, we lose fluid as we sweat and breathe hard. It’s easy to become dehydrated during strenuous exercise. Symptoms of dehydration include:

But be careful, because you can also drink too much water and dilute your electrolyte levels. If the sodium concentration is too low in your blood (hyponatremia), you may feel nauseous.

During and after intense exercise, it’s a good idea to incorporate electrolyte drinks to replenish lost sodium and other electrolytes.

How much water should I drink when working out?

The American Heart Association recommends drinking water before you exercise as well as while you’re working out, offering two rules to follow:

  1. If you’re thirsty, you’re already dehydrated.
  2. If your urine color is pale to clear, you’re properly hydrated; if it’s darker, you need more fluids.

The American College of Sports Medicine recommends the following:

  • Prehydrate several hours before your workout or event, like a race. Slowly drink 5 to 7 milliliters of fluid per kilogram of body weight.
  • Hydrate during the workout or event to prevent excessive water loss. This is defined as greater than 2 percent of body weight.
  • After the workout or event, drink around 1.5 liters of fluid for every kilogram of weight lost during the exercise.

You must properly fuel your organs and muscles. If you haven’t eaten enough of the right kinds of food between workouts, your body may not be properly fueled for exercising. This can make you feel sick.

Symptoms of inadequate nutrition include:

Avoid eating too close to your workout, though, especially foods like protein and fat. They can take longer to digest.

What and when should I eat for optimal workouts?

Don’t eat too much before exercising. According to the Mayo Clinic, you can eat large meals three to four hours before working out and small meals or snacks one to three hours before.

If you want to eat just before or during your workout, try carbohydrate-rich foods, such as:

Within two hours after exercising, eat a meal focused on carbohydrates and proteins, such as:

  • peanut butter sandwich
  • low-fat chocolate milk
  • smoothie
  • vegetables

Along with nutrition and hydration, other factors can influence how you feel during and after a workout, such as:

  • Type of workout. “Bouncy” workouts, such as aerobics or running, can make some people feel more nauseous than “smoother” workouts, like the stationary bike or elliptical.
  • Intensity. Pushing yourself harder than you’re ready for can result in a number of problems, including strains, sprains, and generally not feeling well.
  • Skipping warmup and cooldown. Not properly beginning and ending your workouts may result in a sick or nauseous feeling.
  • Temperature. Working out in heat, whether it’s hot yoga or running outside on a sunny day, can dehydrate you faster and lower your blood pressure. This can result in muscle cramping, heatstroke, and heat exhaustion.

Consider the following tips to prevent feeling sick:

  • Alter the type and intensity of your workout. Speak with a personal trainer at your gym for advice.
  • Adjust the temperature if you’re working out inside.
  • Use warmup and cooldown sessions to bracket your workout.

By paying attention to hydration and nutrition, you may be able to lessen a sick or nauseous feeling after your workout.

If you don’t see any improvement after making these tweaks, speak to a healthcare provider for guidance.