Have you ever felt heavier or looked more bloated after a workout than you did before? As frustrating as that may be, you're not alone. While the reasons can vary, you didn't somehow undo all your hard work, if that's what you're thinking. This is most common after an intense workout and can be a result of factors like water retention or inflammation. See if any of the five possibilities below can be the cause of your post-workout bloat.Dehydration: Bloating is often your body's response to lack of fluids; when there's not enough, your stomach retains water to compensate and visibly swells. Be sure to hydrate before and throughout your workout to prevent this from happening. Dehydration can also cause constipation, which could be the reason for your bloat. Overhydration: Yes, there is such thing as drinking too much water, too fast. Taking big gulps of water during high-intensity workouts can lead to a condition called hyponatremia, which dilutes the sodium in your body. A combination of sweating and replenishing your body too quickly with excessive amounts of water can make your cells retain water. Inflammation: As your body repairs itself after intense exercise, it sends extra fluid to your tissues to help patch up micro muscle tears. This is a normal process, and actually important for recovery, but that excess fluid may make you feel heavier than you did before your workout. Heat: If you typically notice bloating after working out in hot weather or inside a stuffy gym, heat could be adding to the problem. Your body releases sodium and water as you sweat, but this can also cause it to retain water as a response to lost fluids. Try to work out in well-air-conditioned gyms and avoid wearing gear that's too tight or that isn't breathable. Your body isn't used to intense activity: Whether you've just begun your fitness journey or you're getting back into the swing of things, bloating may be a natural response to stress. Your body releases cortisol (the stress hormone) during exercise, which can impact your fluids and cause your body to retain water. But don't worry — allow your body to adjust to your new workout regimen and the bloating should disappear after a couple weeks.