After a night of sleep, you may wake up slightly dehydrated. Even mild dehydration can contribute to low energy, fatigue, and digestive issues. Drinking a glass of water in the morning can restore hydration, support digestion, and help you feel more alert as you start your day.
Hydration plays a key role in how alert and focused you feel. When you’re not drinking enough fluids, it can affect blood flow to the brain. You may notice fatigue, brain fog, or difficulty concentrating.
In one study, young adults who went 12 hours without fluids had slower reaction times, greater fatigue, and poorer memory and attention than those who were well hydrated.
Another study found that drinking about two cups of water (500 milliliters) before bed and again in the morning may improve alertness and reaction speed.
If tiredness is caused by poor sleep, stress, or an existing health condition, drinking water may not make a noticeable difference. However, staying hydrated may help you feel more alert and less tired if dehydration is the cause.
Drinking water in the morning can prepare your digestive system for the day ahead. Fluids help food and waste move through the digestive tract. When you do not drink enough, stool may move more slowly, which can lead to constipation.
Water also keeps stool soft and easier to pass. Research shows that people who consume adequate fluids and water-rich foods have a lower risk of constipation, and the risk continues to decline as intake increases.
During digestion, your small intestine pulls water from your bloodstream into your gut to break down food.
Some people report that drinking water in the morning helps trigger a bowel movement, especially when paired with physical activity or coffee. If you’re already drinking enough fluids, you may not notice a significant difference.
Drinking water in the morning can be helpful, but timing matters less than total fluid intake.
Most women need about 11.5 cups of water daily, and men about 15.5 cups, including fluids from both drinks and foods. Because foods like fruits, vegetables, and soups contain water, experts suggest aiming for about nine cups of water per day for women and 13 cups for men.
Starting the day with water can give you a head start, especially if you tend to forget to drink later.
For most people, starting with one glass of water (about 8–16 ounces) is a good place to begin. Drinking a lot at once isn’t needed and may feel uncomfortable.
Despite common claims, a few beliefs about morning water are not supported by research:
- Warm water boosts metabolism: Water temperature does not significantly affect metabolism.
- Cold water is bad for digestion: There is no strong evidence that cold water affects digestion. A small study suggests very cold water may slow stomach movement and reduce appetite, but research is limited. Cold and room-temperature water hydrate the body equally.
- Drinking more than you need adds benefits: Once your hydration needs are met, extra water does not provide added health benefits. In rare cases, excessive water intake can dilute sodium levels and disrupt the body’s normal fluid balance.
Also, some people need to limit fluids. If you have heart failure, kidney disease, or have been told to limit fluids, talk with a healthcare provider about how much you should drink.
For most healthy adults, drinking to satisfy thirst is a good rule of thumb. Pale yellow urine usually means you’re well hydrated. Dark urine may indicate the need for more fluids.
Some people are more likely to notice benefits from morning hydration.
May benefit most:
- People who don’t drink enough fluids
- Those prone to constipation
- Individuals who wake feeling sluggish
- Older adults who may not feel thirst as strongly
May notice little difference:
- People who already meet their daily hydration needs
- Those who drink most of their fluids late in the evening
- Individuals whose fatigue is related to sleep or health issues
Small habits, like starting your day with water, can make staying hydrated easier. If plain water feels boring, try adding lemon, sipping herbal tea, or eating water-rich foods like fruit to help you stay hydrated.
