There’s no doubt that water is essential to your health. Accounting for up to 60 – 70 % of your body weight, water plays a key role in regulating everything from brain function to physical performance to digestion — and much more.

Still, while it’s clear that drinking enough water is important to health, you may wonder whether timing matters.

This article takes a look at the evidence to evaluate the best time to drink water.

In the morning
Enjoying a glass of water first thing in the morning is a simple way to start your day off on the right foot. Some may also find that drinking water right when they wake up makes it easier to maintain healthy hydration habits and increase fluid intake throughout the day.

If you’re dehydrated, increasing your daily water intake can help boost your hydration levels, which may be especially beneficial for improving mood, brain function, and energy levels.

In fact, studies show that even mild dehydration can negatively affect memory, concentration, anxiety levels, and fatigue (Ganio et al.2011; Benefer et al.2013). However, while some may find that drinking water in the morning works for them, there’s no evidence to suggest that it’s any more beneficial to drink water in the morning than at other times during the day.

SUMMARY
Drinking water first thing in the morning can help start your day on the right foot. However, while it may help some people increase their daily water intake, there’s no evidence to suggest that drinking water in the morning is particularly beneficial.

Before meals
Drinking a glass of water just before eating a meal is a great strategy if you’re trying to lose weight.

Doing so can not only help enhance feelings of fullness but also decrease your intake during that meal.

For instance, one study in 24 older adults found that drinking 16.9 ounces (500 mL) of water 30 minutes before breakfast reduced the number of calories consumed by 13%, compared with a control group (Davy et al.2008) Another study in 50 people showed that drinking 12.5–16.9 ounces (300–500 mL) of water before lunch decreased hunger and calorie intake in older adults (Van et al.2007) However, while all participants reported increased feelings of fullness, no significant differences in calorie intake or hunger levels were observed in young adults (Van et al.2007)

Therefore, although drinking water before meals can be an effective method to support hydration, more research is needed to determine whether it can also promote weight loss in younger individuals.

SUMMARY
Drinking water before a meal may help decrease the number of calories consumed at that meal, especially in older adults.

Before and after exercise
When you work out, you lose water and electrolytes through sweat.

Drinking plenty of water before and after exercising is important to keep your body hydrated and help replenish any lost fluids. Excessive fluid losses during your workout can also harm physical performance and cause electrolyte imbalances. It’s recommended to drink water or an electrolyte drink after exercising to help replace any lost fluids and optimize performance and recovery (Sawka et al.2007)

SUMMARY
Drinking plenty of water before and after exercising can help replenish fluids and maximize performance and recovery.

Consistency is key
Your body tightly regulates water balance during the day, and excess water is excreted out of your body via your skin, lungs, kidneys, and digestive system. However, your body is only able to eliminate a certain amount of water at a time.

Although uncommon, drinking too much water can disrupt your body’s sodium levels and fluid balance, causing serious side effects like headache, confusion, fatigue, seizures, and coma. Therefore, instead of drinking large amounts of water at once, it’s important to space out your intake during the day to stay hydrated.

Try setting a timer to remind yourself to drink at regular intervals, and keep a glass of water on hand throughout the day to help you reach your goals.

SUMMARY
Your body tightly regulates its water balance, and drinking too much at one time can lead to serious side effects. Therefore, it’s best to space out your water intake and drink water consistently throughout the day.

The bottom line
Enjoying a glass of water first thing in the morning may make it easier to maintain healthy habits and increase your daily water intake. Drinking water before meals can help increase feelings of fullness and may promote weight loss in older adults. Finally, drinking water before and after exercise can replenish any lost fluids to optimize performance and recovery. However, the most important thing is to drink water consistently throughout the day to stay hydrated.

References:

1. Ganio, M. S., Armstrong, L. E., Casa, D. J., McDermott, B. P., Lee, E. C., Yamamoto, L. M., Marzano, S., Lopez, R. M., Jimenez, L., Le Bellego, L., Chevillotte, E., & Lieberman, H. R. (2011). Mild dehydration impairs cognitive performance and mood of men. The British journal of nutrition, 106(10), 1535–1543. https://doi.org/10.1017/S0007114511002005
2. Benefer, M. D., Corfe, B. M., Russell, J. M., Short, R., & Barker, M. E. (2013). Water intake and post-exercise cognitive performance: an observational study of long-distance walkers and runners. European journal of nutrition, 52(2), 617–624. https://doi.org/10.1007/s00394-012-0364-y
3. Davy, B. M., Dennis, E. A., Dengo, A. L., Wilson, K. L., & Davy, K. P. (2008). Water consumption reduces energy intake at a breakfast meal in obese older adults. Journal of the American Dietetic Association, 108(7), 1236–1239. https://doi.org/10.1016/j.jada.2008.04.013
4. Van Walleghen, E. L., Orr, J. S., Gentile, C. L., & Davy, B. M. (2007). Pre-meal water consumption reduces meal energy intake in older but not younger subjects. Obesity (Silver Spring, Md.), 15(1), 93–99. https://doi.org/10.1038/oby.2007.506
5. Sawka, M. N., Burke, L. M., Eichner, E. R., Maughan, R. J., Montain, S. J., & Stachenfeld, N. S. (2007). American College of Sports Medicine position stand. Exercise and fluid replacement. Medicine and science in sports and exercise, 39(2), 377–390. https://doi.org/10.1249/mss.0b013e31802ca597