When You Think You’re Hungry
You might really be thirsty. Most people don't realize they're actually thirsty when hunger seems to strike. The brain recognizes these triggers as the same. So before you hit the pantry, drink some water first. Then give it a few minutes to see if it satisfies the urge to eat.
When You Wake Up
First thing in the morning is one of the best times to hydrate. Your body has gone through a long fast. For a simple jump start, squirt half a lemon in your first glass of a.m. water for a bright boost of antioxidant phytonutrients, vitamin C, and potassium.
Whenever You Sweat
Anything that makes you sweat -- a sauna or a hot tub, time outside on a hot, muggy day -- will cause your body to lose fluid. Ditto with exercise. As your muscles warm up, your body perspires to cast off heat. You'll need to cool down with lots of water.
Before, During, and After Exercise
You need lots of water to replace what you sweat out. How much? Before you work out or spend time outside, fill up your bottle with 16 to 20 ounces of H2O. Drink 6 to 12 ounces about every 10-15 minutes while you're active. Afterward, drink up again -- another 16 to 24 ounces.
When You're Sick
Hydration is key to healing when you're sick. Symptoms such as diarrhea, vomiting, and fever can cause extreme water loss. At the first sign of illness, drink lots of water, especially if you're not hungry. Stay away from alcohol and caffeinated drinks. They’ll dry out your system even more.
When You're on a Plane
Ever wonder why you get so parched and thirsty when you fly? It's all about altitude. The higher the plane goes, the drier the cabin air becomes -- and around half the air in your cabin flows in from outside. To combat the super-low humidity level, carry on an empty water bottle to fill up as needed during your flight.
When You Get a Massage
Your massage therapist will thank you if you drink water before you hit the table. Your muscles will be softer and more supple, which makes it easier for them to manipulate the tender tissue. This body work releases substances you should flush out afterward with plenty of water, too. This is extra important if you have a deep tissue or other heavy-duty massage.
Before Your Period
You can ease premenstrual discomfort and reduce bloating by drinking lots of water before your period, as well as during. One of the biggest causes of cramps or headaches is dehydration. A recent study of young women with dysmenorrhea -- very painful menstruation -- found that drinking more water shortened their cycles, eased pelvic pain, and lessened their need for pain relief.
When You're in a Midday Slump
It's midafternoon and your energy has left the building. Don't start a new pot of coffee, though. Instead, have a tall glass of water -- maybe sparkling to add some pizzazz -- with lemon or other flavoring to bump up your mood. Your hydration state directly affects your mood, memory, and visual perception, the British Journal of Nutrition reports.
When You Have a Headache
One of the top migraine triggers is dehydration. Some people report that even a slight dip in fluid intake can bring on an intense headache. It also can make you feel fuzzy, and in some cases even require medical treatment. Especially if you're migraine-prone, keep a water bottle handy at all times and track your intake. If you feel a twinge coming on, a glass can save your day.
Before Eating a Meal
Drinking water before a meal -- aka "preloading" -- might help you lose weight. A small study tested people who drank 500 milliliters -- that's a little over 16 ounces -- of tap or bottled water about 30 minutes before mealtimes and throughout the day as they wished. Over 12 weeks, the preloaders lost almost 3 pounds more than those who didn’t follow the protocol.
When You Want to Lose Weight
Water is more than a calorie-free way to help yourself feel full. It may also rev up your metabolism. In one study, 50 girls with extra weight drank about 2 cups of water half an hour before breakfast, lunch, and dinner with no other changes in their diet. After 8 weeks, they lost weight and lowered their body mass index and body composition scores. Water also speeds up lipolysis, your body's process of burning fat for energy.
When You Need to Be on Your Game
Did you know almost three-fourths of your brain contains fluid? If your levels dip too low, the blood vessels in this organ shrink. This can affect your coordination, short-term memory, attention span, and stamina, a Chinese study found. So if you feel tired and muddled, pass up a caffeine-charged energy drink. Simply drinking water can help you bounce back.
How Much Water Is Best?
The U.S. National Academies of Sciences, Engineering, and Medicine say more fluid is better for average, healthy adults -- 15.5 cups a day is ideal for men, while 11.5 cups a day from all food and drinks is enough for most women. But this includes hydration from food and all beverage sources. Your own needs depend on your health, how active you are, and the climate where you live. Check with your doctor on how much you need.