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Young, old or in-between: No one is immune to the occasional bout of low energy and weariness. In fact, fatigue is the top complaint at about 5 million doctor appointments per year, according to Kurt Kroenke, a professor of medicine at the Indiana University School of Medicine and core investigator at the Veterans Affairs Center for Health Information and Communication.

For many people, though, there’s no medical problem draining their batteries. “Stress, poor diet, poor quality sleep, lack of exercise and limited bright-light exposure during the day can all contribute to fatigue,” says Shelby F. Harris, director of the Behavioral Sleep Medicine Program at Montefiore Medical Center in New York.

Timed right, small changes in your routine can give you a lift during the day and improve sleep. See your doctor if you have other symptoms — such as unexplained weight gain or loss, fever, shortness of breath, morning headaches or difficulty concentrating — or you recently started a new medication. Otherwise, give these strategies a try for a month to see whether your energy levels reboot.

Morning

Let the sunshine in. The brain makes melatonin, the hormone that causes sleepiness, when it’s dark. Morning light helps stop the production of melatonin, Harris says. Upon awakening, open the curtains or shades, sit by a window (even if it’s cloudy outdoors) while you eat breakfast, or take a morning walk. And continue to expose yourself to light during the day to keep your body’s sleep-wake cycle synchronized; this helps combat daytime sleepiness and promotes better nighttime shut-eye.

Take a drink break. Even mild dehydration can zap energy, memory and attention, according to a 2016 study published in the American Journal of Clinical Nutrition. Older adults can have a tougher time staying hydrated, in part because the mechanism that triggers thirst may become less efficient with age. To compensate, make it a point to drink at regular intervals throughout the day, beginning in the morning. Coffee and tea count (they have only a mild diuretic effect, if any), as do foods with a high water content, such as soup and most fruits and vegetables.

Afternoon

Get moving. It seems counterintuitive, but physical activity is a powerful antidote for fatigue. And it doesn’t have to be strenuous: In a small University of Georgia study, couch potatoes who engaged in a 20-minute, ­low-intensity aerobic exercise routine three times per week for six weeks reduced their fatigue by 65 percent; those who engaged in moderate-intensity exercise lowered it by 49 percent.

Stop sipping coffee and tea. Thanks to their caffeine, both are great pick-me-ups, but it’s a good idea to limit the stimulant to 400 milligrams per day (roughly two to four eight-ounce cups of coffee) and to taper off by late afternoon. Caffeine can disrupt sleep when it’s consumed even six hours before bedtime.

Evening

Power down. Dim the lights, switch off the TV and put away smartphones, tablets and computers at least an hour before bedtime. This will trigger your brain to start producing melatonin.

Make over your bedtime habits. In a 2015 Consumer Reports survey of 4,023 adults, 68 percent said they had trouble sleeping at least once a week. Too little or poor-quality sleep can cause daytime droopiness. To get the seven to nine hours of slumber you need to restore body and mind, improve your sleep hygiene. Keep your bedroom dark, use your bed only for sex and sleep (no pets allowed), and stick with a regular sleep schedule.

Address your stress. Sometimes it’s difficult to separate physical fatigue from the mental drain caused by life’s demands and worries. Harris recommends listening to a meditation or relaxation app before bed. “Mindful meditation quiets your mind, so your brain isn’t hijacked by anxious or racing thoughts of the day or by what has to be done in the future,” she says. “It centers you and helps set the stage for sleep.”

Copyright 2017. Consumers Union of United States Inc.

For further guidance, go to ConsumerReports.org/Health, where more detailed information, including CR’s ratings of prescription drugs, treatments, hospitals and healthy-living products, is available to subscribers.