Feeling cranky, fatigued and unable to focus? You might just need a drink of water, according to new research.

The small study, published in the Journal of Nutrition, tested mood, concentration and mental skills in 25 women who either were given enough fluids to remain optimally hydrated or were induced into a mildly dehydrated state. Dehydration was achieved through either exercise alone or by using both exercise and a diuretic drug that increased urination.

The women’s mood and cognitive abilities were tested during exercise and at rest under the different hydration conditions. On most mental tests, the women’s state of hydration didn’t affect performance, but being dehydrated did cause headache symptoms, loss of focus, a sense of fatigue and low mood both at rest and during exercise. The dehydration induced in the study was not severe: it was around 1% lower than optimal.

Although men weren’t included in the research, the results likely apply to them as well. So if you’re feeling a bit snarky or blah, it might make sense to hit the watercooler or have another type of refreshing drink — especially after a workout. Keep in mind that plain water or other nonalcoholic and caffeine-free drinks are best for fighting dehydration.

To check your own hydration state, peek at the color of your urine: if it’s darker rather than nearly clear, you need more water.

While the old maxim about drinking eight glasses of water a day has been widely debunked as myth, this and other research suggests that maintaining good hydration (if not quite that much!) is healthy.

Article taken from Time.