Do you drink enough water? How do you know? Guidelines for fluid intake are not especially well researched and therefore less well known, so it’s understandable that this is a bit of guess work. Fortunately, our culture obviously embraces hydration with water bottles sold in a rainbow of colors and various sizes everywhere from supermarkets to gift shops. Forty years ago, hydration was far less understood. I recall taking a tennis lesson as a kid one summer afternoon and being very hot and thirsty. After some pleading on my end, the instructor finally let me have some water when I drooped to near dysfunction. I was allowed a mouthful of water and told to spit it out for fear of… cramps? I don’t clearly remember the rationale for restricting fluids, but I now recognize a reason why I avoided exercise as a kid. I would get hot and thirsty to the point of illness. I’m happy to report, fear of drinking water is no longer a barrier to activity.
Hydrating in winter is not as intuitive as hydrating in summer. That’s why I’ve chosen this topic for a winter conversation. People don’t feel as thirsty in winter, and this can cause dehydration. Cold dampens thirst. Cold temperatures shunt blood away from extremities towards internal organs to decrease heat loss. As a result, the brain is not triggered that blood volume is reduced, even though it is. Core temperature protection trumps hydration in this biological trade-off. Cold weather thirst is reduced up to 40 percent according to Robert Kenefick, University of New Hampshire associate professor of kinesiology. But our hydration needs are not reduced and thus dehydration is a significant risk, especially for those who rely on thirst to motivate drinking.
Dry winter air causes sweat to evaporate quickly, so we don’t notice water loss when our bodies are working hard to stay warm. Lower blood volume caused by mild dehydration means the heart works harder for circulation, and older adults have decreased thirst. So, older adults with any cardiac health concerns might pay particular attention to winter hydration.
Complicating matters, thirst generally under-functions in telling us to drink. By the time we feel thirst, we’ve already experienced a downturn in energy due to mild dehydration. Whether you’re an athlete or just getting through the day at the office, when you feel thirsty, you’re already performing at diminished capacity.
Some signs of mild dehydration include fatigue, reduced endurance, poor temperature regulation, reduced motivation, irritability, and increased perception of the difficulty of things. For some, this sounds like every afternoon around 3 p.m.! Back in the era of no water for kids playing tennis, there was an advertisement campaign for Snickers that said, “Low energy mid-afternoon? Reach for a Snickers!” It showed a bedraggled office-worker opening a desk drawer, taking a large bite of a candy bar, blissfully chewing, then transforming into an energized, neatly coiffed, professional powerhouse. Snickers was the answer to low energy and bad hair. Feel sluggish? Maybe you need a break from work, maybe you need a nap, maybe you need a turkey sandwich, or maybe you need 16 ounces of water. We know for certain you don’t need a Snickers. Reaching for a large glass of water is the easiest thing possible and quite possibly the perfect response. There’s virtually no downside.
So how do you know if you’re drinking enough? Urine should be very pale or nearly clear. A good rule of thumb is to drink half your body weight (in pounds) in ounces. For example, a 160-pound person should aim for 80 ounces of water. Although water is the best beverage, almost all beverages count. If you’re chilly in winter, drink warm beverages such as herbal tea, or just water and lemon. And remember, fruits and vegetables also carry lots of nourishing hydration.
Drink in advance of thirst. One of my favorite strategies for good hydration is to keep a glass in the bathroom. The “rule” is that every time you pee, you can’t leave the bathroom until you’ve had another glass of water. Another idea is to fill a clean milk jug with all the water you need in a day and fill a glass from it incrementally throughout the day.
Hydration is one of the most readily accessible things we can do for our wellbeing and energy, so drink up! See you out there.