Springtime signals warmer weather and, for many people, more time outside. A garden can be a great place to get sunlight (to support vitamin D production), physical activity and delicious fresh fruits and veggies. When you go out to plant, water and weed your garden this year, keep an eye on how well-watered you are to prevent yourself from getting dehydrated.
Gardening is a hidden form of exercise because you squat, bend and stand without even thinking about it. But the constant changing of positions requires your body to perform a complex balancing act. Every time you stand up, your blood vessels coordinate a rapid sequence of expansion (dilation) and narrowing (constriction) to keep the blood pumping around your body and to your head. The body uses a feedback system called the baroreflex to prevent your blood pressure from getting too high or too low. However, dehydration makes it more difficult for our baroreflex to regulate blood pressure.
Gravity pulls blood from your head toward your feet to regulate blood pressure, making standing up a challenge to the cardiovascular system even in moderate temperatures. It becomes more difficult— particularly for older adults—to be out in the hot sun without drinking enough fluids. When you do not drink enough water, there is less fluid moving through your bloodstream. This can cause blood pressure to dip too low. Blood pressure needs to be high enough to keep your blood flowing to the head to prevent dizziness and fainting.
To avoid passing out when you are picking flowers or tomatoes, keep water nearby to drink. Don’t wait until you feel thirsty to drink—you can lose up to 10 percent of your blood volume before you feel thirsty. Drink water before going outside, sip a cold beverage frequently while you’re out in the heat and continue “watering” yourself after you come inside.
Enjoy the outdoors and the (literal) fruits of your labor this spring, but do so with a water bottle in hand.
Special thanks to the APS Communications and Editorial Staff, Austin Robinson, PhD, and Jennifer Whitacre for their assistance.