A:It’s important to drink enough ;uids before, during, and a;er
your workout, particularly in the
summer, when temperatures climb.
How much should I drink to stay hydrated
whi;e I exercise? Are electrolytes necessar;?
CARLA COX, PHD, RD,
CDE, CSSD, FAADE
WHAT TO KNOW
People with diabetes have the same
risk for dehydration during exercise as
everyone else—except when blood
glucose levels are elevated. As
glucose in the blood rises, more ;uid
is sent into the bloodstream to dilute
the glucose. This leads to frequent
urination in larger amounts, which
lowers the body’s total ;uid.
How much you need to drink to
stay hydrated depends on a number of
factors, including your weight, ;tness
level, the air temperature, time spent
exercising, and whether you’re
exercising indoors or outside.
FIND OUT MORE
It’s important to be well hydrated
before you begin any physical activity.
That means drinking ;uids one to two
hours before you start. For workouts
that will last an hour or less, aim for 3
to 8 ;uid ounces of water every 15 to
If you’re engaging in intense
activity for more than an hour or in
very hot weather, you’ll need to
hydrate and keep your blood glucose
from going too low. Sports drinks with
glucose and electrolytes (minerals
that help the body maintain normal
;uid levels) are a good choice. They
can also help you replenish sodium, an
electrolyte that helps hold ;uid in the
bloodstream, which you lose while
sweating. Stay hydrated by drinking
4 to 8 ounces of sports drink every 15
to 20 minutes. (Each 8-ounce cup
should have an average of 15;grams of
carbohydrate. The general
recommendation for blood glucose
management during intense exercise
is to eat or drink up to 60 grams of
carbohydrate per hour. Adjust this
amount depending on your personal
needs.) If you prefer water, get
glucose and electrolytes through
Not sure whether you’re drinking
enough? Check the color of your
urine: If it’s pale yellow, you’re well
hydrated. Dark urine indicates your
body needs ;uid.
Be alert for signs of dehydration.
They include dry mouth, excessive
thirst, light-headedness, and
headache. Symptoms of dehydration
may be mistaken for low or high blood
glucose—and vice versa. While working
out, check your blood glucose as
directed for the type of medication you
take. Your doctor may ask you to check
before, during, and a;er exercise.
Before you begin your exercise
routine, weigh yourself. When you’re
;nished, drink three cups of ;uid for
every pound of weight lost due to
sweating in order to replenish what you
lost during your activity. Alternatively,
drink enough until your thirst is satis;ed.
Maintain your blood glucose targets
in the hours leading up to exercise,
consume ;uids about one to two
hours prior to exercise, and be sure to
drink while you’re working out. Learn
the symptoms of dehydration and
treat immediately to avoid further
dehydration. Don’t forget to rehydrate
a;er your workout.
Carla Cox, PhD, RD, CDE, CSSD,
FAADE, is a diabetes educator and
has worked with people with diabetes
for over 30 years.