- [Narrator] Exercising is supposed to be good for you.
It can help you stay at a healthy weight,
improve your cardiovascular health,
and even ward off depression.
But, like most things, it's possible to over-do it.
And getting too much exercise can have serious consequences
on your body and brain.
So what exactly is too much exercising?
Well, it depends on factors
like your age, health, and choice of workouts.
But in general, adults should get about
five hours a week of moderate exercise,
or two and half hours or more of intense activity.
Or some combination of the two.
That's according the CDC.
But research shows that going way above and beyond
doesn't necessarily increase your health benefits.
One unsurprising study found
that light to moderate runners
had a lower risk of death than people who didn't exercise.
But in a surprising turn,
some people who ran at a faster pace
for more than three times a week
had a similar risk of dying as non-runners.
So running too much and too intensely
seems to undo some of the health benefits
gained from regular running.
Extreme endurance exercises, like ultra-marathons,
may also lead to heart damage, heart rhythms disorders,
and enlarged arteries in some people.
Experts believe that extreme endurance
puts extreme demands on the cardiovascular system.
One study found that repeated extreme exercises
can remodel the heart, thickening the muscles' walls
and scarring tissue.
Another study showed that women were less likely
to have a heart attack or stroke
if they were physically active at least once a week.
But that risk of heart attacks and strokes
shot up for women who exercise strenuously every day.
So excessive exercise doesn't provide more benefits
than moderate exercise, and it could be more risky.
Women are at a particular risk for what's known as
Female Athlete Triad.
That includes loss of menstruation, osteoporosis,
or bone mineral loss, and eating disorders.
These symptoms usually arrive from a combination
of over-exercise and calorie restriction.
For men, intense exercise has been shown to decrease libido,
possible due to physical fatigue,
and lower testosterone levels.
For both men and women, over-exercise raises the risk
of over-use injuries, like tendonitis and stress fractures.
These injuries result from repetitive trauma.
Your immune system can likewise suffer.
While moderate exercise can improve your immune system,
excessive exercise can actually suppress it.
There's up to a 72-hour open window of impaired immunity
after intense exercise.
This basically means that viruses and bacteria
have an easier time invading and infecting the body.
And athletes who over-exercised also experienced
more upper-respiratory tract infections.
So we know excessive exercise can wreak havoc on your body,
particularly your heart, tendons,
ligaments and immune system.
And for around one million people in the US,
exercise addiction is wreaking havoc on their brains.
Symptoms of exercise addiction include withdrawal.
That's when you feel anxious or exhausted
when you miss a workout.
Or feeling a lack of control
and unable to cut down on exercise,
even when you know it's hurting you.
Now, it's important to understand
that you shouldn't just give up on exercising.
The key is to get the right amount.
So feel free, go forth and run!
Just not all the time.