The crowds running in marathons are getting bigger—more people are
relishing the challenge and the dedication it takes to cross the finish
line. And it’s not just the marathon—supercharged exercises
that push people to the limits of their endurance, like triathlons, cross-training,
and high-intensity home video workouts, are experiencing record participation
levels throughout the United States.
Any form of exercise that goes for more than four hours at a stretch, or
for consecutive days in the case of endurance exercise, is generally considered
extreme. This kind of commitment doesn’t come without risks. On
occasion, elite long-distance runners, triathletes, or endurance sport
enthusiasts have suffered heart attacks, raising questions over whether
years of boundary-pushing exercise are too hard on the heart.
“For most people, strenuous exercise is a good thing,” says
Aidan Raney, MD, an interventional cardiologist at
St. Joseph Heritage Medical Group in Orange. “Grueling physical activity that pushes the muscles and
lungs to their limit also makes intense demands on the heart, and making
the heart work hard is the key to a whole range of associated health benefits.
This includes everything from decreased depression to living a longer
For a minority of people, including those who have pre-existing cardiac
conditions, extreme endurance exercise has been linked to the onset of
irregular heartbeats. After finishing extreme running events, some runners
have been found to exhibit biomarkers in their blood that are associated
with heart damage.
And heart muscle scarring has been found with greater frequency in lifelong
marathoners and ultramarathoners than in runners who train and compete
more moderately. However, no cause-and-effect relationship has been established
between high-intensity exercise and damage to the heart.
“The long-term risk of heart damage from extreme exercise is, for
the vast majority, much smaller than the risk of cardiovascular disease
resulting from being inactive,” Dr. Raney says. “Except for
those with symptoms or pre-existing conditions, a potential heart problem
in the future is not a reason to avoid exercise today.”
Dr. Raney advises aspiring extreme athletes to be aware of the increased
likelihood of injury. As you become tired, your technique starts to suffer;
the more you push past the point of exhaustion, the greater the chance
you will get hurt. People who run may trip and fall and athletes who do
CrossFit may sprain or tear a muscle lifting weights. Maintaining good
form takes practice, and the more experience you get, the longer you’ll
be able to exercise in a safe and effective way.
What should you do first if you want to run a marathon or get into a hard-core
“The key is steady training and building from a baseline, which includes
checking in with your doctor before starting to train,” says Dr.
Raney. “You want to be aware of any issues with your joints, muscles,
and cardiovascular system that could be exacerbated by plunging into the
activity. Serious athletes train in cycles that include built-in rest
Dr. Raney encourages people not to shy away from taking on a properly supervised
regimen that is as intense as they can handle.
“There are so many ways that exercise is good for you and so many
ways that not exercising is bad for you. From preventing obesity, to maintaining
the vitality of your heart and lungs, to stimulating the production of
the mood-improving hormone serotonin, exercise of any sort is essential
to good health. And intensive exercise is an efficient and highly effective
way to strengthen your muscles and build your stamina,” Dr. Raney says.
So pin that number to your tank top, post that finish-line photo to Facebook,
and put yourself to an ultimate exercise challenge.
What is your proudest exercise accomplishment? Share your comment below.
Learn more about
Dr. Raney. Learn more about
St. Joseph Heritage Medical Group.