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In Brief: Thrill rides may be heartfelt

In Brief

Thrill rides may be heartfelt

Now that it's summertime, millions of us will set out for an amusement park or a state or county fair. No one needs to be told that the some of the rides you'll find there — particularly the roller coasters — are not for the faint of heart. It turns out that they may not be good for the infirm of heart, either.

Researchers at the University Hospital in Mannheim, Germany, monitored the heart rates of 55 young people (average age, 28) before, during, and after they rode Expedition GeForce, a roller coaster in Hassloch, Germany.

Before they got on, the average heart rate of the study's participants was 91 beats per minute, a bit above the healthy resting rate of 60–80 beats per minute, and perhaps an indication that they were nervous, but nothing exceptional.

This was a relatively tame roller coaster ride with a maximum speed of about 75 miles an hour; some rides these days go over 120 miles per hour. Still, halfway through the two-minute ride, the study participants' hearts were pounding at a rate of 153 beats per minute on average. To the researchers' surprise, the biggest increase came during the early, ascending part of the ride, not the steep descents that pack the G-forces and create the frightening sensation of falling.

The ride also had a lingering effect: About half of the riders had irregular heartbeats for several minutes after they got off, even after their heart rates returned to normal.

Mind you, getting your heart going isn't bad. While the health benefits of moderate physical activity like walking are legion, aerobic exercise — the type that speeds up your heart and makes you breathe harder than normal — does have additional cardiovascular benefits. The American Heart Association (AHA) recommends a gradual start to an aerobic exercise program but sets 50%–75% of your maximum heart rate as the "target zone" for a good workout (see chart).

*50%–75% of average maximum heart rate †Average maximum heart rate can be calculated by subtracting your age from 220, e.g., 220 – 60 = 160. Source: American Heart Association Web site, accessed April 2006.

After about six months of regular workouts, the AHA says you may be able to exercise comfortably when your heart is beating at 85% of its safe maximum rate.

For many people, the faster heart rate during a roller coaster ride is well within that limit. As the researchers pointed out when they reported their results at an AHA meeting in late 2005, younger people without heart disease needn't worry about a heart-pounding ride turning into heart-stopping one.

The same cannot be said, though, if you have a heart condition or high blood pressure. The sudden increase in heart rate might be dangerous. In April 2006, a 49-year-old woman died after riding Mission: Space, a ride at Disney's Epcot Center that spins people with twice the force of Earth's gravity. News reports said early autopsy results showed she died from a stroke that may have been linked to high blood pressure. The previous year, a 4-year-old boy with an undiagnosed heart condition died after riding the same ride.

Last updated:	September 05, 2008