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Exercise in the Time of Flu

Posted by: Lourdes Lee Valeriano on October 20

This fall I am particularly keen on exercise. My 15-daughter joined the track team, and in a few short weeks I can see the transformation—in her energy, in her strength, and in her carriage. As for me, exercise has not only eased an irksome hip, but it also has helped keep me sane. Awake before dawn and can’t get back to sleep? Go to a 6:15 Bikram yoga class.

But last week a post in The New York Times’ Well blog gave me pause. It reported on two recent experiments that measured how different exercise levels affected mice’s resistance to the flu virus. The blog said “the bulk of the new research, including the mouse studies mentioned, reinforce a theory that physiologists advanced some years ago, about what they call ‘a J-shaped curve’ involving exercise and immunity.” It quoted Mary P. Miles, an associate professor of exercise sciences at Montana State University, as saying that in this model, the risk both of catching a cold or the flu and of having a particularly severe form of the infection “drop if you exercise moderately.” But the risk both of catching an illness and of becoming especially sick when you do “jumps right back up,” she says, if you exercise intensely or for a prolonged period, surpassing the risks even among the sedentary.

And what constitutes intense exercise? Inquiring moms and dads with kids in school sports want to know, especially in this season of swine flu. Most researchers “define it as a workout or race of an hour or more during which your heart rate and respiration soar and you feel as though you’re working hard,” the post said.

That seems to cover a broad range of activities and levels of exertion—from preparing for a marathon to sweating 1 ½ hours in a room heated to 105 F doing a regimen of 26 postures (in other words, a Bikram yoga class). As I forwarded the blog to a friend who plans to run the New York Marathon in two weeks, I wondered whether my daughter—who runs more than an hour after school most days—and I are also in danger of sabotaging our immune systems with too much exercise.

When I posed the question to Professor Miles, she said most studies have focused on adults. Not much research has been done on adolescent athletes—or on Bikram yoga practitioners, for that matter—and she’s not comfortable extrapolating. “The one thing that I would say is that if a person seems to be getting sick frequently, then exercise volume might be a factor to consider,” she said. That’s one way to tell whether just doing it can be doing too much.

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Reader Comments

Susanne

October 20, 2009 02:47 PM

Guess the key is to stay our of the gym when you are sick to prevent others from catching your germs.

Adrienne

October 20, 2009 04:04 PM

There's a raw food institute in Florida
where the belief is that along with healthy eating (organic and preferable raw), spirituality and moderate excersize one can actually "rebuild" their immune system. The aerobic excercisize they prefer is the rebounder, nothing wild like you might find at a local gym but a rythmic up and down.
Now, I feel good about my consistant yet fairly gentle routine. Thanks!

Diane

October 20, 2009 09:29 PM

I was curious about this and found an article that said "In fact, results from a survey conducted by the Gatorade Sports Science Institute show that nearly 90 percent of 2,700 high school and collegiate coaches and athletic trainers believe that overtraining can compromise the immune system and make athletes sick.

But can too much exercise really make you ill? A study conducted at the Los Angeles Marathon reveals that this may be the case. Results show that:

•One out of seven runners who participated in the event got sick after it was over.
•Runners training more than 60 miles a week during the two months before the race, doubled their odds for sickness compared to those training less than 20 miles a week.
But regular moderate training also appears to provide protection against colds. Eighty percent of fitness enthusiasts, for instance, reported in a recent survey that they have fewer colds than their inactive peers. "

I fall into the category of the person that engages in regular moderate training, and I rarely get the flu.

Laura

October 21, 2009 04:00 PM

My experience with both my kids is that too much exercise definitely makes them get sick more quickly. My daughter does Field Hockey at school and is on a club swim team. When she has both practices the same day, she invariably gets sick and misses the next week. She is home sick today after the first 2 hour swim practice on Sunday. Going forward, 1 hour is it!
I do think though each child is different. My son seems to be able to be more physically active before getting sick. I don't think it is male v. female, but rather other factors. He sleeps better that she does.

Lourdes

October 21, 2009 04:30 PM

Good research Diane. The Well blog also alluded to a study on marathoners. What the Gatorade survey tells me is that research on adolescent athletes on this issue is overdue.

Lourdes

October 21, 2009 04:31 PM

Good research Diane. The Well blog also alluded to a study on marathoners. What the Gatorade survey tells me is that research on adolescent athletes on this issue is overdue.

Omie

October 21, 2009 07:02 PM

Interesting. Fortunately, I worry enough about exercising enough and hence do not have to worry about exercising too much. However, I wonder if the variable that contributes to the compromised immunity is lack of rest. So if people increased their resting period in proportion with their exercise rate, perhaps they will be just fine. But I can imagine that the amount of sleep/rest probably stayed the same or even decreased (with more exercise time cutting into it) and thus led to a decrease in immunity. Just a thought - I'll have to see the detailed study.

Korean Ginseng

November 21, 2009 07:23 AM

Thank you for sharing... It is very interesting information. Great research!!!

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In this blog, BusinessWeek’s Lauren Young, Cathy Arnst, Diane Brady, Karyn McCormack, Anne Newman, Mauro Vaisman, Lourdes L. Valeriano, and Joy Katz, Mark Hyman, along with freelance writer Savita Iyer-Ahrestani, lead a broad discussion of the issues and day-to-day concerns of working parents, offering up interviews with work/life experts, examinations of relevant research, and their personal accounts of bouncing between separate, sometimes conflicting worlds.

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