A reputed link between ALS and athletics shouldn’t deter people from exercising, including those who have the disease, experts say.
In April, neurologists at Columbia Presbyterian Medical Center in New York reported that ALS patients seen in their practice had a tendency to be slim throughout life and involved in varsity athletics during their youth (see Athletics and ALS, June 2002). In September, their study was published in Neurology.
"Thousands and thousands of slim athletes never develop ALS. Why a tiny few of them do develop ALS is still unknown," wrote the team of neurologists led by Lewis Rowland, who served as director of the Eleanor and Lou Gehrig MDA/ALS Center at Columbia from 1987 to 2000. "Nothing in our data should be construed as evidence that patients with ALS should not exercise," they emphasized.
Despite those assurances, the study has raised concerns among people with the disease. In online chat rooms and bulletin boards, many have asked whether exercise will delay the course of ALS or hasten it.
Overwork vs. disuse
Much of the concern stems from speculation that intense physical training of the kind endured by athletes might somehow stress the motor neurons, the muscle-controlling nerve cells targeted by ALS. There’s little evidence for that idea, either as a cause of ALS, or a factor in its progression.
But there’s evidence that "overworking" the motor neurons plays a role in polio, a viral disease that attacks motor neurons and causes ALS-like symptoms.
Some reports suggest that people infected with polio during the epidemic of the 1950s were likely to fare worse if they exercised during the early stages of illness. Others suggest that post-polio syndrome, a relapse of weakness many years after recovery from polio, occurs because motor neurons that survive the infection get burned out from compensating for their lost comrades.
Greg Carter, who co-directs the MDA/ALS Center at the University of Washington Medical Center in Seattle, believes that overwork weakness is a danger for people with ALS, but that it shouldn’t stop them exercising.
"You need to use common sense," says Carter, a specialist in physical medicine and rehabilitation. "I’ve had ALS patients who just want to hit the gym and beat the disease by pumping iron. You can’t do that and you may end up worse off."
Moderate exercise can prolong mobility, elevate mood, help prevent pain and improve quality of life, he says. Some research suggests that it might also help protect against oxidative stress — a buildup of oxygen-based free radicals — by stimulating the production of antioxidants naturally present in the body.
Lisa Krivickas, an assistant professor of physical medicine and rehabilitation at Harvard Medical School and Spaulding Rehabilitation Hospital in Boston, says that in ALS, disuse weakness is a potentially bigger problem than overwork weakness.
Just like anyone else, people with ALS are likely to decondition their muscles if they don’t exercise, she says. "My advice for ALS patients is to exercise moderately while their muscles are still strong … the idea being to maintain strength before you lose motor neurons."
Do it, just don’t overdo it
So, what kinds of exercise are appropriate for people with ALS?
For those who are still ambulatory, Carter recommends walking, swimming and stationary bicycling. Real bicycling or any other activity that involves a serious risk of falling should be avoided, he says.
In a study published last year in the Journal of Neurological Sciences, scientists at Tel Aviv Sourasky Medical Center in Israel studied the benefits of moderate aerobic exercise in 25 people with ALS.
About half the study participants were assigned a daily exercise program of walking, stationary bicycling or swimming for 30 minutes or less, and the other half were told not to exert themselves beyond their usual daily requirements.
After three months, the exercise group scored better on measures of general function and spasticity (muscle spasms) than the control group.
Excessive "pumping iron" aside, light weightlifting can be safe and beneficial for people with ALS, Krivickas says.
"There are not well-controlled scientific studies of strength training in people with ALS. But studies of people with more slowly progressive neuromuscular diseases suggest that strength training is not harmful, as long as you avoid high resistance and eccentric [lengthening] contractions," she says.
"If you’re doing curls to work out your biceps, the eccentric phase is when you bring the weight down from your shoulder," she explains. Lowering the weight slowly and prolonging that phase, as body builders sometimes do, will probably cause more harm than good for someone with ALS, she says.
Krivickas gives regular consultations at the MDA/ALS Center at Massachusetts General Hospital in Boston.
"I tell patients if you want to go to the gym, pick a weight where you can do 20 repetitions, but don’t do 20 in a row. Do 10 to 12 so it’s a submaximal weight."
If you feel weak for more than 20 minutes after exercise, you’re overdoing it, she says.
The most important rule to follow when exercising, Krivickas and Carter say, is to establish a program that’s individualized to your needs and abilities.
Don’t push yourself too hard, avoid exercises that pose an obvious risk of injury, and work closely with a rehabilitation specialist or physical therapist who can recommend adjustments to your program as your abilities change.