Intense Exercise and Polio Survivors
Question: I saw this article: Motor Neurone Disease: Intense exercise increases risk. Does it apply to polio survivors exercising and causing muscle weakness?
Dr. Bruno’s Response: I think so! Read about Gary and the finding that motor neuron diseases, like ALS, are more common in professional athletes.
From The Polio Paradox . . .
“After I recovered from the polio I had when I was three I refused to use a wheelchair or braces, even though my legs were weak. The way I looked was important to me. Physical strength was important too. So a few years back, I began to power lift. I would spend three days a week doing 500 lb. leg presses at the gym thinking I would make my legs stronger and keep them strong. My legs got weaker. I fell down a flight of stairs and had two surgeries to fix torn ligaments in my feet. Four months later I fell in the shower and broke three toes. I stopped lifting and started using crutches outside my house. I thought if I just kept walking I'd get stronger. I didn't.”
Gary, Polio Class of '48
For polio survivors like Gary it is deja vu all over again. For no apparent reason his muscles were becoming weaker. Muscles he had worked so hard to make strong, muscles that had allowed him to be "normal" for decades, were failing him. In our 1985 Survey over 80% of polio survivors reported weakness in muscles paralyzed or weakened during their original bout with polio.
Unexpectedly, nearly half of the polio survivors surveyed reported weakness in muscles that seemed to have been unaffected by polio. And over 90% of polio survivors in the 1985 Survey reported that muscle weakness was triggered by physical overexertion and exercise, as Gary's experience shows. Individuals like Gary, who "pushed themselves beyond the competence" of their polio-damaged neurons, were most likely to develop weakness later in life.
Death of a Neuron. Polio survivors are getting weaker because their motor neurons are browning out, blacking out, breaking up and dying. Yes, neurons are dying. Why? Probably because polio-damaged neurons have been severely overworked, having "pumped iron" in one way or another for decades.
Given that physical overexertion is the most common trigger for muscle weakness in polio survivors, neurophysiologist Alan McComas believes that it is the combination of over-sprouting, overworking and reduced protein manufacturing that conspire to prematurely kill off poliovirus-damaged motor neurons.
What's more McComas points out that it may not be a coincidence that motor neurons fail and die more frequently in athletes like Gary. McComas found that motor neuron disease, e.g., ALS, is more common in professional athletes. But Gary isn't the only polio survivor athlete. Given what the poliovirus did to the spinal cord, the amazing extent to which polio survivors' motor neurons compensated for the damage and degree to which polio survivors have recovered strength and then overused their muscles, all polio survivors have been athletes since they had polio!