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Sunday, November 11, 2018

Two New Discoveries to Explain Why Exercise Is Good for You

Have you noticed that so many elderly people seem frail, walk slowly, and seem to lack energy? If this applies to you, noticing it is unavoidable. These problems are preventable. For 25 years, I jogged at least a mile and a half three times a week. This was crucial for helping me stop smoking. I don’t know why, except that I could not smoke and jog at the same time. Also, the 15-30 minute recovery time reminded me just how bad the smoking had been for my health.

Why did I quit jogging? The jogging messed up my joints. So, I took up swimming, but since I sink like a lead mannequin, that is just too much work. So now, I joined a gym, where I use the elliptical, treadmill, and muscle-building machines. This environment helps because I have companions in my discomfort, and occasionally I get the satisfaction of comparing myself to the few “90-pound weaklings” that show up.

We have known for many years that exercise is good for you, especially as you get older. Known benefits of exercise include:

  • Relieve stress and promote a sense of well being. (Well, at least after the soreness wears off).
  • Improve heart and cardiovascular function. (If the damage is already done, don’t expect huge improvements).
  • Lose weight. (Pushing away from the table is the best exercise for this effect).
  • Strengthens bones. (Reduces loss of bone density in old age. But high-impact exercise may damage joints).
  • Lower blood sugar and help insulin work better.
  • Help quit smoking. (Ever try to smoke while jogging? Ha!).
  • Improve mood and resist depression. (Ever heard of “runner’s high? It comes from release of endogenous opiates).
  • Releases proteins and other chemicals that improve the structure and function of your brain. (Memory ability improves too).
  • Improve your sleep. (I mean, besides making you really tired. To reduce interference from soreness, take acetaminophen before bed time).\
  • Reduce your risk of some cancers, including colon, breast, uterine, and lung cancer.

What was not as well known until recently was the effect of exercise on the immune system. Recent research indicates that exercise in older age can prevent the immune system from declining and protect people against infections. A recent study followed 125 long-distance cyclists, and found that some of those in their 80s had the immune systems of 20-year olds. Maybe this is a reason exercise can help prevent cancer.

The key indicator was the level of T-cells in the blood. T cells, named after the thymus where they first appear, are a type of white blood cell that makes antibodies. As people age, the thymus gland, located in the neck, shrinks and T-cell activity resides mostly in bone marrow. The study of cyclists revealed that they were producing the same level of T-cells as 20-year olds, whereas a comparison group of inactive older adults were producing very few. Thus, it would seem that, though not tested in this study,   physically active seniors would also respond better to vaccines than sedentary people.

The other new discovery is the importance of exercise on brain white matter integrity. White matter electrically insulates nerve fibers, which has two effects: 1) speeds communication in neural networks and 2) reduces “cross talk” among adjacent fibers. The study compared people averaging 65 who were mentally normal and those who had mild cognitive impairment, which is a risk factor for later development of Alzheimer’s Disease. In both groups, investigators measured cardiovascular function with a standard measure of heart and respiratory fitness, the VO2 Max test. They also used brain scans to measure white matter integrity. Levels of physical activity were positively associated with white matter (WM) integrity and cognitive performance in normal adults and even in patients with mild cognitive impairment.

Given all this, how much more reason do you need to get off the couch and start moving? Besides, at the end of a good workout, it feels so good to quit.

"Memory Medic's latest book is for seniors: "Improve Your Memory for a Healthy Brain. Memory Is the Canary in Your Brain's Coal Mine," available in inexpensive e-book format at  See also his recent books, "Memory Power 101" (Skyhorse), and "Mental Biology. The New Science of How the Brain and Mind Relate" (Prometheus).
Ding, Kan, et al. (2018).Cardiorespiratory fitness and white matter neuronal fiber integrity in mild cognitive impairment. Journal of Alzheimer's Disease, 61(2), 729-739.

Duggai, Niharika A. et al. (2018). Major features of immune senescence, including reduced thymic output, are ameliorated by high levels of physical activity in adulthood. Aging Cell. 8 March.