Category Archives: Physical Fitness

Yep… We Really Need to Exercise

“Regular exercise of the type that elevates heart rate is the single most useful thing you can do to maintain your cognitive ability as you age.”
– Drs. Sandra Aamodt and Sam Wang

All of my life, I’ve heard the diet-and-exercise mantra for weight loss. I’ve been told that dieting alone isn’t a good idea. It makes the body think there’s a famine, so it automatically dials down its metabolic requirements to adjust for the reduced caloric intake. Exercise provides the counterbalance that forces the body to keep its metabolic fires burning. But how exactly does that work?

joggingDigital readouts on aerobic equipment draw our attention to the number of calories burned during workouts. But that’s just the tip of the iceberg. Exercise increases cellular mitochondria. These microscopic organelles generate energy by metabolizing sugars, fats, and other chemical fuels. They’re certainly on the job when I’m expending energy at the gym. But they’re also working hard in my behalf while I’m at rest. By increasing their strength and numbers, I’m burning extra calories 24 hours a day. Once I reach my ideal body mass, they give me the freedom to add healthy food to my daily diet.

Unfortunately, the bathroom scale may not reward the diet-and-exercise regimen. Lean muscle weighs more than fat. So I could easily drop inches while maintaining (or even gaining) a bit of weight. Fluid retention also confounds the readout from the bathroom scale. That’s why I like to get a full body scan on a fancy-schmancy scale periodically to get a better sense of changes in my lean muscle mass, body fat, and water weight.

Of course, my panel of experts (listed below) would be quick to remind me that diet is about weight, and exercise is about health. There are many more reasons to exercise than just slimming down:

Exercise is heart healthy. It strengthens the heart muscle while lowering plaque-forming cholesterol.

Exercise improves digestion. It puts the lid on overeating through improved leptin signaling. (Leptin tells the brain when the body is full.) It increases the liver’s Krebs cycle to help it burn energy cleaner. It improves insulin sensitivity to support fuel storage in the cells.

Exercise improves lymphatic flow. The lymphatic system disposes of cellular waste, fights infections, and helps maintain body fluids. Because it lacks its own pump (a la the heart for the circulatory system), it needs physical activity to help move things along.

Exercise promotes blood flow to the brain and fortifies neural networks. It expands the size of the memory center, spurs the generation of new brain cells, makes neurons more nimble, and supports multi-tasking abilities. Exercise is essential for healthy aging. In one study, elderly people who exercised 20 minutes per day for 24 weeks demonstrated substantially better memory, language ability, and attention than their sedentary counterparts.

Exercise reduces stress and releases endorphins. It calms the fight-or-flight response (if present) and elevates mood. It can be an effective antidote to anxiety and/or depression.

Exercise activates genes linked to longevity. It is associated with a significant uptick in telomerase, the enzymes that repair damage and stimulate growth in our telomeres. Telomeres reside at the end of our chromosomes and make sure that our DNA strands remain intact. They shorten with age and other stressors. Cells cannot reproduce when their telomeres become unsustainably short.

The experts tell us that exercise must be consistent to confer benefit. Most suggest a minimum of 30 minutes of vigorous effort several times per week. Variety improves effectiveness. For example, cross-training and high intensity interval training have been associated with greater mitochondrial production and longer telomeres. Some benefits also accrue to those who regularly participate in actions of daily living – e.g., cooking, doing dishes, cleaning, gardening.

I’m not fond of exercise, but it sure does the body, mind, and spirit good!

 

Panel of Experts:

  • Sandra Aamodt, PhD and Sam Wang, PhD – Welcome to Your Brain: Why You Lose Your Car Keys but Never Forget How to Drive and Other Puzzles of Everyday Life, ©2008
  • Elizabeth Blackburn, PhD and Elissa Epel, PhD – The Telomere Effect: A Revolutionary Approach to Living Younger, Healthier, Longer, ©2017
  • Jeffrey S. Bland, MD – The Disease Delusion: Conquering the Causes of Chronic Illness for a Healthier, Longer, Happier Life, ©2014
  • Robert H. Lustig, MD – Fat Chance: Beating the Odds Against Sugar, Processed Food, Obesity, and Disease, ©2012
  • David Perlmutter, MD – Grain Brain: The Surprising Truth About Wheat, Carbs, and Sugar – Your Brian’s Silent Killers, ©2013

Why Exercise is Good for the Brain

Most of us can recite the reasons why exercise is good for our bodies. Aerobic exercise strengthens our cardiovascular system and raises our metabolic rates. An elevated metabolism burns more calories which helps us maintain a healthy weight. Load-bearing exercise (a.k.a. “pumping iron”) builds muscles and strengthens bones. And a daily dose of vigorous exercise can help us sleep better at night. In SPARK: The Revolutionary New Science of Exercise and the Brain, Dr. John J. Ratey, MD gives us yet another reason to move. Exercise gets our brains to function at peak efficiency.

ready to learnTwo innovative school districts served as “demonstration plots” for the mind-body connection in active fitness programs. Teachers reported that when students in the Naperville IL or Titusville PA school districts completed a mile run:

  • They went to class alert, focused, and ready to learn.
  • They were less fidgety, tense, and moody.
  • They felt more motivated and invigorated.
  • They outperformed peers who did not participate in a fitness regimen.

The last point merits special attention. Naperville’s District 203 students placed among the highest echelons of students academically in the U.S. and abroad. Some dismissed these results given Naperville’s favorable socioeconomic standing (although District 203 compared favorably to schools with comparable demographics). Titusville serves an underprivileged population. Their students went from below average performance statewide to 17% above average in reading and 18% above average in math. Moreover, they experienced a near absence of fist fights. Both districts also reported very low rates of childhood obesity.

For the record, Physical Education (PE) at Naperville and Titusville isn’t the “stand around and wait your turn to bat a ball” kind of fitness. Nor is it a one-size-fits-all program. Kids are encouraged to find an activity they enjoy with the right level of effort to elevate their heart rates to their target zones. If kids like wall climbing, they climb walls (and enjoy their classmates’ cheers and encouragement while doing it). If they’re slow runners but manage to get their heart rates up, they’ll receive praise for working at their own paces.

The other end of the age spectrum also provides “demonstration plots.” Among elderly populations, those who are educated, confident in their ability to effect positive change (a.k.a. “self-efficacious”), and exercised exhibit the least cognition decline.

From this launching pad, Dr. Ratey’s book dives into the neuroscience behind the beneficial impact of exercise. Here’s a high-level summary:

  • Exercise elevates neurotransmitters (serotonin, norepinephrine, and dopamine) responsible for attention, perception, motivation, arousal, and mood.
  • Exercise elevates brain derived neurotropic factors (BDNF) that build and maintain brain circuitry. It strengthens our cellular machinery for learning.
  • Cells sprouted during exercise increase the attraction between neurons and their likelihood to “spark” (a.k.a., long term potentiation or LTP).
  • The most effective form of aerobic exercise calls upon the brain to acquire skills while we move. For example, partner dancing forces the brain to take another person into account. Aerobic classes that change up the patterns of movements also encourage “skill” development.
  • The mild stress of exercise activates genes that produce proteins to protect our brain cells against damage and disease.
  • The heart muscle secrets ANP during exercise which travels through the blood-brain barrier to create a calming effect. It’s an antidote for anxiety and panic attacks.
  • exercise is good for the brainWhile exercise and medication are both effective at treating depression, consistent exercise works better over the long run. In fact, a Duke University study found that every 50-minute installment of weekly exercise reduces the odds of being depressed by 50%.
  • Exercise tricks the brain into maintaining itself for survival despite the hormonal cues that it is aging.

Dr. Ratey’s anti-aging prescription for exercise: 60 minutes of aerobic exercise at least 4x per week; strength training at least 2x per week to build strong bones and ward off osteoporosis; and, 30 minutes of flexibility and balance exercise 2x per week. It may seem rather daunting, but your body and your brain will love you for it!