Tag Archives: exercise

Book Review: “Stop the Clock: The Optimal Anti-Aging Strategy”

dementia, memory loss, Mediterranean diet, low-carb diet, glycemic index, dementia memory loss

“I wish we could have read PD Mangan’s book thirty years ago!”

I read P.D. Mangan’s 2015 book, Stop the Clock: The Optimal Anti-Aging Strategy. I give it five stars in Amazon’s rating system. High recommended.

♦   ♦   ♦

I approached this book with trepidation. I like PD Mangan even though I’ve never met him. We’ve interacted on Twitter and at our blogs. You can tell from his blogging that he’s very intelligent. I don’t know his educational background but wouldn’t be surprised if he has a doctorate degree. My apprehension about the book is that I was concerned it would be brimming with malarkey and scams. Fortunately, that’s not the case at all.

Twin studies have established that 25% of longevity is genetic. That leaves a lot of lifestyle factors for us to manipulate.

I’m not familiar with the anti-aging scientific literature and don’t expect it will ever be something I’ll spend much time on. But it’s an important topic. I’ll listen to what other smart analysts—like Mr. Mangan—have to say about it.

It’s quite difficult to do rigorous testing of anti-aging strategies on free-living humans. So the best studies we have were done with worms, rodents, and monkeys; the findings may or may not apply to us. For example, long-term calorie restriction—about 30% below expected energy needs—is known to prolong life span in certain worms and rodents, with mixed results in rhesus monkeys. It’s the rare person who would follow such a low-calorie diet for years as an experiment. I doubt I would do it even if proven to give me an extra five years of life. I like to eat.

There are several prominent theories of how and why animals age. The author thinks the major factors are:

  1. oxidative stress
  2. inflammation
  3. a decline in autophagy (perhaps most important)

An effective anti-aging program should address these issues.

In the anti-aging chapter of his book, The South Asian Health Solution, internist Ronesh Sinha says that “Lifestyle practices that reduce excess inflammation in the body will help delay the aging process.” Dr. Sinha is a huge exercise advocate and low-carb diet proponent.

Mr. Mangan makes a convincing argument that a good way to forestall aging is to apply hormetic stress. Hormesis is a phenomenon whereby a beneficial effect (e.g., improved health, stress tolerance, growth, or longevity) results from exposure to low doses of an agent or activity that is otherwise toxic or lethal when given at higher doses.

Needs a bit more hormetic stress

Needs a bit more hormetic stress

In case you’re not familiar with hormesis, here’s a major example. Lack of regular exercise leads is linked to premature death from heart disease and cancer. Starting and maintaining an exercise program leads to greater resistance to injury and disease and longer life span. On the other hand, too much exercise is harmful to health and longevity. We see that in professional athletes and excessive marathon runners. Something about exercise—in the right amount—enhances the body’s intrinsic repair mechanisms. That’s the hormetic effect of exercise; one mechanism is by turning on autophagy.

Autophagy is the body’s natural process for breaking down and removing or recycling worn-out cellular structures. This wearing-out occurs daily and at all ages.

If you’re thinking Mr. Mangan recommends exercise as an anti-aging strategy, you’re exactly right. Especially resistance training and high intensity training. His specific recommendations are perfectly in line with what I tell my patients.

Calorie restriction is another form of hormesis; the body reacts by up-regulating stress defense mechanisms. As a substitute for calorie restriction, the author recommends intermittent fasting. Intermittent fasting increases insulin sensitivity, which leads to enhanced autophagy. Fasting seems perfectly reasonable if you think about it, which very few do. Many of us eat every three or four hours while awake, whether a meal or a snack. If you think about it, that’s not a pattern that would be supported by evolution. In the Paleolithic era, we often must have gone 12–16 hours or even several days without food. Hominins without the resiliency to do that would have died off and not passed their genes down to us.

Steve Parker MD, Advanced Mediterranean DIet

Naturally low-carb Caprese salad: mozzarella cheese, tomatoes, basil, extra virgin olive oil

Another anti-aging trick is a low-carb diet, defined as under 130 grams/day, or under 20% of total calories. It may work via insulin signaling and weight control.

Glutathione within our cells is a tripeptide antioxidant critical for clearing harmful reactive oxygen species (free radicals). We need adequate glutathione to prevent or slow aging. Cysteine is the peptide that tends to limit our body’s production of glutathione. We increase our cysteine supply either through autophagy (which recycles protein peptides) or diet. Dietary sources of cysteine are proteins, especially from animal sources. Whey protein supplements and over-the-counter n-acetyl cysteine are other sources. Fasting is another trick that increases cysteine availability via autophagic recyling.

I don’t recall the author ever mentioning it, but if you hope to maximize longevity, don’t smoke. Even if it has hormetic effects. Maybe that goes without saying in 2015.

When I read a book like this, I always run across tidbits of information that I want to remember. Here are some:

  • those of us in the top third of muscular strength have a 40% lower risk of cancer (NB: you increase your strength through resistance training not aerobics)
  • exercise helps prevent cognitive decline and dementia, at least partially via enhanced autophagy
  • exercise increases brain volume (in preparing to do this review I learned that our brains after age 65 lose 7 cubic centimeters of volume yearly)
  • optimal BMI may be 20 or 21, not the 18.5-25 you’ll see elsewhere (higher BMI due to muscle mass rather than fat should not be a problem)
  • Scientist Cynthia Kenyon: “Sugar is the new tobacco.” (in terms of aging)
  • phytochemicals (from plants, by definition) activate AMPK, a cellular energy sensor that improves stress defense mechanisms and increases metabolic efficiency
  • curcumin (from the spice turmeric) activates AMPK
  • coffee promotes autophagy
  • he does not favor HGH supplementation
  • in the author’s style of intermittent fasting, you’re not reducing overall calorie intake, just bunching your calories together over a shorter time frame (e.g., all 2,500 calories over 6-8 hours instead of spread over 24)
  • mouse studies suggest that intermittent fasting could reduce risk of Alzheimer’s disease and Parkinsons disease
  • consider phytochemical supplements: curcumin, resveratrol, green tea extract
  • calorie-restriction mimetics include resveratrol, curcumin, nicotinamide, EGCG, and hydroxycitrate
  • supplemental resveratrol at 150 mg/day improved memory and cognition in humans

The author provides very specific anti-aging recommendations that could be followed by just about anyone. Read the book for details. Scientists are working feverishly to develop more effective anti-aging techniques. I look forward to a second edition of this book in three to five years.

Steve Parker, M.D.

PS: People with certain medical conditions, such as diabetics taking drugs that can cause hypoglycemia, should not do intermittent fasting without the blessing of their personal physician. If you have any question about your ability to fast safely, check with your doctor.

PPS: If you have diabetes or prediabetes and want to reduce your carbohydrate consumption, consider my Low-Carb Mediterranean Diet or Paleobetic Diet.

Yet Another Benefit of Exercise: Memory Preservation

The NYT’s Well blog has the details. The brain’s hippocampus is a critical center for memory. Alzheimers disease is associated with a gene called apo-E4. Carriers of that gene who exercise regularly have less shrinkage of the hippocampus than non-exercisers.

To PROVE that regular exercise prevents dementia-related shrinkage of the hippocampus, you’d have to force some folks to exercise and stop others who wanted to exercise. A couple years later, scan their brains and compare the two groups. That study may never be done.

Another way to preserve your memory could be to keep your fasting blood sugars closer to the lower end of the normal range, rather than the higher end. That strategy may prevent degeneration of your hippocampus and amygdala.

The Mediterranean diet also seems to prevent or forestall dementia.

Steve Parker, M.D.

QOTD: J. Stanton on Weight Loss and Exercise

Let me be clear. Exercise is not important because it burns calories! Exercise without calorie restriction is a remarkably ineffective weight loss intervention, because it usually makes us hungry enough to replace the calories we burn. Exercise is important because it restores your ability to oxidize fat—both when fasting and after meals. And we can tie this in with mitochondrial dysfunction by noting that exercise is proven to increase mitochondrial volume.

J. Stanton

Type 2 Diabetics Better Exercise as They Age

Steve Parker MD

Strength training (aka resistance training) is the way to build muscle mass and strength. Jogging’s more for cardiovascular endurance.

Compared to others, elderly type 2 diabetics are more afflicted with diminished leg muscle mass, leg strength, and functional capacity. Click for details.

The right exercise program can counteract these problems, improve quality of life, and prevent falls.

Steve Parker, M.D.

h/t Bill Lagakos

Does Stretching Prevent Sports Injuries?

No.

This is a U.S. Army-style sit-up. I do sit-ups with my arms folded across my chest, hands on my shoulders

This is a U.S. Army-style sit-up. I do sit-ups with my arms folded across my chest, hands on my shoulders

For a couple years I’ve thought that stretching didn’t prevent injuries. Now I’ve got a scientific reference to back up my contention. Also from the abstract:

Strength training reduced sports injuries to less than 1/3 and overuse injuries could be almost halved.

h/t James Steele II

Advice to New Muscleheads from Lou Schuler

Steve Parker MD, Advanced Mediterranean Diet, Ketogenic Mediterranean Diet

Not me or Mr. Schuler

I was glad to see that four of my basic exercises were listed by Schuler as foundational: squat, deadlift, pushup, and row. A little more from him:

Every good training program is based on bedrock principles like progressive overload. You give your body a stimulus. You repeat the stimulus an optimal number of times. And then you give your body the opportunity to recover from it. Every good lifter eventually learns how to apply the principles in a way that works for him or her, but it always starts with the basics: learn the movements, apply the movements, build on the movements.

Every bad training program ignores these fundamentals, but it ignores them in a unique way. Too much stimulus with too little recovery. Too little stimulus with too much recovery. Poor exercise selection for the individual’s abilities and goals.

Read the whole thing.

 

h/t Yoni Freedhoff, M.D.

Does Your Response to Physical Training Depend on Your Genes?

Steve Parker MD

Her response depends on genes, training program, nutrition, discipline, adequate sleep, adequate rest, etc.

Here’s an excerpt from an interview with author David Epstein in Outside online. Epstein wrote The Sports Gene: Inside the Science Of Extraordinary Athletic Performance:

Interviewer: That’s one of the most fascinating and unexpected parts of the book, where you discuss the Heritage study’s findings on trainability. Explain its implications.

Epstein: That’s the most famous exercise-genetics study ever done. It’s the collaboration of five colleges in the U.S. and Canada. They took sedentary, two-generation families, which didn’t have a training history, and put them through stationary-bike exercise plans that were totally controlled. Families had to go into the lab and exercise over five months. The goal was to see how people would improve, and they were split into four different university centers to do the training and every center saw the exact same pattern. About 15% of people improved their aerobic capacity very little or not at all. And 15% improved 50% or more doing identical training. Families tended to stick together in the improvement curve, so about half of any person’s improvement was determined by their parents. I remember the editorial that ran in the journal of applied physiology “some people’s alphabet soup—meaning their DNA—didn’t spell ‘runner.’” One person training the exact same as another person can have completely different outcomes.

Many folks don’t like to admit this, assuming it’s true. “Set your mind to it, work hard—10,000 hours—and you can do or be anything you want.” Have you ever been tortured by unrealistic expectations? The truth will set you free.

Read the rest.

Exercise for the Diabetic

GENERAL EXERCISE BENEFITS

Regular physical activity postpones death, mostly by its effect on cancer, strokes, and heart attacks.

Consider a personal trainer if you're not familiar with weight training

Consider a personal trainer if you’re not familiar with weight training

Exercise is a fountain of youth. Peak aerobic power (or fitness) naturally diminishes by 50 percent between young adulthood and age 65. Regular exercise increases fitness (aerobic power) by 15–20 percent in middle-aged and older men and women, the equivalent of a 10–20 year reduction in biological age.

Additional benefits of exercise include: 1) enhanced immune function, 2) stronger bones, 3) preservation and improvement of flexibility, 4) lower blood pressure by 8–10 points, 5) diminished premenstrual bloating, breast tenderness, and mood changes, 6) reduced incidence of dementia, 7) less trouble with constipation, 7) better ability to handle stress, 8) less trouble with insomnia, 9) improved self-esteem, 10) enhanced sense of well-being, with less anxiety and depression, 11) higher perceived level of energy, and 12) prevention of weight regain.

EFFECT ON DIABETES

Eighty-five percent of type 2 diabetics are overweight or obese. It’s not just a random association. Obesity contributes heavily to most cases of type 2 diabetes, particularly in those predisposed by heredity. Insulin is the key that allows bloodstream sugar (glucose) into cells for utilization as energy, thus keeping blood sugar from reaching dangerously high levels. Overweight bodies produce plenty of insulin, often more than average. The problem in overweight diabetics is that the cells are no longer sensitive to insulin’s effect. Weight loss and exercise independently return insulin sensitivity towards normal. Many diabetics can improve their condition through sensible exercise and weight management.

Muscles doing prolonged exercise soak up sugar from the blood stream to use as an energy source, a process occurring independent of insulin’s effect. On the other hand, be aware that blood sugar may rise early in the course of an exercise session.

EXERCISE RECOMMENDATIONS

You don’t have to run marathons (26.2 miles) or compete in the Ironman Triathlon to earn the health benefits of exercise. However, if health promotion and disease prevention are your goals, plan on a lifetime commitment to regular physical activity.

For the general public, the U.S. Centers for Disease Control and Prevention recommends:

  • at least 150 minutes per week of moderate-intensity aerobic activity (e.g., brisk walking) and muscle-strengthening activity at least twice a week, OR
  • 75 minutes per week of vigorous-intensity aerobic activity (e.g., running or jogging) plus muscle-strengthening activity at least twice a week. The muscle-strengthening activity should work all the major muscle groups: legs, hips, back, abdomen, chest, shoulders, arms.

I’m working on a program of combined aerobic (high intensity interval training) and strength training for just 70 minutes a week, but it’s not yet ready for prime time.

STRENGTH TRAINING

What’s “strength training”? It’s also called muscle-strengthening activity, resistance training, weight training, and resistance exercise. Examples include lifting weights, work with resistance bands, digging, shoveling, yoga, push-ups, chin-ups, and other exercises that use your body weight or other loads for resistance.

I prefer free weights over machines, but that's just me

I prefer free weights over machines, but that’s just me

Strength training just twice a week increases your strength and endurance, allows you to sculpt your body to an extent, and counteracts the loss of lean body mass (muscle) so often seen during efforts to lose excess weight. It also helps maintain your functional abilities as you age. For example, it’s a major chore for many 80-year-olds to climb a flight of stairs, carry in a bag of groceries from the car, or vacuum a house. Strength training helps maintain these abilities that youngsters take for granted.

According to the U.S. Centers for Disease Control and Prevention: “To gain health benefits, muscle-strengthening activities need to be done to the point where it’s hard for you to do another repetition without help. A repetition is one complete movement of an activity, like lifting a weight or doing a sit-up. Try to do 8–12 repetitions per activity that count as 1 set. Try to do at least 1 set of muscle-strengthening activities, but to gain even more benefits, do 2 or 3 sets.”

If this is starting to sound like Greek to you, consider instruction by a personal trainer at a local gym or health club. That’s a good investment for anyone unfamiliar with strength training, in view of its great benefits and the potential harm or waste of time from doing it wrong. Alternatives to a personal trainer would be help from an experienced friend or instructional DVD. If you’re determined to go it alone, Internet resources may help, but be careful. Consider “Growing Stronger: Strength Training for Older Adults” (ignore “older” if it doesn’t apply).

Current strength training techniques are much different than what you remember from high school 30 years ago—modern methods are better. Some of the latest research suggests that strength training may be even more beneficial than aerobic exercise.

AEROBIC ACTIVITY

“Aerobic activity” is just about anything that mostly makes you huff and puff. In other words, get short of breath to some degree. It’s also called “cardio.” Examples are brisk walking, swimming, golf (pulling a cart or carrying clubs), lawn work, painting, home repair, racket sports and table tennis, house cleaning, leisurely canoeing, jogging, bicycling, jumping rope, and skiing. The possibilities are endless. A leisurely stroll in the shopping mall doesn’t qualify, unless that makes you short of breath. Don’t laugh: that is a workout for many who are obese.

But which aerobic physical activity is best? Glad you asked!

Steve Parker MD

Not ready for this? Consider interval walking then.

Ideally, it’s an activity that’s pleasant for you. If not outright fun, it should be often enjoyable and always tolerable. Unless you agree with Ken Hutchins that exercise isn’t necessarily fun.

Your exercise of choice should also be available year-round, affordable, safe, and utilize large muscle groups. The greater mass and number of muscles used, the more calories you will burn, which is important if you’re trying to lose weight or prevent gain or regain. (Exercise isn’t a great route to weight loss in the real world, although it helps on TV’s Biggest Loser show.) Compare tennis playing with sitting in a chair squeezing a tennis ball repetitively. The tennis player burns calories much faster. Your largest muscles are in your legs, so consider walking, biking, many team sports, ski machines, jogging, treadmill, swimming, water aerobics, stationary cycling, stair-steppers, tennis, volleyball, roller-skating, rowing, jumping rope, and yard work.

Steve Parker MD

Yes, this is exercise, too

Walking is “just what the doctor ordered” for many people. It’s readily available, affordable, usually safe, and requires little instruction. If it’s too hot, too cold, or rainy outside, you can do it in a mall, gymnasium, or health club.

MEDICAL CLEARANCE  

Check this link.

SUMMARY

All I’m asking you to do is aerobic activity, such as walk briskly (3–4 mph or 4.8–6.4 km/h) for 30 minutes most days of the week, and do some muscle-strengthening exercises three times a week. These recommendations are also consistent with the American Diabetes Association’s Standards of Care–2013. This amount of exercise will get you most of the documented health benefits.

Steve Parker, M.D.

Exercise and the PWD (Person With Diabetes)

hypoglycemia, woman, rock-climbing

Hypoglycemia now would be a tad inconvenient

People with diabetes may have specific issues that need to be taken into account when exercising.

DIABETIC RETINOPATHY

Retinopathy, an eye disease caused by diabetes, increases risk of retinal detachment and bleeding into the eyeball called vitreous hemorrhage. These can cause blindness. Vigorous aerobic or resistance training may increase the odds of these serious eye complications. Patients with retinopathy may not be able to safely participate. If you have any degree of retinopathy, avoid the straining and breath-holding that is so often done during weightlifting or other forms of resistance exercise. Vigorous aerobic exercise may also pose a risk. By all means, check with your ophthalmologist first. You don’t want to experiment with your eyes.

DIABETIC FEET AND PERIPHERAL NEUROPATHY

Diabetics are prone to foot ulcers, infections, and ingrown toenails, especially if peripheral neuropathy (numbness or loss of sensation) is present. Proper foot care, including frequent inspection, is more important than usual if a diabetic exercises with her feet. Daily inspection should include the soles and in-between the toes, looking for blisters, redness, calluses, cracks, scrapes, or breaks in the skin. See your physician or podiatrist for any abnormalities. Proper footwear is important (for example, don’t crowd your toes). Dry feet should be treated with a moisturizer regularly. In cases of severe peripheral neuropathy, non-weight-bearing exercise (e.g., swimming or cycling) may be preferable. Discuss with your physician or podiatrist.

HYPOGLYCEMIA

Low blood sugars are a risk during exercise if you take diabetic medications in the following classes: insulins, sulfonylureas, meglitinides, and possibly thiazolidinediones and bromocriptine.

Hypoglycemia is very uncommon with thiazolidinediones. Bromocriptine is so new (for diabetes) that we have little experience with it; hypoglycemia is probably rare or non-existent. Diabetics treated with diet alone or other medications rarely have trouble with hypoglycemia during exercise.

Always check your blood sugar before an exercise session if you are at risk for hypoglycemia. Always have glucose tablets, such as Dextrotabs, available if you are at risk for hypoglycemia. Hold off on your exercise if your blood sugar is over 200 mg/dl (11.1 mmol/l) and you don’t feel well, because exercise has the potential to raise blood sugar even further early in the course of an exercise session.

As an exercise session continues, active muscles may soak up bloodstream glucose as an energy source, leaving less circulating glucose available for other tissues such as your brain. Vigorous exercise can reduce blood sugar levels below 60 mg/dl (3.33 mmol/l), although it’s rarely a problem in non-diabetics.

The degree of glucose removal from the bloodstream by exercising muscles depends on how much muscle is working, and how hard. Vigorous exercise by several large muscles will remove more glucose. Compare a long rowing race to a slow stroll around in the neighborhood. The rower is strenuously using large muscles in the legs, arms, and back. The rower will pull much more glucose out of circulation. Of course, other metabolic processes are working to put more glucose into circulation as exercising muscles remove it. Carbohydrate consumption and diabetic medications are going to affect this balance one way or the other.

If you are at risk for hypoglycemia, check your blood sugar before your exercise session. If under 90 mg/dl (5.0 mmol/l), eat a meal or chew some glucose tablets to prevent exercise-induced hypoglycemia. Re-test your blood sugar 30–60 minutes later, before you exercise, to be sure it’s over 90 mg/dl (5.0 mmol/l). The peak effect of the glucose tablets will be 30–60 minutes later. If the exercise session is long or strenuous, you may need to chew glucose tablets every 15–30 minutes. If you don’t have glucose tablets, keep a carbohydrate source with you or nearby in case you develop hypoglycemia during exercise.

Re-check your blood sugar 30–60 minutes after exercise since it may tend to go too low.

If you are at risk of hypoglycemia and performing moderately vigorous or strenuous exercise, you may need to check your blood sugar every 15–30 minutes during exercise sessions until you have established a predictable pattern. Reduce the frequency once you’re convinced that hypoglycemia won’t occur. Return to frequent blood sugar checks when your diet or exercise routine changes.

These general guidelines don’t apply across the board to each and every diabetic. Our metabolisms are all different. The best way to see what effect diet and exercise will have on your glucose levels is to monitor them with your home glucose measuring device, especially if you are new to exercise or you work out vigorously. You can pause during your exercise routine and check a glucose level, particularly if you don’t feel well. Carbohydrate or calorie restriction combined with a moderately strenuous or vigorous exercise program may necessitate a 50 percent or more reduction in your insulin, sulfonylurea, or meglitinide. Or the dosage may need to be reduced only on days of heavy workouts. Again, enlist the help of your personal physician, dietitian, diabetes nurse educator, and home glucose monitor.

Finally, insulin users should be aware that insulin injected over muscles that are about to be exercised may get faster absorption into the bloodstream. Blood sugar may then fall rapidly and too low. For example, injecting into the thigh and then going for a run may cause a more pronounced insulin effect compared to injection into the abdomen or arm.

medical clearance, treadmill stress test

This treadmill stress test is looking for hidden heart disease

AUTONOMIC NEUROPATHY

This issue is pretty technical and pertains to function of automatic, unconscious body functions controlled by nerves. These reflexes can be abnormal, particularly in someone who’s had diabetes for many years, and are called autonomic neuropathy. Take your heart rate, for example. It’s there all the time, you don’t have to think about it. If you run to catch a bus or climb two flights of stairs, your heart rate increases automatically to supply more blood to exercising muscles. If that automatic reflex doesn’t work properly, exercise is more dangerous, possibly leading to passing out, dizziness, and poor exercise tolerance. Other automatic nerve systems control our body temperature regulation (exercise may overheat you), stomach emptying (your blood sugar may go too low), and blood pressure (it could drop too low). Only your doctor can tell for sure if you have autonomic neuropathy.

Steve Parker, M.D.

But, Doc, My Back and Joints Hurt Too Much To Exercise!

EXERCISE WITH JOINT AND BACK PAIN

Many of my obese patients have chronic low back and joint pains.  Painful lower limb joints and chronic or recurrent back pain are an exercise barrier to many people, whether skinny or fat. Those affected should consult a physician for a diagnosis, treatment, and advice on appropriate physical activity. If the physician isn’t sure about an exercise prescription, consultation with an orthopedist, physiatrist, or physical therapist should be helpful. Generally, weight-bearing on bad joints should be minimized by doing pool calisthenics, stationary cycling, swimming, etc. Use your imagination. Particularly bothersome joints may not tolerate exercise, if ever, until weight is lost by some method other than exercise. (Exercise by itself is typically an ineffective way to lose major weight.)

Light to moderate exercise actually reduces the pain and disability of knee degenerative arthritis. The effect is modest and comes with a small risk of injury such as bone fracture, cartilage tears, arthritis flare, and soft tissue strain.