Tag Archives: exercise

What Causes Type 2 Diabetes?

“Beats me. I teach math!”

I have no simple answer for you, unfortunately.

You can lower your risk of type 2 diabetes significantly by avoiding overweight and obesity, by exercising regularly, and by choosing the right parents.  These provide clues as to the causes of diabetes.  The Mediterranean diet also prevents diabetes.

UpToDate.com offers a deceptively simple answer:

Type 2 diabetes mellitus is caused by a combination of varying degrees of insulin resistance and relative insulin deficiency. [Insulin is the pancreas hormone that lowers blood sugar.] Its occurrence most likely represents a complex interaction among many genes and environmental factors, which are different among different populations and individuals.

So, what causes the insulin resistance and relative insulin deficiency?

Understanding the pathogenesis [cause] of type 2 diabetes is complicated by several factors. Patients present with a combination of varying degrees of insulin resistance and relative insulin deficiency, and it is likely that both contribute to type 2 diabetes. Furthermore, each of the clinical features can arise through genetic or environmental influences, making it difficult to determine the exact cause in an individual patient. Moreover, hyperglycemia itself can impair pancreatic beta cell function and exacerbate insulin resistance, leading to a vicious cycle of hyperglycemia causing a worsening metabolic state.

The UpToDate article then drones on for a several thousand words discussing mouse studies, various genes, free fatty acids, adiponectin, leptin, amylin, insulin secretion, insulin resistance, impaired insulin processing, insulin action, body fat distribution, inflammation, various inflammatory markers, low birth weight, high birth rate, prematurity, etc.  More excerpts:

Increased free fatty acid levels, inflammatory cytokines from fat, and oxidative factors, have all been implicated in the pathogenesis of metabolic syndrome, type 2 diabetes, and their cardiovascular complications.

Insulin resistance may, at least in part, be related to substances secreted by adipocytes [fat cells] (“adipokines” including leptin adiponectin, tumor necrosis factor alpha, and resistin).

Type 2 diabetes most likely represents a complex interaction among many genes and environmental factors.

That’s the simplest answer I can give now.

Steve Parker, M.D.

Reference: “The Pathogensis of Type 2 Diabetes Mellitus”  by David K McCulloch, MD, and R Paul Robertson, MD, at UpToDate.com, updated June 2012, and accessed November 19, 2012.

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Six Weeks of Hillfit

Last January I wrote a favorable review of Chris Highcock’s Hillfit strength training program for hikers.  A few months ago I actually followed the the program for six weeks, and I still like it.  It’s an eye-opener.

See my prior review for details of the program.  Briefly, you do four exercises (requiring no special equipment) for fifteen minutes twice a week.  Who doesn’t have time for that?

Wanna arm wrestle?

I did modify the program a bit.  I included high-intensity intervals on a treadmill twice weekly, right after my Hillfit exercises.  Here’s the 15-minute treadmill workout: 3 minute warm-up at 5.3 mph, then one minute fast jogging at 7–8 mph, then one minute of easy jog at 5.3 mpg. Alternate fast and slow running like that for 6 cycles.  So my total workout time was 30 minutes twice weekly.

Why the treadmill HIIT (high intensity interval training)?  For endurance.  I’m still not convinced that strength training alone is adequate for the degree of muscular and cardiopulmonary endurance I want.  I’m not saying it isn’t adequate.  That’s a self-experiment for another day.  In 2013, I’m planning to hike Arizona’a Grand Canyon rim to rim with my son’s Boy Scout troop.  That’s six or eight miles down, sleep-over, then six or eight  miles back up the other side of the canyon.  That takes strength and endurance.

One part of the program I wasn’t good at: Chris recommends taking about 10 seconds to complete each exercise motion.  For example, if you’re doing a push-up, take 10 seconds to go down to the horizontal position, and 10 seconds to return up to starting position with arms fully extended.  I forgot to do it that slowly, taking five or six seconds each way instead.

I’ve preached about the benefits of baseline and periodic fitness measurements.  Here are mine, before and after six weeks of Hillfit and treadmill HIIT:

  • weight: no real change (168 lb or 76.2 kg rose to 170 lb or 77.3 kg)
  • body mass index: no change (23.3)
  • resting heart rate and blood pressure: not done
  • maximum consecutive push-ups: 30 before, 34 after
  • maximum consecutive pull-ups: 7 before, 8 after
  • maximum consecutive sit-ups: 30 before, 37 after
  • time for one-mile walk/run: 8 minutes and 45 seconds before, down to 8 minutes and 35 seconds after
  • vertical jump (highest point above ground I can jump and touch): 108.75 inches or 276 cm before, to 279.5 cm after
  • waist circumference: no real change (92 cm standing/87 cm supine before, 92.5 cm standing/87.5 cm supine after)
  • biceps circumference: no real change (33 cm left and 33.5 cm right before; 33 cm left and 33 cm right after)
  • calf circumference: 39.5 cm left and 39 cm right, before; 38.5 cm left and 37 cm right, after (not the same child measuring me both times)
  • toe touch (stand and lock knees, bend over at waist to touch toes: 7.5 inches (19 cm) above ground before, 8.5 inches (22 cm) after

If these performance numbers seem puny to you, please note that I’m 57-years-old.  I’m not sure exactly where I stand among others my age, but I suspect I’m in the top half.  I’m fit enough to be in the U.S. Army (I’m not in it, however).  I’m sure I could do much better if I put in the time and effort.  My goal right now is to achieve or maintain a reasonable level of fitness without the five hours a week of exercise recommended by so may public health authorities.

Take-Home Points

Overall, this program improved my level of fitness over six weeks, with a minimal time commitment.  I credit Hillfit for the gains in push-ups, pull-ups, sit-ups, and perhaps vertical jump.

My time on the one-mile run didn’t improve much, if at all.  This fits with my preconceived notion that strength training might not help me with leg muscle  and cardiopulmonary endurance.

The Hillfit exercise progressions involve adding weights to a backpack (aka rucksack or knapsack) before you start the exercise.  I’m already up to 80 lb (36 kg) extra weight on the modified row, and 85 lb (39 kg) on the hip extensions.  That’s getting unwieldy and straining the seams of my backpack.  I can’t see going much higher with those weights.

I expect I could easily maintain my current level of fitness by continuing Hillfit and HIIT treadmill work at my current levels of intensity.  In only one hour per week.  Not bad at all.

It’s possible I could get even stronger if I stuck to the program longer, or slowed down my movements to the recommended 10 seconds each way.

The key to muscle strength gain with Hillfit seems to be working the muscles steadily, to near-exhaustion over 90 seconds, gradually adding a higher work load as the days or weeks pass.

I’m setting Hillfit aside for now, only because I want to start a new self-experiment.

Hillfit is an excellent time-efficient strength training program for those with little resistance-training background, or for those at low to moderate levels of current fitness.

Steve Parker, M.D.

Note to self:

When doing a mile run on the treadmill, I tend to start out too fast, then burn out and have to slow down.  That may be impairing my performance.  Next time, start at 7 mph for a couple minutes then try to increase speed.  Running a mile at 7 mph takes nine minutes.  A mile at 7.5 mph takes 8 minutes.  A mile at 8 mph takes 7 minutes and 30 seconds.

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What Are the Best Exercises?

Thanks to Meredith @HIITMama for bringing this Whole9 project to my attention:

We brought together 12 fitness experts from a broad range of backgrounds–with bodies of experience ranging from weightlifting to track and field to mixed martial arts, and over two centuries of collective coaching experience–to ask them all the same question:

If you could only perform five exercise movements for the rest of your life, which five would you do? (Assuming your goals are general health, fitness and longevity, and not a specialized sport)*.

The answers may surprise you.

If you want an effective and time-efficient fitness program, I’d review this series carefully.  You may have to research some terms like Turkish get-ups, farmer carries, and dips.  Find examples at YouTube.

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Random Thoughts on Fitness

A couple years ago, I was thinking about putting together a fitness program for myself.  My goals were endurance, strength, less low-back aching, flexibility, longevity, and being able to get on my horse bareback without a mounting block or other cheat.

I spent quite a bit of time at Doug Robb’s HeathHabits site.  He has a post called The “I don’t have time to workout” Workout.  I ran across some paper notes I made during my time there.  Doug recommended some basic moves to incorporate: air squat, Hindu pushup, dragon flag, shuffle of scissor lung, Spiderman lung, hip thrust/bridge, swing snatch, dumbbell press, Siff lunge, jumping Bulgarian squat, band wood chops, leg stiff leg deadlift.  Click the link to see videos of most of these exercises.  The rest you can find on YouTube.

Another post is called “Do you wanna get big and strong? -Phase 1”.  The basic program is lifting weights thrice weekly.  Monday, work the chest and back.  Tuesday, legs and abs/core.  Friday, arms and shoulders.

  • Chest exercises: presses (barbell or dumbell, incline, decline, flat, even pushups with additional resistance  – your choice
  • Back: chins or rows
  • Legs: squats or deadlifts
  • Arms and shoulders: dips, presses, curls

Doug is a personal trainer with a huge amount of experience.  He’s a good writer, too, and gives away a wealth of information at his website.

Around this same time of searching a couple years ago, I ran across Mark Verstegen’s Core Performance, Mark Lauren’s book “You Are Your Own Gym,”  and Mark Sisson’s free fitness ebook that also  features bodyweight exercises.  I did Core Performance religiously for 15 weeks—it’s a good program, requiring 5-6 hours a week.

Lauren is or was a Navy Seal trainer.  His plan involves 30 minutes of work on four days a week and uses minimal equipment.  Lots of good reviews at Amazon.com.

I recently complete a stint with the Hillfit program.  Here’s my current regimen.

Newbies to vigorous exercise should seriously consider using a personal trainer.

Steve Parker, M.D.

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Is Heavy Exercise a Reasonable Approach to Obese Diabetes?

Women DO NOT get gross bulky muscles from resistance training

With regards to TV’s “The Biggest Loser” show:

The show’s 24-week regimen consists of approximately 4 hours of daily exercise, including 1 hour of intense resistance, 1 hour of intense aerobic activity, and 2 hours of moderate aerobic activity (for example, walking), along with a caloric  intake of at least 70% of estimated resting daily energy expenditure, explained Dr. [Robert] Huizenga, who is a a former team physician to the L.A. Raiders football team.

This is an excerpt from “The Biggest Loser Pushes Envelope on Diabetes,” in Internal Medicine News, vol. 45, No.11, page 17.

In a previous post about The Biggest Loser, I’d written that I didn’t know how much they exercised.

For purposes of discussion, let’s assume the documented major weight losses of Biggest Loser contestants are not simply due to caloric restriction.

Dr. Huizenga shared some of his experience at the recent annual meeting of the American Association of Clinical Endocrinologists.  In a study of 35 Biggest Loser participants, about half had prediabetes or type 2 diabetes.  Hemoglobin A1c, a measure of blood sugar control, fell significantly in this subset.  Three of the six with diabetes were able to stop metformin early on.  By week 29 of the study, average body mass index for the entire group had fallen from 46 to 29.

Sure, this is a small study, but my clinical intuition is that results are reproducible on a larger scale.  Television exposure and the $250,000 (USD) prize to the winning contestant are major motivators.  Furthermore, I bet there’s also a process for weeding out those who are likely to fail, before they ever get started.

Yes, exercise helps with weight loss.  But most folks aren’t willing or able to exercise vigorously for almost four hour daily.  If I were an obese sedentary diabetic, I’d sure try.

Steve Parker, M.D.

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U.S. Army Physical Fitness Requirements: Are You As Strong As a Soldier?

I’ve written previously how it’s helpful to have some baseline physical fitness measurements on yourself. That post mentioned up to 14 different items you could monitor. In the comment section, I recognized that’s too much for some folks. For them, I suggested just doing the five-item functional testing: 1-mile run/walk (timed), maximum number of push-ups and pull-ups, toe touch, and vertical jump.

A few months ago, I was at a training session for adult Boy Scout leaders. One of the items covered was environmental heat illness: how to avoid, recognize, and treat. One of the risk factors for heat illness is “poor fitness,” defined as taking over 16 minutes to run two miles. Inquiring minds want to know where that number came from. No reference was given.

About.com has an article on fitness requirements for U.S. army soldiers, who are tested at least twice yearly. There are only three components tested:

  • Number of push-ups
  • Number of sit-ups
  • Time to complete a two-mile run

Fortunately, the Army doesn’t expect a 57-year-old man to perform as well as a 17-year-old. For instance, a 17-year-old has to run two miles in 19 minutes and 24 seconds or less; the 57-year-old is allowed up to 23 minutes and 24 seconds. Females and males have different performance standards: a 17-year-old woman has 22 minutes and 24 seconds to run two miles.

(An ex-Ranger a few days ago told me the Rangers have to meet or exceed the standard for 19-year-olds, regardless of age.)

The simplicity of the Army’s approach appeals to me. Check out the APFT tables in the About.com article if you want to see how you compare to Army soldiers.

Steve Parker, M.D.

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Starting a Fitness Program? Get Baseline Measurements First

Impressive jump!

Before beginning or modifying a fitness program, it’s helpful to take some baseline physical measurements. Re-measure periodically. That way you’ll know whether you’re making progress, holding steady, or regressing. Improving your numbers also helps to maintain motivation.

Not taking measurements would be like starting a weight loss plan without a baseline and subsequent weights.

Eighteen months ago, I finished a home-based, 15-week, six-days-a-week fitness program called Core Performance, designed by Mark Verstegen. I was pleased with the results. The only problem is that it’s very time-consuming, 45-60 minutes a day. Perhaps fitness just has to be that way.

I regret that I didn’t take any fitness measurements before and after starting Core Performance.

For much of the last year, I modified Core Performance to a thrice weekly, then twice weekly program, until a couple months ago when I pretty much abandoned it. I miss the benefits now, but just didn’t want to put in the time to achieve them. In other words, I lost my motivation.

Who needs this much flexibility?

Intellectually, I know that regular exercise is important. I’ve read that you can be fairly fit with as little as 30 minutes of exercise a week. I’m not entirely convinced yet. I’ll be test-driving some of these time-efficient programs over the next 12 months.  One I’ve done already is Hillfit.

This new style of fitness is promoted by the likes of Dr. Doug McGuff, Chris Highcock, Skyler Tanner, Nassim Taleb, and Jonathan Bailor, among others.

What to Measure

  1. Weight
  2. Blood pressure
  3. Resting heart rate (first thing in the AM before getting out of bed)
  4. Waist circumference (upright and supine)
  5. Height
  6. Body mass index
  7. Mid-arm circumference, both arms, hanging relaxed at your sides
  8. Maximal calf circumference, both calves, while standing at ease
  9. Maximum number of consecutive pull-ups
  10. Maximum number of consecutive push-ups
  11. Run/walk one mile as fast as you can
  12. Maximum vertical jump (stand by a tall wall then jump and reach up as high as you can with one arm, noting the highest point above ground your fingers can reach)
  13. Can you touch your toes? Stand up straight, locking knees in extension, then bend over at your waist and touch your toes with your fingertips. If you can touch toes, can you flatten your palms against the floor? If you can’t reach your toes, measure the distance from your fingertips to the floor.
  14. Optional blood work for special situations: fasting blood sugar, hemoglobin A1c, triglycerides, cholesterols (total, HDL, LDL, sub-fractions)

The particular aspects of fitness these measure are strength and endurance in major muscle groups, cardiovascular and pulmonary endurance, a little flexibility, and a hint of body composition.

You may appreciate an assistant to help you measure some of these.

It’a long list.  If too long, just do what you think is important.  Record your numbers. Re-test some or all of these periodically, such as every six weeks after making a change.

If you’re in fairly poor condition at the outset, you’ll see some improved numbers after a couple or three weeks of a good exercise program. It takes months to build significant muscle mass; you’ll see improved strength and endurance before mass.

Am I missing anything?

Steve Parker, M.D.

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What Everybody Ought to Know About Exercise’ Effect on Weight

  • Your genetics largely determines your response to an exercise program
  • Physical activity isn’t a great way to lose weight
  • School-based or other programs to increase childhood physical activity probably won’t reverse childhood obesity statistics
  • Disregarding weight loss, exercise has other worthwhile metabolic advantages
  • Highly advanced societies shouldn’t blame our overweight problem on decreased levels of physical activity

Skyler Tanner slaughters some sacred cows in his blog post June 4, 2012. I pulled these bullet points from his post. Click on his embedded links for details.

Steve Parker, M.D.

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TV’s Biggest Loser Plan Improves Diabetes and Prediabetes

TV’s “The Biggest Loser” weight-loss program works great for overweight diabetics and pre diabetics, according to an article May 30, 2012, in MedPage Today.  Some quotes:

For example, one man with a hemoglobin A1c (HbA1c) of 9.1, a body mass index (BMI) of 51, and who needed six insulin injections a day as well as other multiple prescriptions was off all medication by week 3, said Robert Huizenga, MD, the medical advisor for the TV show.

In addition, the mean percentage of weight loss of the 35 contestants in the study was 3.7% at week 1, 14.3% at week 5, and 31.9% at week 24…

The exercise regimen for those appearing on “The Biggest Loser” comprised about 4 hours of daily exercise: 1 hour of intense resistance training, 1 hour of intense aerobics, and 2 hours of moderate aerobics.

Caloric intake was at least 70% of the estimated resting daily energy expenditure, Huizenga said.

At the end of the program, participants are told to exercise for 90 minutes a day for the rest of their lives. Huizenga said he is often told by those listening to him that a daily 90-minute exercise regimen is impossible because everyone has such busy lives.

“I have a job and I work out from 90 to 100 minutes per day,” he said. “It’s about setting priorities. Time is not the issue; priorities are the issue.”

Of the 35 participants in this study, 12 had prediabetes and six had diabetes.  This is a small pilot study, then.  I bet the results would be reproducible on a larger scale IF all conditions of the TV program are in place.  Of course, that’s not very realistic.  A chance to win $250,000 (USD) is strong motivation for lifestyle change.

Steve Parker, M.D.

PS: Although not mentioned in the article, these must have been type 2 diabetics, not type 1.

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Do Calcium Supplements Cause Heart Attacks?

A new European study suggests that calcium supplements almost double the risk of having a heart attack, at least in Germans.  You can read the full report in the current issue of Heart.

The medical literature on this issue is a confusing mess.  In other words, lots of conflicting results.

Huge numbers of women in the U.S. are taking calcium supplements either to treat or prevent osteoporosis and the associated broken bones (e.g., hips, wrists, spine).

What I’d like to know, and what nobody knows, is what is the effect of calcium supplementation on average longevity and quality of life.  Maybe I’d accept a higher risk of heart attack if calcium supplementation prolonged lifespan by two years.

In the interest of brevity, I’ll just say that the best way to get your calcium is probably through food rather than supplements.

Shereen Jegtvig has an article at About.com listing foods rich in calcium.

Exercise can also help keep your bones strong and break-resistant.

Steve Parker, M.D.

PS: If your doctor has you on a calcium supplement, you’d best get his blessing before you stop it.

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