Tag Archives: resistance training

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.

Resistance Versus Aerobic Training: Which Is Better?

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Weight training, also known as resistance training, may be just as effective as, or even superior to, aerobic training in terms of overall health promotion.  Furthermore, it’s less time-consuming according to a 2010 review by Stuart Phillips and Richard Winett.

I don’t like to exercise but I want the health benefits.  So I look for ways to get it done quickly and safely.

Here’s a quote from Phillips and Winett:

A central tenet of this review is that the dogmatic dichotomy of resistance training as being muscle and strength building with little or no value in promoting cardiometabolic health and aerobic training as endurance promoting and cardioprotective, respectively, largely is incorrect.

Over the last few years (decade?), a new exercise model has emerged.  It’s simply intense resistance training for 15–20 minutes twice a week.  It’s not fun, but you’re done and can move on to other things you enjoy.  None of this three to five hours a week of exercise some recommend.  We have no consensus on whether the new model is as healthy as the old.

More tidbits from Phillips and Winett:

  • they hypothesize that resistance training (RT) leads to improved physical function, fewer falls, lower risk for disability, and potentially longer life span
  • only 10–15% of middle-aged or older adults in the U.S. practice RT whereas 35% engage in aerobic training (AT) or physical activity to meet minimal guidelines
  • they propose RT protocols that are brief, simple, and feasible
  • twice weekly training may be all that’s necessary
  • RT has a beneficial effect on LDL cholesterol and tends to increase HDL cholesterol, comparable to effects seen with AT
  • blood pressure reductions with RT are comparable to those seen with AT (6 mmHg systolic, almost 5 mmHg diastolic)
  • RT improves glucose regulation and insulin activity in those with diabetes and prediabetes
  • effort is a key component of the RT stimulus: voluntary fatigue is the goal (referred to as “momentary muscular failure” in some of my other posts)
  • “In intrinsic RT, the focus and goal are to target and fatigue muscle groups.  A wide range of repetitions and time under tension can be used to achieve such a goal.  Resistance simply is a vehicle to produce fatigue and only is adjusted when fatigue is not reached within the designated number of repetitions and time under tension.”

Our thesis is that an intrinsically oriented (i.e., guided by a high degree of effort intrinsic to each subject) program with at minimum of one set with 10–15 multiple muscle group exercises (e.g., leg press, chest press, pulldown, overhead press) executed with good form would be highly effective from a public health perspective.

The authors cite 60 other sources to support their contentions.

These ideas are the foundation of time-efficient resistance training of the sort promoted by Dr. Doug McGuff, Skyler Tanner, Fred Hahn, Chris Highcock, James Steele II, and Jonathan Bailor, to name a few.

Only a minority will ever exercise as much as the public health authorities recommend.  This new training model has real potential to help the rest of us.

For folks with diabetes, the combination of aerobic and resistance training may be better than either alone, for control of glucose levels.

Steve Parker, M.D.

Reference:  Phillips, Stuart and Winett, Richard.  Uncomplicated resistance training and health-related outcomes: Evidence for a public health mandate.  Current Sports Medicine Reports, 2010, vol. 9 (#4), pages 208-213.

Exercise To Momentary Muscular Failure and You Can Skip the Cardio?

I was planning to review here an article, Resistance Training to Momentary Muscular Failure Improves Cardiovascular Fitness in Humans: A review of acute physiological responses and chronic physiological adaptations.  It’s by James Steele, et al, in the Journal of Exercise Physiology (Vol. 15, No. 3, June  2012).

But dayum, it’s too technical for me!  Too much cell biology and cell metabolism.  Those college classes were over three decades ago for me.

I’m just going to harvest a few pearls from the article that are important to me.  I ran across this in my quest for efficient exercise.  By efficient, I mean minimal time involved, yet good results.

The authors question the widespread assumption that aerobic and endurance training are necessary for development of cardiovascular fitness.  Like Dr. Doug McGuff, they wonder if resistance training alone is adequate for the development of cardiovascular fitness.  Their paper is a review of the scientific literature.  The authors say the literature is hampered by an inappropriate definition and control of resistance training intensity.  The only accurate measure of intensity, in their view, is when the participant reaches maximal effort or momentary muscular failure.

The authors, by the way, define cardiovascular fitness in terms of maximum oxygen consumption, economy of movement, and lactate threshold.

“It would appear that the most important variable with regards to producing improvement in cardiovascular fitness via resistance training is intensity [i.e., to muscle failure].”

The key to improving cardiovascular fitness with resistance training is high-intensity.  These workouts are not what you’d call fun.

"MMF? Yeah, I know all about it."

“MMF? Yeah, I know all about it.”

From a molecular viewpoint, “the adenosine monophosphate–activated protein kinase pathway (AMPK) is held as the key instigator of endurance adaptations in skeletal muscle.  Contrastingly, the mammalian target of rapamycin pathway (mTOR) induces a cascade of events leading to increased muscle protein synthesis (i.e.,[muscle] hypertrophy).”  Some studies suggest AMPK is an acute inhibitor of mTOR activation.  Others indicate that “resistance training to  failure should result in activation of AMPK through these processes, as well as the subsequent delayed activation of mTOR, which presents a molecular mechanism by which resistance training can produce improvement in cardiovascular fitness, strength, and hypertrophy.”

You’re not still with me, are you?

“… the acute metabolic and molecular responses to resistance training performed to failure appear not to differ from traditional endurance or aerobic training when intensity is appropriately controlled.”

Chronic resistance training to failure induces a reduction in type IIx muscle fiber phenotype and an increase in type I and IIa fibers.  (Click for Wikipedia article on skeletal muscle fiber types.)

“It is very likely that people who are either untrained or not involved in organized sporting competition, but you have the desire to improve their cardiovascular fitness may find value in resistance training performed to failure.  In fact, this review suggests that resistance training to failure can produce cardiovascular fitness effects while simultaneously producing improvements in strength, power, and other health and fitness variables. This would present an efficient investment of time as the person would not have to perform several independent training programs for differing aspects of fitness.”  [These statements may not apply to trained athletes.]

Before listing their 157 references, the authors note:

“It is beyond the scope of this review to suggest optimal means of employing resistance training (i.e., load, set volume, and/or frequency) in order to improve cardiovascular fitness since there are no published studies on this topic.”

In conclusion, if you’re going to do resistance training but not traditional aerobic/cardio exercise, you may not be missing out on any health benefits if you train with intensity.  And you’ll be done quicker.

Steve Parker, M.D.

PS: See Evidence-based resistance training recommendations by Fisher, Steele, et al.

QOTD: All You Need Is a Single Set of Reps

We recommend that appreciably the same muscular strength and endurance adaptations can be attained by performing a single set of ~8-12 repetitions to momentary muscular failure, at a repetition duration that maintains muscular tension throughout the entire range of motion, for most major muscle groups once or twice each week. All resistance types (e.g. free-weights, resistance machines, bodyweight, etc.) show potential for increases in strength, with no significant difference between them, although resistance machines appear to pose a lower risk of injury.

Fisher, James, et al. Evidence-based resistance training recommendations. Medicina Sportiva, 15 (2011): 147-162.

Is Your Strength Training Regimen Outdated?

Not Chris Highcock

I’m reading Hillfit: Stength, an ebook  by Chris Highcock of Conditioning Research.  One of the scientific review articles he cites in support of his recommendations is an eye-opener.

Evidence-Based Resistance Training Recommendations is available free online.  It’s published in Medicina Sportiva, which I’m not familiar with.  I’ll confess I’ve read little of the hard-core literature on the science of strength training.  It’s one of my more recent interests.

An excerpt:

We recommend that appreciably the same muscular strength and endurance adaptations can be attained by performing a single set of ~8-12 repetitions to momentary muscular failure, at a repetition duration that maintains muscular tension throughout the entire range of motion, for most major muscle groups once or twice each week. All resistance types (e.g. free-weights, resistance machines, bodyweight, etc.) show potential for increases in strength, with no significant difference between them, although resistance machines appear to pose a lower risk of injury.

The article has already got me questioning some of my notions, such as how often to work out, number of reps moving a weight, speed of moving a weight, and whether I should stick with free weights.  Why not see if your dogma is supported?  Worth a look.

Steve Parker, M.D.

Fisher, James, et al.  Evidence-based resistance training recommendations.  Medicina Sportiva, 15 (2011): 147-162.