Tag Archives: momentary muscular failure

Resistance Versus Aerobic Training

Posted on January 15, 2013 | 1 comment

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Resistance or weight training may be just as effective as, or even superior to, aerobic training in terms of overall health promotion.  Plus, 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:

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.

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.

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Momentary Muscular Failure and Resistance Training

Posted on November 19, 2012 | 2 comments

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).

Exercise to momentary muscular failure may be safer on a machine

But it’s too technical for most of my readers. Heck, it’s too technical for me!  Too much cell biology and cell metabolism.  You’re dismissed now.  Maybe “American Idol” or “Honey Boo Boo” is on TV.

I’m just going to pull out 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.

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.

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 sooner.

Steve Parker, M.D.

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

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