Category Archives: Individual controls aging

Aging is driven by individual lifestyle choices.

Insight 3: Ways to retard skeletal muscle aging

Exercise, Individual controls aging, , , ,

Regular Progressive Resistance Training is the answer

So what can the older adult do to assure continued independence, normal weight and avoid a fall and Type 2 Diabetes?  Results of over hundreds of clinical trials conclude that regular progressive resistance training (PRT) is the answer.  This is the way the to retard skeletal muscle aging. Although this strategy has been in the scientific literature for near 30 years, surprisingly and sadly, very few adults follow an exercise program that includes resistance exercises (in the US population, an estimated 5% participate in resistance exercise versus more than 50% that engage in an aerobic regimen e.g. walking, swimming, jogging).  An additional piece of advice, stemming directly from clinical trial results, recommends the ingestion of 20-35 grams of quality protein post PRT workout to maximize the benefit gained from the resistance training alone. 

Progressive resistance training to retard skeletal muscle aging?

So what exactly is progressive resistance training (PRT)?  Simply, it is strength and speed training against a resistance which is either free weights e.g. dumbbells or barbells, weight machines (gravity resistance), calisthenics e.g. squats (body and gravity resistance) and/or use of resistance elastic bands or tubes.   In starting a program of PRT, consideration is given not only to the  type of resistance as just indicated but also, target muscles, frequency of exercise, intensity, and repetitions. 

Liu and Latham (2015)* reviewed 121 clinical trials with over 6,000 participants and concluded  that ” Doing PRT two to three times a week can improve physical function in older adults, including reducing physical disability, some functional limitations (i.e. balance, gait speed, timed walk, timed ‘up-and-go’, chair rise; and climbing stairs) and muscle weakness in older people.”  The average age in these studies ranged from 61 to 88 years.   Approximately half of the studies enrolled healthy sedentary older adults; the remainder were comprised of older adults with physical disabilities or limitations.   PRT lasted anywhere from 10 weeks to 2 years, targeting different muscle groups with increasing intensity.   It is noteworthy that older adults of any age, with or without physical limitations, will benefit from PRT.

A reasonable progressive resistance training program

What is an example of a successful PRT program?  A reasonable PRT program, based on results of interventional studies discussed above, has been developed for beginners, intermediate and advanced participants (Law et al., 2016)*.  The program is given below (PDF 1).  Target muscles are those of the chest, back, arms, shoulder, upper legs and lower legs.  For beginners, the program is 8 weeks in duration, twice weekly. Phase 1 (2 weeks) requires exercises at an intensity of 50-60% of one maximal repetition (RM) with performance of one exercise set with 12-15 repetitions.  For weeks 3-8,  the intensity increases to 60-69% of 1RM, the repetitions increase to 18, and a new exercise set is added. 

Ideally start with weight machines and trainer

Law et al., (2016) favors starting with weight machines and ideally a trainer to assure that the correct form is achieved for each exercise.  It is also advisable to discuss a new exercise program with your physician before setting forth.  The sample program for intermediate and advanced PRT modifies the beginner program and adds new exercises with increases in both intensity, sets and repetitions.  In lieu of weight machines, there are reliable established  free videos on strength training with dumbbells (PDF 2), and alternative exercises e.g. calisthenics and elastic bands (PDF 3)).  Remember the program must be progressive to be of benefit and hence must increase in intensity over time.

Progressive resistance training and protein supplementation are proven means to minimized age-associated sarcopenia and dynapenia.

To maximize the benefits of PRT, findings from numerous studies, albeit with a small number of volunteers, show that consumption of high quality protein e.g. soy or whey (20-35 gm) or essential amino acids leucine and isoleucine (3.5 gm) stimulates skeletal muscle formation and leads to better outcomes (mass, strength, performance) than PRT without protein supplementation.  Leucine and isoleucine cannot be synthesized by the body so both must be ingested. Leucine and isoleucine are the amino acids most adept at encouraging exercised muscles to up their production of major muscle proteins e.g. myosin.  Protein supplementation is based on studies with volunteers, 55-85 years of age, of various weights (normal to obese) who performed resistance exercises  (hand held weights and machines) for 10-26 weeks, 2-3 x per week, multiple target muscles with 3 sets of 8-12 repetitions at 70-85% maximal repetition.  

Do not forget protein supplementation

PRT plus protein supplementation is the anti-aging strategy that is definitely in sync with living a longer healthier life.  Consider the wealth of benefits from this strategy:  strength to perform all desired daily activities, avoidance of physical disabilities, maintenance of ideal weight or weight reduction, adequate handling of sugars/carbohydrates, avoidance of falls and an acceptable response to the cold.  These are advantages that guarantee continued independence and optimal quality of life.  These are benefits that should motivate every adult over 50 to participate in this strategy. 

Progressive resistance training is part of 4-prong exercise program for the older adult

PRT is one part of a 4-prong exercise program validated to minimize age changes.  PRT is of high priority considering the plethora of positive outcomes for the older adult.  However, the three other components (aerobics, balance and stretch ) of the 4-prong exercise program provide different but equally important advantages and will be discussed in my next blog.

Resistance exercise with machines

PDF 1 (Resistance exercises with machines) describes evidenced-based PRT proposed by Law et al., (2016)**   It consists primarily of exercises using machines one would find in a fitness gym or YMCA.  There are three progressive levels, beginner, intermediate and advanced that progress the individual from 1 set of 12 repetitions to 3 sets of 10 repetition over a period of 32 weeks.  Machine-dependent exercises is probably the easiest way to initiate PRT but this approach does require a gym membership.  The main advantage is that experienced personnel are available to assist with the use of each machine.  To provide a level of familiarization, PDF 1 also contains videos that demonstrate the proper execution of each exercise with the particular machine. 

Resistance exercises with dumbbells

PDF  2 (Resistance exercises with dumbbells) follows the progression of strength training defined by Law et al., in PDF 1 but substitutes dumbbells (hand held weights).   The advantage of these exercises is that they can be done at home.  However, one must purchase a set of dumbbells.  I have added videos for all of these exercises since it is essential that they be performed exactly as described to gain the most benefit and avoid injury.

Alternative workouts

PDF 3 (Alternative workouts) list 7 different workouts ranging in time and difficulty, available on line that one may also follow and that can be performed at home.  Although none per se have been subjected to a clinical trial they contain exercises providing benefits comparable to those defined in PDF 1 and 2.  The key point to remember is that resistance exercise needs to be progressive.  Thus either increase in weight or resistance and/or number of repetitions is required to yield strength benefit.

*  Liu C-J, Latham NK.  Progressive resistance strength training for improving physical function in older adults.  Cochran Database Syst Rev: July 8 (3): CD002759, 2009.

** Law TD, Clark LA, Clark BC.  Resistance exercise to prevent and manage sarcopenia and dynapenia. Annu Rev Gerntol Geriatr 36: 205-228, 2016.

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Insight 2: Skeletal muscles, aging and consequences

Exercise, Individual controls aging, , , ,

Gradual loss of skeletal muscle mass and skeletal muscle strength is the most insidious and perilous age change of all

In my first blog, I explained that the trajectory of the aging process depends largely on an individual’s lifestyle choices.  It is, therefore, important that every older adult understand exactly what age changes can be expected and secondly, and most importantly, how to negate or minimize them.  This blog will describe one of the most troubling and debilitating effects of aging, loss of skeletal muscle mass (also referred to as muscle size) and loss of skeletal muscle strength.  I will follow this up with insight 3 (my next blog) on what to do about these changes.  Specifically, I will detail successful strategies of progressive resistance training plus consumption of quality protein.

Muscle mass and strength decline over time

It is well established that muscle mass and strength gradually decline over time.  A starting point, although variable and depending on the daily level of physical activity, is generally denoted at about 50-60 years of age but may start many years earlier.  Loss of muscle mass, termed sarcopenia, is about 1%/year whereas loss of muscle strength, designated dynapenia, is much greater, at about 3%/year.  Unfortunately, these changes go unnoticed especially in the case of declining muscle size since fat accumulation sneaks in to replaces muscle cells that either shrink or disappear.  This is illustrated in the MRI scans shown below.  Often muscle weakness is regrettably accepted as an inevitable and unalterable age change.

Just a brief note on the terms, sarcopenia and dynapenia.  A diagnosis of either sarcopenia (loss of muscle mass) or dynapenia (loss of muscle strength) indicates that a measureable quantity of decline in muscle structure and function has been determined.  Although not set in stone, there are defined numerical “cut-off” values (e.g. values for mass of arms/legs, grip strength, force of knee extension, speed of walking or rising from a chair)  associated with each term that have been established by professional medical research groups worldwide.  If a patient undergoes an assessment in which mass and strength are quantified and the numerical values fall below the established cut-off, the physician will make a diagnosis of either sarcopenia or dynapenia or both and propose appropriate therapy to prevent a worsening of these losses.  However, the goal for the older adult should be to continuously optimize muscle size and strength so that a designation of sarcopenia/dynapenia is never obtained or even considered.

Consequences of loss of muscle strength (dynapenia) – abundant, negative, and life-shortenin

Why be concerned about loss of muscle strength?  Because this change definitely leads to:

(1) increased physical disability; decreased quality of life,

(2) increased risk of falling,

(3) shorter lifespan. 

The most destructive change induced by dynapenia is the most obvious:  reduced leg, chest, back, shoulder and arm strength/power (speed) that slow and hinder performance in all daily activities from standing to walking to lifting to breathing.  As mobility and gait speed decline so does the total level of physical activity, further accelerating the decline in strength and power.  This inevitably leads to physical disabilities, loss of independence, and reduced quality of life.  Secondly, diminished skeletal muscle strength alters posture, a change which causes unsteady balance and an elevated risk of a fall.  Falls are menacing events with a high probability of a fracture,  hospitalization and lengthy recovery.  Additionally, weakened chest, back and shoulder muscles secondarily compromise the ability to augment the exchange of oxygen and carbon dioxide during stressful activities e.g. climbing stairs.  A reduction in gas exchange generally slows or halts the activity and reduces independence.  Dynapenia not only translates into poor physical performance and physical disabilities but, sadly, it has been statistically associated with increased mortality (premature death).

Consequences of loss of muscle mass (sarcopenia)

Why be concerned about loss of muscle mass?  Because this change definitely leads to:  

(1) weight gain,  

(2) elevated risk for Type 2 Diabetes 

(3) cold intolerance.

Weight gain occurs because skeletal muscles burn up a lot of calories just for maintenance.  The totality of muscle mass is huge and exceeds that of all other tissues combined.  Less muscle tissue means less calories consumed by muscles and more calories converted to fat storage and hence an associated weight gain.  In addition to the increased poundage, accumulated fat in the older adult locates, for as yet poorly understood reasons, to sites (abdomen or waist area; on top of major organs such as the heart) that encourage chronic low level inflammation, a major factor contributing to tissue damage.  Clearly an unwanted effect.  Secondly, muscles are one of the prime tissue targets that readily acquire ingested sugars, a process facilitated by insulin.  Less muscle, less uptake of sugar by this tissue and more sugar remaining to circulate.  Persistently elevated sugar levels augment the risk for Type 2 Diabetes and furthermore, promote spontaneous oxidative damage (a type of tissue damage) throughout the body, another unwanted effect that accelerates aging.  Finally, an often overlooked function of skeletal muscles is heat production in the form of shivering at low ambient temperatures.  Less muscle mass means less vigorous shivering and reduction in expected warmth.  This is experienced as cold intolerance which means that at low ambient temperatures, one needs to put on more outerwear to keep warm.  This compensates for the loss of extra heat normally supplied by customary muscle mass of young adulthood.

Pictures depict loss of muscle mass 

The first illustrates the extent of muscle loss that typifies sarcopenia.  The second picture show actual data of  the cross-section of the thigh region obtained from MRI scans of 3 volunteers:  a 40 year old triathlete, a 74 year old sedentary man and a 70 year old triathete.  Triathlete are athletes who compete in the triathlon (competitive biking, running, swimming events).  In each cross-section of the thigh muscle, the small white center circle is the bone.  It is surrounded by dark material (muscle) and defined by an outer sheath.  Thigh scans of the 40 and 70 year old triathlete are remarkably similar.  However, major changes are observed with the center photo of a 74 year old sedentary man.  Muscle tissue has disappeared and the space formerly occupied by muscle cells has been replaced with adipose tissue, another name for fat.  This sobering image emphasizes the actual extent to which skeletal muscle can disappear.  Regrettably, as serious as muscle mass disappearance may appear, the associated reduction in strength is several fold greater than the observed loss of mass!

Significant loss of muscle mass

It seems reasonable to assume that if one understands the severe consequences of aging in skeletal muscle, then what must follow is both an interest and a motivation to avoid them with proven interventions.  My next blog (Insight 3) will discuss strategies that achieve this goal.

Aging Insight -Role of the life style choices in the aging process

Individual controls aging, , ,

Aging phase is radically different than all other life phases

This is the starting point for those interested in retarding age-related biological deterioration.

An incredibly important tenet of aging is the concept that the aging phase (generally late 50s onward) is radically different from all other life phases.  You may say you already know that because older adults are expected to experience a loss of fitness, a slowing down, a vulnerability to disease, and biological changes rarely evident in prior years.  Interestingly, most of these “inevitable” age changes are modifiable. Most importantly, the modification rests with the individual!

Life phases – their significance

Consider the life phases prior to aging:  conception to birth,  postnatal period through infancy, childhood, adolescence and adulthood (generally 20-50 years of age) . These are all life phases that are predominately (approximately 80% or more) dictated by genetic programs.  That is to say, that each of us did very little to progress within each phase or facilitate advancement from one phase to the next.  Consequently, we advanced through these phases with relative ease, thanks to our genes (DNA).  Environmental factors such as diet and exercise were also essential but  offered  a modest contribution compared to the genetic influence. 

Unlike these life phases, there are no genetic programs for aging.  Whereas several genes have been discovered with anti-aging or pro-aging attributes, researchers have not observed a full-blown genetic program that regulates the “aging” life phase of an adult older than 50 years.  Therefore, the hereditary contributions minimally to aging.  This conclusion rests on (1) theoretical data that indicates a genetic program for aging is biologically impossible (subject of another blog) and (2) studies of identical twins separated at birth and raised in different environments that show separated twins do not die at the same time as would be expected if there existed a genetic program for aging.  Additionally,  longevity studies with laboratory rodents inbred to possess virtually identical genes have revealed that lifespan is controlled by environmental – not genetic- influences.

Aging is an individual responsibility

In conclusion, of what value is this knowledge?  It is incredibly important because it says that (1) healthy longevity is largely the responsibility of the individual and (2) one can no longer blame the decrements associated with aging on parents and grandparents.  Basically, results of lifespan studies conclude that genes contribute about 20% to aging, whereas the environment, generally implied to mean life-style choices e.g. relating to exercise, diet, UV radiation, pollution exposure, sleep quality and quantity, stress etc, impact aging up the remaining whopping 80%.

In upcoming blogs, I will discuss the most meaningful ways to manage aging based on findings from clinical trials and scientific experimentation.  In  particular, I will start with perhaps the most serious age change. This is a gradual decline in muscle strength and actual muscle size.  These changes eventually lead to increased risk for diabetes, weight gain and most importantly, reduced mobility/balance and loss of independence. Proven interventions minimize these losses.