Tag Archives: disuse

Mobility, Exercise Physiology, Strength, Weight/Fat loss

Strength Training Alters The Trajectory Of Ageing

July 23, 2022 seanwilso 12 Comments

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On a global scale, the number of people over 60 yr is expected to more than double from 841 million in 2012 to more than 2 billion by 2050. This change in demographics will have profound implications for many aspects of life. Furthermore, Government bodies worldwide will be faced with considerable challenges related to aging policy and how best to deal with this new reality.

Of the many things that occur during the ageing process one of the most obvious signs is the loss of skeletal muscle mass (sarcopenia) and strength (dynapenia) with decrements in physical function and potential predisposition to disability. The process whereby there is a gradual loss of muscle mass and concomintant reduction in strength and physical function with ageing – is primarily caused by a loss in number of muscle fibres and preferential loss and atrophy of fast-twitch type-IIx fibres. The loss in fibre number and atrophy and loss of type-IIx fibres may be related to a loss of innervation of muscle fibres and a progressive loss of alpha-motorneurons (see here).

I want to try and explain, therefore, why I think it is so important for anyone over 40 to spend some time in their week lifting weights – or what is more technically known as resistance training (for the short version click here). There has been a significant amount of research conducted to show that one of the very best ways to slow down this process is to perform regular and challenging resistive-based exercise or weight training. Recently, more data has emerged suggesting that an even greater benefit may be achieved with high-velocity power training (see here & here). Such training is slightly different to traditional strength training in that exercises are performed with light-to-moderate loads or weight, but movement speed is performed at fast to very fast speeds. Evidence demonstrates that such activity can even reverse some of the changes seen due to the combination of ageing and sedentariness, by specifically stimulating and increasing the strength and size of these fast twitch type-II muscle fibres (see here).

Over 25 years ago a seminal and ground-breaking research study was conducted which completely questioned our scientific understanding of what was possible when very old frail people were exposed to resistance training. In many ways the findings of this study are at the core of why most, if not all people over 40, should be doing some resistance training – colloquially speaking – “pumping iron”. Whilst weight, strength or resistance training may not be everyone’s cup of tea if there is one form of exercise that can substantially and dramatically improve functional physical capacity it is this form of exercise that promises so much.

To show that middle-aged or older adults derive huge benefits from lifting weights and strength training — Lifting weights helps keep older people young

A pivotal moment in my life occurred whilst doing PhD studies in the early 1990s. My project was to review the literature in a chosen area and my area of interest that I had developed for a while by then was resistance training. I had been introduced to this type of exercise as a means to improve athletic performance as an aspiring junior Track & Field athlete. The dramatic improvement in my performance once I had added this to my training program was extraordinary. Since that point in time I have lifted weights regularly and done countless squats, deadlifts, power cleans, tossed tractor tyres, pulled on pulley’s, performed push-ups, stood on Swiss Balls, jumped over hurdles……………………………………

I chose to focus on and study the morphological (structural) and functional changes that occur in human skeletal muscle as we age and what can be done to attenuate or slow these changes down. The simple answer to that question is to perform regular but challenging resistance training.

It was during this literature review that a very important piece of research came to my attention.

The question that had remained largely unanswered was how much of the biological “age-related” decline in muscle size, strength and function is attributable to ageing per se or to the extremely sedentary lifestyles adopted by many people as they grow older?

It is quite clear that both the ageing process and disuse syndromes (meaning no physical activity) contribute to a preferential loss of muscle fibres, specifically type-IIx fibres, and it is these muscle fibres that are involved in movements that require high amounts of force, power and speed. The critical question is, then, to what degree could intervening with a progressive resistance training program alter the trajectory of this decline in muscle strength and function and is it indeed possible to even reverse some portion of the assumed “age-related” decline seen in older people.

The study that everyone should read

The study that was published in JAMA (The Journal of the American Medical Association) June 13, 1990 by Maria Fiatarone and colleagues (see here) undertook to determine the feasibility and the physiological consequences of high-resistance strength training in the frail elderly. You are probably wondering just how frail. Well, not wanting to mince my words these participants were very frail and were probably coming to the final years or even months of their lives.

Their average age was just over 90, there were 6 women and 4 men, 60% had level 2 pattern of care (meaning they were not independent and required moderate assistance), 8 had a history of falls, 7 habitually used ambulatory assistive devices, there was over 4 chronic diseases per person and daily medications taken per person equated to more than 4. The most common medical diagnoses were osteoarthritis (7 subjects), coronary artery disease (6 subjects), osteoporotic fracture (6 subjects) and hypertension (4 subjects). Four of 10 subjects had anthropometric evidence of undernutrition and a substantial proportion did not obtain the recommended daily allowance for important micronutrients. (Click on graphs for clearer view of results)

To show the difference in cross-sectional area of skeletal muscle in older adults that are independent compared to those that require assistance — Muscle mass versus functional mobility

Muscle accounted for only 31% of the total cross-sectional area of the thigh as determined by CT scans, which meant that there was more fat and bone than muscle and it would be stating the obvious to you that this is not conducive to good balance, strength or functional mobility. Baseline muscle function was terrible with a 6 metre walk taking an average time of 22 seconds to complete with one subject taking almost 1 minute. Many struggled to raise themselves out of a chair without the assistance of their arms. Strength at the beginning of the study was positively correlated with fat-free mass (total muscle) and midthigh muscle area, whereas it was related inversely to time taken to stand from a chair and time to walk 6 metres.

What this means is that those that had more muscle tissue and greater strength at the start of the study (baseline) were able to perform better on the walk test and chair stand by executing these tasks more quickly.

Reduced physical strength and mobility with ageing affects health and wellbeing — The ageing process can be modified with exercise

Now to the interesting part of the study.

The results

Notwithstanding that there were only 10 elderly people involved, the findings were incredible and well beyond what was expected. What was even more surprising was only one simple exercise was employed: unilateral leg extension (i.e. single-leg) using a standard weight-and-pulley system. The 8-week training program used principles of progressive resistance training (in other words, as they got stronger the relative loads were increased), employed concentric and eccentric muscle contractions (whereby the muscle shortens and lengthens whilst under tension), trained 3 times/week completing 3 sets of 8 repetitions of each leg in 6-9 seconds/rep, with 1- to 2- minute rest periods between sets.

In light of their age, their general health status and the fact that they were only doing one simple exercise that primarily focused on the quadricep muscle (thigh) it would be within reason to think that the outcomes of the program would be quite negligible. However, that did not happen and this basically demonstrates that no matter how old, how injured, how dysfunctional you may be, your body and the skeletal muscle you stimulate – by performing challenging physical movement – will not only respond but it will respond quite robustly.

Exercise slows the ageing process and how weight training can increase muscle strength even the those that are 60, 70, 80 years old — Muscle strength improvement follows resistance training

Tolerance of the resistance training program was excellent with 90% completion rate (9 out of 10 finished), and no cardiovascular complications were seen. There was occasional hip and knee discomfort and that would be expected but no analgesics were required and no training sessions were missed. Gains in muscle strength were impressive and after just 8 weeks of training average strength had increased by over 170% and responsiveness to training was not different in men vs women. Some subjects made quite extraordinary gains of almost 400%. Muscle size increased in 5 of the 7 of the subjects that were CT scanned for total midthigh muscle area. Of those with stable body weight, the mean muscle area increases were significant with total midthigh muscle area going up 11.7%, the quadriceps up by 14.5% and the hamstrings/adductors by 10.6%.

Functional mobility accompanied the improvements in strength and muscle hypertrophy (growth). The time taken to complete the walking test improved substantially from 44 seconds to 29 seconds representing a 48% improvement. Two subjects no longer needed canes to walk at the end of the study and one of three subjects who could not initially rise from a chair without the use of their arms became able to do so. Importantly, no subjects experienced falls during the study. The physiological and functional improvements were truly incredible. The effects of detraining were assessed too (stopped the program) and what this showed was that the gains made were very quickly lost with a significant 32% decrease in maximum strength after only 4 weeks of ceasing the training.

What are the major implications of these findings?

exercise physiology, exercise physiologist, Townsville Queensland Australia — Strength is fundamental to life

The results clearly demonstrated that progressive resistance training at sufficient loads (greater than 80% 1RM; i.e. lifting 80% of the maximum weight you can lift once) can induce dramatic and substantial increases in muscle strength, size and function in frail men and women up to 96 years of age. Achieving such favourable responses to strength training in these subjects is remarkable when one considers their very advanced age, extremely sedentary lifestyles, multiple chronic diseases and functional disabilities, and nutritional inadequacies. What is clear is that the preservation of fat-free mass (muscle) as one ages is a critical factor and directly affects muscle strength in the older person.

Exercise and resistance training specifically, is able to provide the neuromuscular system the appropriate physiological stimulus to reverse and modify a portion of the muscle weakness and functional loss often and simply put down to old age. Re-read that sentence because that is huge!

The final thing I would like to say on this study which deserves comment is that the results are all the more impressive because the subjects performed only one simple exercise (leg extension done unilaterally). Obviously if one employs resistance training exercises that are more complex, multi-jointed and aim to stimulate all the muscles of the upper and lower extremities (using different exercises) the structural and functional improvements would potentially be even greater.

For local Townsville residents interested in FitGreyStrong’s Exercise Physiology services or exercise programs designed to improve muscular strength, physical function (how you move around during the day) and quality of life or programs to enhance athletic performance, contact FitGreyStrong@outlook.com or phone 0499 846 955 for a confidential discussion.

For other Australian residents or oversees readers interested in our services, please see here.

Disclaimer: All contents of the FitGreyStrong website/blog are provided for information and education purposes only. Those interested in making changes to their exercise, lifestyle, dietary, supplement or medication regimens should consult a relevantly qualified and competent health care professional. Those who decide to apply or implement any of the information, advice, and/or recommendations on this website do so knowingly and at their own risk. The owner and any contributors to this site accept no responsibility or liability whatsoever for any harm caused, real or imagined, from the use or distribution of information found at FitGreyStrong. Please leave this site immediately if you, the reader, find any of these conditions not acceptable.

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Strength, Nutrition

Does Soy Protein Really Inhibit Resistance Training-Induced Strength Gains In Older Adults? Part 2

January 14, 2020 seanwilso Leave a comment

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Where Good Research Leads To Poor Interpretation

In my last research article review titled “Muscle strength gains during resistance exercise training are attenuated with soy compared with dairy or usual protein intake in older adults – part 1” (see here), no additional benefit for improvements in strength, body composition, physical function, or quality of life when additional protein from either dairy or soy versus usual protein intake were seen after 12 weeks of progressive resistance training exercise in healthy older adults.

The focus of this article – part 2 of this review – is to discuss the findings that suggest that increased soy protein intake attenuated improvements in muscular strength compared to dairy protein and usual protein. I want to explore some of the results of this study that are discordant with the conclusions reached by the authors. Their take-home message I believe is therefore misleading and misrepresents what the study actually showed.

The biggest problem with this is that the vast majority of media (print, TV, social media etc), websites, blogs and other avenues used to report on this study, haven’t taken the time to analyse or assess whether or not the conclusions reached are valid. In fact, when I Googled the net for websites, pages or blogs that wrote about, and reported the results of the study in question, I could not find ONE that had even questioned or scrutinised the conclusion against the actual results produced.

This highlights a bigger issue regarding the veracity of health, exercise, fitness and nutrition news that is reported and shared – following publication – in the blink of an eye. Whilst I do not want to explore this further today, it is certainly something that bothers me and something I would like to write about soon.

Let’s look at some of the issues with the conclusions reached by the authors of this paper.

Problem #1 – One of the main findings claimed to have been shown by this research was that:

Increased soy protein intake attenuated gains in muscle strength during resistance training in older adults compared with increased intake of dairy protein or usual protein intake” (pg. 27).

Now unless you read the whole study and scrutinised the results there would be no way of knowing if this conclusion is well-founded or not; so let’s have a look at the results table to see if this is a fair assessment of their data (click on table to expand).

Strength gain with Soy protein versus Dairy protein in older adults — Strength improvement results for each diet intervention

The first thing you’ll notice is that the only exercise that soy protein attenuated gains in muscle strength was leg press 8RM (RM; maximum weight lifted for eight repetitions); for all other exercises no differences were found for protein source and subsequent strength improvement. More specifically, there were no significant differences between the soy, diary and usual protein group for strength improvement in isometric knee extensor strength, handgrip strength, chest press, knee extension, lat pulldown and leg curl. Thus, strength training adaptation from resistance training in older adults for all exercises, bar one (leg press), was the same irrespective of the protein source provided. The significant difference found therefore for the sum total 8RM lifted for all 8RM exercises was most likely due to the difference in leg press 8RM. (Note: percentage improvement in lat pulldown 8RM was greater in usual protein vs dairy but with no difference vs soy; this doesn’t, however, detract from the core proposal above).

Strength increases through Leg press — Leg Press for increasing lower body muscle strength

If that is the case, the question that needs to be asked is, why was this ignored and not explored in the discussion? There are certainly some intriguing possibilities regarding this result. Does soy protein, for example, possibly attenutate gains in lower body but not upper body strength? Is there any other explanation for the attenuated strength for Leg press and, if so, would that mean that there are essentially no differences between the source of the protein and the strength improvement? I’m not sure what mechanism of action you would propose to explain a differential for strength gain between lower and upper body when consuming soy versus dairy protein? The authors do hypothesise that the inhibition of strength gain due to soy protein could have been hormonally based by stating:

Instead, it is more likely that the attenuation of the strength increase in the HP-S group was due to some effect of the soy inhibiting the increase in strength. Soy foods not only contain soy protein, but also contain isoflavones, which exhibit estrogenic properties [Barnes 2012]. A recent study demonstrated that 14 days of soy protein supplementation in resistance trained young men during training reduced serum testosterone concentrations in the first 30 min post-exercise compared with whey protein or a carbohydrate control [Kraemer et al. 2013]. It was proposed that this blunted serum testosterone response might reduce the anabolic response in skeletal muscle, thus attenuating the accretion of contractile protein and muscle strength gains. This may explain the attenuated increase in strength gains observed in the HP-S group in the present study (pg. 32).

However, I don’t think that the abovementioned soy-induced reduction in serum testosterone has been shown to affect muscle contractile properties in an appendicular specific manner (i.e. lower body responds differently to upper body). Moreover, in contrast to the authors proposition above, post-exercise testosterone response does not appear to correlate with, nor is it in any way indicative of subsequent strength gains following resistance training as shown, for example, by the work of Morton and colleagues (2016).

Problem #2: Assessing the results listed in table 2 for Leg Press highlights another interesting difference between the soy and dairy protein groups. The baseline strength values for the dairy and usual protein groups are significantly lower than the soy protein group (55.0 vs 77.3 vs 56.6). In fact, the 8RM baseline strength value for the soy protein group is approximately 40% higher than the other protein groups. Such a large difference would have been unexpected following randomisation with most other baseline values relatively comparable. How this difference affected the statistical analysis is difficult to say but I would have liked the authors to discuss this to put such a baseline disparity into perspective.

Given what was discussed in problem number 1, a separate statistical analysis should have been conducted on all 8RM exercises with leg press 8RM excluded. This assessment would have been able to tease out if the attenuated strength gain seen in the leg press also applied to the 4 other exercises. Based on the data for each individual exercise (excluding leg press), no differences were observed; however, there may have been insufficient power to detect any real differences. By grouping these 8RM exercises together this question could have been answered. As it stands, soy-induced strength gain attenuation can only be claimed for the 8RM leg press.

gym training for strength gain — Are functional strength gains limited by machine-based training?

In relation to the training sessions, what is not particularly clear is whether the participants trained one-on-one with their instructor in solitude or whether the sessions involved small groups. It is feasible that if participants trained individually and at the same time but with different instructors, or in small mixed groups, those allocated to the dairy and usual protein experimental diets may have inadvertently or surreptitiously observed what the ‘stronger’ leg press soy participants were lifting and been incentivised to ‘push’ that bit harder in an attempt to bridge the gap.

Final comments: Based on the results of this study, I would have worded the conclusion very differently to that which was put to print by the Thomson et al. Something like the following would have probably been more apt:

Increased soy protein intake appeared to attenuate gains in leg press muscle strength only, compared with increased dairy protein or usual protein intake. With all other exercises there were no notable differences. Further research is required to explore the possibility that soy protein may specifically inhibit lower body strength gains from resistance training in older adults.

Post-script: Following further analysis and publication of part 2 of this blog, I wrote a letter to the Editor of Clinical Nutrition Journal outlining, what I believed, were some of the flaws regarding the interpretation of the results of this trial. Upon peer review this was accepted for publication and can be found here. If you are unable to access this correspondence and the authors reply to my letter, please contact me and I should be able to assist.

References

Barnes S. (2004) Soy isoflavones-phytoestrogens and what else? J Nutr 134:1225S-8S.

Cermak et al. (2012) Protein supplementaiton augments the adaptrive response of skeletal muscle to resistance-type exercise training: a meta-analysis Am J Clin Nutr 96: 1454- 64.

KraemerWJ et al. (2013) The effects of soy and whey protein supplementation on acute hormonal reponses to resistance exercise in men. J Am Coll Nutr 32:66-74.

Morton RW, Oikawa SY, Wavell CG, Mazara N, McGlory C, Quadrilatero J, et al. Neither load nor systemic hormones determine resistance training-mediated hypertrophy or strength gains in resistance-trained young men. J Appl Physiol July 1, 2016;121:129-138.

Thomson et al. (2016) Muscle strength gains during resistance exercise training are attenuated with soy compared with dairy or usual protein intake in older adults: A randomized controlled trial. Clinical Nutrition. 35: 27-33

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Exercise Physiology, Strength, Mobility

Resistance Training Alters The Trajectory Of Ageing

December 10, 2018 seanwilso Leave a comment

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Recently I published an article on my website titled:

“Strength training can alter the trajectory of ageing”.

After receiving feedback from some of those who regularly visit my website and social media channels, there were some suggestions to provide a summarised or bottom-line version of some of my articles for those that are looking for something that gets straight to the point. So here it is. The short version of the abovementioned article.

The research paper that everyone should read

The year was 1990 and researchers Maria Fiatarone and colleagues published their findings in The Journal of the American Medical Association after undertaking a study to determine the feasibility and the physiological consequences of high-resistance strength training in the frail elderly. These participants were very frail, had an average age over 90, suffered many co-morbidities and were basically not in very good condition. Their muscles were very atrophied, functional capacity was very poor and their physical movements were very slow.

After 8 weeks of progressive resistance training that only utilised one exercise that focused exclusively on the quadricep (thigh) muscles, the results were totally unexpected. Gains in muscle strength were impressive averaging over 170%, with some subjects making extraordinary gains of almost 400%. There was an accompanying increase is muscle size of over 10% as assessed by CT scans. Functional mobility accompanied the improvements in strength and muscle hypertrophy (growth). The time taken to complete the walking test improved substantially from 44 seconds to 29 seconds representing a 48% improvement. Two subjects no longer needed canes to walk at the end of the study and one of three subjects who could not initially rise from a chair without the use of their arms became able to do so. These physiological and functional changes were truly incredible.

What is clear is that the preservation of fat-free mass (muscle) as one ages is a critical factor and directly affects muscle strength in the older person.

Exercise and resistance training specifically, is able to provide the neuromuscular system the appropriate physiological stimulus to reverse and modify a portion of the muscle weakness often and simply put down to old age.

Re-read that sentence because this is huge! So off you go and start lifting.

For the longer version please see here.

Disclaimer: All contents of the FitGreyStrong website/blog are provided for information and education purposes only. Those interested in making changes to their exercise, lifestyle, dietary, supplement or medication regimens should consult a relevantly qualified and competent health care professional. Those who decide to apply or implement any of the information, advice, and/or recommendations on this website do so knowingly and at their own risk. The owner and any contributors to this site accept no responsibility or liability whatsoever for any harm caused, real or imagined, from the use or distribution of information found at FitGreyStrong. Please leave this site immediately if you, the reader, find any of these conditions not acceptable.

© FitGreyStrong

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Exercise Physiology, Strength

Can Older Adults ‘Think’ Themselves Stronger?

May 17, 2018 seanwilso Leave a comment

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Research conducted recently and published in the journal Medicine showed that something amazing happens when you put intense mental effort into thinking or imaging you are lifting or moving with maximal exertion. Muscular strength can increase substantially and can match gains in strength made through more traditional intensive resistance training. What researchers discovered was that:

“strength of elbow flexor muscles, a frequently used large upper extremity muscle group during daily living, can be significantly improved by training of high motor effort combined with low-intensity muscle contraction in older adults, and the strength increase accompanied central signal augmentation that suggests an enhancement of descending command that was thought to have improved motor unit recruitment and activation leading to greater force production without changes in muscle morphology.”

Simple put, the strength of the elbow flexors – or colloquially known as “your guns” – were substantially increased in older adults after flexing the right elbow joint at minimal force whilst simultaneously mentally urging the forearm to pull upwards maximally. This type of ‘exercise’ is known as motor effort training or MET.

Motor effort training with low exercise intensity improves muscle strength and descending command in aging — Title Page

Trial summary: Training involved contracting the arm flexors at 30% of maximal effort while at the same time mentally urging the forearm to pull upward (elbow flexion) maximally for 5 seconds followed by 5 second of rest; this was repeated 25 times. Following a 2 minute rest this was repeated again. Training lasted for 12 weeks with 5 training session per week. This training protocol was compared to traditional strength training where participants performed 50 trials of isometric right elbow flexion at 80% of maximum force for 5 seconds in each training session; 60 session were completed. Training sessions, trials and trial duration were the same between groups. The intensity of the traditional strength training group was adjusted every 2 weeks based on subjects’ newer maximum strength attained as participants adapted to the training.

The current study is the first to show MET-induced strength gains in older adults with the improvements achieved statistically non-significant to traditional strength training. Strength improvements attained via MET appear to be modulated by an enhanced capacity to generate neurological drive from the motor cortex that then increases recruitment of motor units. What is particularly attractive about MET for older weak or frail adults is that it reduces problems and the risk of injury associated with performing conventional high-intensity strength training.

The authors conclude:

“The finding that the difference in strength increases between the MET and CST (traditional strength training) groups was statistically insignificant argues that training of motor imagery combined with low-intensity muscle exercise is a safe and effective method for muscle strengthening for vulnerable populations such as frail older individuals.”

Large increases in motor activity-related cortical potential

For local Townsville residents interested in FitGreyStrong’s Exercise Physiology services or exercise programs designed to improve health, physical function and quality of life or to enhance athletic performance, contact FitGreyStrong@outlook.com or phone 0499 846 955 for a confidential discussion.

For other Australian residents or oversees readers interested in our services, please see here.

Disclaimer: All contents of the FitGreyStrong website/blog are provided for information and education purposes only. Those interested in making changes to their exercise, lifestyle, dietary, supplement or medication regimens should consult a relevantly qualified and competent health care professional. Those who decide to apply or implement any of the information, advice, and/or recommendations on this website do so knowingly and at their own risk. The owner and any contributors to this site accept no responsibility or liability whatsoever for any harm caused, real or imagined, from the use or distribution of information found at FitGreyStrong. Please leave this site immediately if you, the reader, find any of these conditions not acceptable.

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