NY Times Incorrectly States Exercise Doesn’t Make Bones Strong

Earlier this month media misrepresentation of science appeared on the New York Times website. On April 1st, 2016 Gina Kolata wrote an article for their Health section entitled: “Exercise is Not the Path to strong Bones.” You can read the full article HERE, but I will break it down in this post. I should note that the article was posted on April Fool’s Day. I originally saw this and thought the article was a joke, but unfortunately it was not. As this article covers an area where I have substantial expertise, I had to give a critique. Excerpts from the article and my responses are as follows:

“Misconception: All you have to do is walk or do modest strength training exercises to build strong bones. Actually: Exercise has little or no effect on bone strength.”

This begins the article and really encapsulates the problem; it’s not precise enough. It claims walking isn’t enough to build strong bones (research does generally support this). It also claims that modest strength training doesn’t build strong bones (this is not necessarily true – modest needs to be defined and the individual’s training history must be accounted for). It then claims that exercise has little or no effect on bone strength (exercise is too vague; what type of exercise are we talking about?).

“…scientists did rigorous studies, asking if weight bearing exercise increased bone density in adults. They used DEXA machines, which measure bone density by hitting bones with X-rays. Those studies failed to find anything more than a minuscule exercise effect — on the order of 1 percent or less, which is too small to be clinically significant.”

First of all DEXA (bone density) has limitations. It’s a 2-dimensional surrogate for a 3-dimensional structure, the size, shape and composition of which all can influence bone strength. As the author notes, there are studies that show no change in bone density with exercise, but the author fails to mention that many studies do show that strong bones are associated with increased bone density (and vice versa). For example, Almstead et. al, 2011 show 2-7% increases in BMD after strength training. But the bigger oversight here is that very small (even 1%) increases in bone mass can in fact have a huge impact on strength. It depends on where the bone is added. If it’s added on the outer surface of your leg bone (femur) for example, the strength will go up because you’ve increased its polar moment of inertia.

“More recently, using new and very expensive machines that scan bone and are able to show its structure at a microscopic scale, they reported a tiny exercise effect in one part of the bone’s architecture known as the trabecula, little branches inside bone that link to each other. The cortical shell — the outer layer of bone — also seems to be slightly thicker with weight bearing exercise. But these are minute changes, noted Dr. Clifford Rosen, a bone researcher at the Maine Medical Research Institute. There is no evidence that they make bone stronger or protect it from osteoporosis, he said.”

First, these machines aren’t that new. Second, this line stunned me as I know Dr. Rosen. We have authored papers together. I emailed Dr. Rosen to ask if he actually said this and his response was, “A little out of context!!! The whole article was a bit out of it. Of course I never saw it before pub[lication].” This was as I expected, but it highlights another big problem. Even when the proper experts are interviewed, the message often gets garbled and they aren’t given a chance to proofread the message before it goes to the public.

“At this point nothing except injections of parathyroid hormone and, perhaps, a new injectable drug called abaloparatide now being tested in clinical trials, make bone denser and stronger.”

This is a completely unsupported claim. Again, we know that size, shape, and composition (quality) of bone all play a role in determining a bone’s strength. We know this from a combination of human and animals studies (check out my work in 2008 and the work of my mentor Karl Jepsen in 2013 as examples). The two literature groups, of which these two articles are a part, have to be examined together. And the message is clear, anything that imparts even small changes to the size, shape, or composition of bone can have an effect on its strength. The relationships are complicated, and still not fully understood, but they are real. Exercise in the form of weight training, is one very accessible means for humans to impart positive changes to their bone size and strength.

I emailed Gina Kolata after reading her article requesting that she take it down because, as written, it was too misleading to the public. In fact, beyond misleading I said it was dangerous as it undermines decades of research which support the effectiveness of weight training in keeping bones strong and preventing fractures. To date Gina has not responded to my email and the article remains live on the NY Times website.

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My Picks for Best Free Weight Exercises

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I was one of 20 fitness experts asked by Predator Nutrition to give their favorite free weight exercises for upper body, lower body and core strength. Check out the full article to see what I chose!

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Programming for CrossFit (2016 Update)

IMG_3820 An updated version of last year’s “How I Program For CrossFit” article recently went live on the Solace New York blog. The article is Part 1 of a three part series I am writing on how programming at Solace can be tailored for different individuals to reach their fitness goals. To read the full article CLICK HERE.
 
 

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CrossFit Training May Enhance Brain Function

In many individuals the aging process coincides with a decline in brain function. The degree of decline can be mild or severe (i.e, Alzheimer’s). Therefore, finding ways to improve or maintain brain function is of great importance. In a recent article by Murawska-Cialowicz and others (2015), scientists examined the effect of CrossFit training on the production of brain-derived neurotrophic factor (BDNF). This hormone promotes nerve formation and survival and is responsible for short-term memory. It also plays a role in cognition, memory, and learning.

The Takehome: In this study CrossFit training was found to lower body fat percentage and increase maximum oxygen uptake in women. In men, CrossFit training increased time to exhaustion during an aerobic endurance test and in both men and women CrossFit training increased lean body mass, and resting BDNF levels. The body composition, oxygen uptake and time to exhaustion findings have been observed in other studies, but the BDNF findings are novel. The findings suggest that CrossFit increases hormone levels that help promote and maintain brain function. Although a direct link has not been made in this study, a mechanism by which CrossFit training can keep your memory sharp and prevent memory loss in aging has been proposed.

STUDY DETAILS:
Experimental Design:

  • The study examined 7 men (~26 years old) and 5 women (~24 years old)
  • CrossFit training was conducted for 3 months with 60 minute sessions 2x per week. Sessions generally had two parts: A skill or strength segment followed by a workout of the day (WOD) that had an aerobic emphasis.
  • Participants performed two tests twice before and after training: a Wingate test and a week-later progressive test (both performed on a cycle ergometer). The Wingate assessed aerobic capacity. The progressive test measured VO2max (maximal oxygen uptake) and carbon dioxide output.
  • BDNF and Irisin (a small protein fragment that regulate blood sugar levels) were measured by blood serum analysis.
  • Height, body mass, body composition, and body size measurements were also taken for each participant before and after the experiment.

Results:

  • After 3 months of CrossFit training, women’s waistlines and body fat percentage both decreased. Aerobic capacity (VO2max) also increased significantly (average increase ~14%).
  • In men, time to exhaustion (progressive test) increased significantly after CrossFit training.
  • In both men and women, lean body mass increased significantly.
  • Resting levels of BDNF increased (progressive and wingate tests) after CrossFit training (levels were consistently greater in men than women before and after the study).
  • Irisin levels decreased in women after CrossFit training and were statistically indistinguishable from before-training levels in men.

Limitations:

  • The WODs were indicated as all having an aerobic emphasis. This may have just been a phrasing issue, but at face value this would not be a typical CrossFit WOD as CrossFit uses high intensity training to simultaneously enhance aerobic and anaerobic fitness – the focus is rarely just on aerobic capacity.
  • The sample size in this study is quite low and was likely a factor in many test parameters only being statistically different for one sex.
  • The authors’ stated correlation between Irisin levels and BMI, % Fat and VO2max is unclear. The correlation may have been made from pooling women and men together or it may have been done separately. The data appears only as a line in the text, so it is hard to tell for sure.
  • Nearly all Wingate test parameters were insignificant when comparing parameters before and after training. Why choose to use a test that is so ineffective? If the authors didn’t know it would be so ineffective, what are the implications of this finding? These ideas deserved more discussion.
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Muscle Gain in the Elderly – How Long Does It Take?

For someone like myself, it’s very obvious that strength training can improve musculoskeletal health in individuals of all ages – even the elderly. However, I still encounter many older individuals who believe it’s too late to gain muscle mass, or that it will take too long to build muscle mass since they are are no longer young. Any seasoned strength coach who has trained an older individual knows this isn’t the case. But how long exactly does it take for older individuals to gain muscle mass while strength training? A recent study, Lixandrao et al., 2015, asked this question for men and women over 50 years of age.

The Takehome: This study indicated that strength training of the legs in the elderly can increase muscle mass after 9 weeks and increase leg strength after 10 weeks. The time-frame here is quite short. In a little over two months both size and strength were gained, and the training required was very basic (leg press machine using 4 sets of 10 repetitions twice a week). So, if you are an older individual or know someone who is, encourage them to start training – there is no such thing as “too old.”

STUDY DETAILS:
Experimental Design:

  • 14 participants (8 men and 6 women) who were not physically active over the past 6 months.
  • Men and women were randomly assigned into a Resistance Training group and a Control Group (mean age of 60 and 65 years old, respectively).
  • Vastus lateralis (quadriceps) muscle cross-sectional area (by MRI) and leg press 1 repetition maximums (1RMs) were measured at the beginning and end of the study.
  • Leg press resistance training was conducted twice a week for 10 weeks (20 minute training sessions): 4 sets of 10 repetitions. Resistance was set at 70% of 1RM for the first 5 weeks and 80% for the final 5 weeks.

Results:

  • After 10 weeks only the resistance trained group showed increases in their 1RM value and vastus lateralis cross-sectional area.
  • Vastus lateralis muscle cross-sectional area was significantly increased after both 9 and 10 weeks of training.

Limitations:

  • As is common in these types of studies, the number of participants in the study was small.
  • Men and women were not examined separately and the individual results for each group might be different.
  • Only leg muscle growth was examined in the study and the time course for muscle growth in other muscles may be different.
  • The training protocol only used two levels of resistance (70% and 80% of 1RM). The results may not apply to other resistance levels or repetition schemes.
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Scientists & Doctors Have a Responsibility

For someone who has obtained an advanced degree, the paper on the wall generally indicates a great deal of time and effort spent studying a certain discipline. As such, the individual holding the degree is generally considered an expert or authority in their chosen field. Law, medicine, and science are just some of the disciplines that offer advanced degrees. There is a tendency for society to be very impressed with advanced degrees and high-level credentials. In one way, an advanced degree gives some assurance that the person knows what they are talking about, but it cuts both ways; a degree is no guarantee and at worst an advanced degree can can be used as a tool to put others down. I recently had an email interaction that illustrates this situation. Note, I’ve censored the personal points below because my goal here is to not single individuals out, but to discuss behavior that I feel is detrimental to society as a whole.

I recently signed up for some customized remote programming. The customization was based on several tests that had to be performed in the beginning of the program. I was surprised that one of the tests was expecting a very high level of strength in order to be given their more advanced programming. The standard was set so high, in my opinion, that it made me question what the goal of the program was. I asked the individuals running the program to clarify and they maintained their upper body strength requirement (which I did not meet), is something that should be readily obtainable for a male. I asked them where they got their criteria from and they said that it’s readily evident from the many individuals they have trained or crossed paths with. Now, I know a thing or two about strength training and I have crossed paths with a lot of individuals as well, and my observations didn’t suggest such a tough strength criteria at all. They further elaborated that there were scientific studies that lead them to settle on their upper body strength requirement. I asked them to send me a list of the studies and the individual I was talking to didn’t have this list. He said he would have to ask his colleague.

A week or so later I still had not received any data, so I touched base again. The response I got was as follows:

“Hayden I forgot to send you the info on the data. It’s a meta analysis of research that we apply…”

So, at this point I was expecting them to send me a single meta analysis study. These types of studies systematically compile data from many other studies and run a statistical analysis on the pooled data to arrive and a conclusion. But the individual continued as follows:

“…Google scholar search for ‘strength and conditioning journal strength balance’ will give you most of the articles used. from there follow those articles for applicable cited sources…”

So, I asked for a list of references that had the relevant data and was told to perform a Google search. That search returned about 243,000 items. I then imagined myself at a scientific conference (I have presented at many) where a member of the audience asked me what I based my theory on, and I told them to perform a Google search. I would have gotten thrown out of the conference. That’s not how science works. I will also add that the very first reference in the list from the Google search has nothing to do with upper body strength – it is clearly not relevant to the question I was raising. This is a huge red flag against credibility. The response continued as follows:

“Regarding explaining the methodology of all of it to you, with a lot of respect the best answer I can give is that there is a reason we only hire staff with a doctorate or athletic training degree. The lengths to which we have extrapolated data goes above what is easily explained…I think the best option for you (since you live locally) would be to come out and go through a live exam if that’s in the realm of possibility for you.”

As if the initial part wasn’t disappointing enough, the individual has now proceeded to tell me that I wouldn’t understand the reasoning because a doctorate is needed. The individual writing possessed a Doctor of Chiropractic (DC) and apparently didn’t realize that I too had a doctorate…and a masters…and a bachelors (all in hard medical sciences). But it really shouldn’t have mattered. Doctors should be able to explain their reasoning. Offering a live exam was even more strange. Apparently if I pay more money everything will become clear? I told them I did have a doctorate and would in fact understand their reasoning. The response was:

“I provided you with a means to find your answer. All I’d be able to say beyond that is ‘this is what we read, this is how we interpreted, this is how we apply’. It’s obvious that you’re intelligent and inquisitive, I like people like that in our circle. I also think is only makes you more qualified to understand that a simple answer to your complex question just isn’t realistic.”

Again, Imagine if I gave that response at a scientific conference. I would be shunned. From the above exchange there is no way to know if there is any substance to the programming I bought into. The creators based the program’s integrity on science and refused to provide references to those studies. Their advanced degrees were used as an excuse to remain aloof. Yes, science can be very complicated, but in these medical and health related disciplines the purpose of science is to help humanity – all of it, not just those with advanced degrees. One of the benefits of obtaining a PhD in my chosen field is that you are taught to communicate your ideals simply and succinctly. Every grant submitted to the NIH (National Institutes of Health) for funding must have a paragraph explaining the project in simple language. Regardless of the topic it can be done and it’s important that it be done. The Alan Alda Center for Communicating Science says it beautifully in their mission statement:

“We believe that scientists have a responsibility to share the meaning and implications of their work, and that an engaged public encourages sound public decision-making.”

So, the next time you cross paths with someone holding an advanced degree, remember, if their theories are based on personal observation, they should say so. If their theories are based on studies, they should point to them. Scientists and doctors should be responsible, and information should be shared. If they don’t know how to make their ideas clear, they should learn how, and if they refuse to do so, they should expect you to call them on their refusal. The betterment of humankind depends on it.

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High Intensity Training and Free Radical Damage

From Wikipedia

High intensity training (exercise) has become increasingly popular over the past decade. Those who conduct this type of training see excellent results in terms of body composition and cardiovascular fitness. Several recent scientific studies have confirmed these observations; High intensity training is equally or more effective than other types of training, and gives these results with notably shorter training times. However, the mechanism by which a few minutes of high intensity training affects these changes remains unclear. In a recent study (Place et al., 2015), scientists asked if single bouts of high intensity exercise affect change through increasing reactive oxygen species (free radicals) in muscle tissue, and if these effects are less prevalent in those individuals who are highly trained endurance athletes.

The Takehome: Reactive oxygen species (free radicals) are commonly associated with a variety of negative health effects, but they may be the mechanism by which high intensity exercise works. Recreationally active men who were exposed to a single session of 3-6 sets of 30 second high intensity cycling had high levels of free radicals and marked fragmentation in their muscle sarcoplasmic reticulum (the part of the muscle cell that regulates calcium release), but those who were highly trained endurance athletes had neither. Specifically, the ryanodine receptor 1 calcium channels were fragmented in recreationally active men, but not in endurance trained men whose receptors were intact and whose muscle cells possessed high levels of antioxidants. Thus, free radical damage may be the mechanism by which high intensity training works and endurance-trained athletes may be unable to reap the same benefits as those who aren’t.

Fragmentation of ryanodine receptor 1 calcium channel in mice was associated with substantial calcium leakage. Since calcium leakage from the sarcoplasmic reticulum is known to boost production of mitochondria (the parts of cells that produce energy and prevent fatigue), the authors propose that high intensity interval training improves cardiovascular fitness through the following series of events (note they don’t directly test all of these points – see below for details): high intensity training produces reactive oxygen species (free radicals), reactive oxygen species degrade specific calcium channels in the muscle sarcoplasmic reticulum, calcium then leaks out of the sarcoplasmic reticulum and into the rest of the muscle cell. The increase calcium levels in the muscle cell cause it to make more mitochondria which provides that cell with a greater capacity to produce energy, and thus greater capacity to complete work. This series of events appears to be ineffective in people who have substantial endurance training. So, if you want the benefits of high intensity training, it seems that free radical damage may be necessary and that a high volume of endurance training may result in sub-optimal results.

STUDY DETAILS
Note: This study is very dense and there are more experiments and details than can be summarized here, so I have highlighted only select portions below.

Experimental Design:

  • Recreationally active men and endurance-trained men (marathon runners) performed 3 sets of high intensity (all-out) cycling for 30 seconds each. 4 minutes of rest were given between sets.
  • Biopsies of the vastus lateralis (quadricep) muscle were taken after the high intensity cycling to assess the integrity of calcium channels in the muscle sarcoplasmic reticulum.
  • Force production was measured using direct stimulation of isolated vastus lateralis fibers taken from biopsies before and after cycling.
  • Molecular expression analyses were conducted using PCR and immunohistochemistry.
  • Observations in humans were tested in mice using a group of sedentary mice and endurance-trained mice.
  • In mice, isolated muscle fibers were subjected to a simulated high intensity cycling scheme using electrical currents.

Results:

  • 24 hours after high intensity cycling in recreationally active men, only 15% of the ryanodine receptor 1 calcium channels remained intact, the rest were degraded.
  • 24 hours after high intensity cycling in marathon runners, ryanodine receptor 1 calcium channels were destabilized, but none were fragmented.
  • 24 hours after high intensity cycling in marathon runners, antioxidant (superoxide dismutase 2 and catalase) levels were twice as high compared to levels in recreationally active men.
  • Maximum muscle contraction force decreased after the high intensity cycling bouts independent of neural activation.
  • Isolated fibers did not have reduced contractile function after high intensity cycling.
  • In mice, reactive oxygen (a free radical) levels were substantially higher in sedentary control mice than in endurance-trained mice after simulated high intensity training.
  • Ryanodine receptor 1 fragmentation was present in sedentary mice as it was in recreationally active men after simulated high intensity training, but not when muscles were exposed to an antioxidant before and during contractions.
  • In sedentary mice, simulated high intensity training resulted in a prolonged increase in resting calcium levels which was not present in endurance-trained mice.

Limitations:

  • The study was limited to men, so whether the results are applicable to women remains unclear.
  • Age effects were not considered as part of the study.
  • Although the study indicates that high intensity training increases free radicals, results in calcium channel degradation and calcium leakage, the experiments that show increased calcium leakage and support free radicals as a causative agent of this leakage (by applying an antioxidant) were only performed in mice.
  • Although previous studies indicate that excess calcium leakage from the sarcoplasmic reticulum can lead to increased mitochondria production and thus increased energy for muscle cells, these ideas were not directly tested in this study.

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Resistance Training Prevents Brain Lesions in the Elderly

White Matter Lesions (WMLs)
from Smith et al., 2004

In older populations both cognitive function (mental capacity) and balance/coordination/walking speed tend to decline, placing these individuals at greater risk for falls and fractures and contributing to an overall lower quality of life with increased medical expenses. Impaired cognitive function and falls are associated with white matter lesions (WMLs) in the brain and this association suggests that the WMLs may at least in part cause the cognitive decline and higher incidence of falls. In a recent study (Bolandzadeh et al., 2015), scientists proposed that resistance training (weight training) would help reduce WMLs and thereby preserve cognitive function and movement patterns in older populations.

The Takehome: In women aged 65-75, 12 months of resistance training (performed twice a week) resulted in a reduction in WMLs. These reductions were significantly correlated with an ability to maintain their initial walking (gait) speed as measured at the beginning of the study. Thus, resistance training slowed the development of WMLs in the brain and helped maintain balance/coordination in the elderly. It is important to note that training without weights and training with weights only once a week did not give these results. A link between twice-weekly resistance training and improved cognitive function was not found in this study as only one test was used and the results were not significant. However, given that numerous studies associate WMLs with cognitive decline, it is likely that twice weekly resistance training counteracted this decline in some form. Nevertheless, future studies will be needed to confirm directly.

STUDY DETAILS:
Experimental Design:

  • The study duration was 52 weeks.
  • Women aged 65-75 with no resistance training history over the past 6 months were randomly assigned to one of three experimental groups.
  • Quadricep strength (isotonic) one repetition maximum and peak muscle power were measured using a leg press machine before the study began.
  • Experimental groups were as follows: Once weekly resistance training (1xRT) – 18 participants, twice weekly resistance training (2xRT) – 13 participants, twice weekly balance and tone (BAT) – 11 participants.
  • Resistance training (RT) consisted of a combination of machine training (bicep curls, tricep extensions, seated rows, latissimus dorsi pull-downs, leg presses, hamstring curls, and calf raises) with a work range of 6-8 repetitions for two sets total. Over time the intensity was increased. Free weight exercises as well as mini-squats, mini-lunges, and lunge walks were also used.
  • BAT training consisted of stretching, range of motion practice, basic core strength exercises, balance training, and relaxation exercises. BAT participants served as controls for the RT groups.
  • The Stroop Color Word Test was used to assess cognitive function. This test requires participants to read out a variety of color words printed in different colors (i.e., the word red printed in blue ink).
  • White Matter Lesions (WML) are small areas of the brain that appear very bright when imaged by MRI.

Results:

  • The 2xRT group had significantly lower WML volume than the BAT group.
  • There was no difference in WML volume between the 1xRT and BAT groups.
  • In both the 1xRT and 2xRT groups, reduced WML volume was significantly correlated with being able to maintain gait (walking) speed over the course of the study.
  • Change in WML volume was not significantly associated with a change in Stroop Color Word performance.

Limitations:

  • Only women were examined in the study, so the results may be different for men.
  • The sample size in this study was low.
  • The specific combination of machine training and free weight training was not detailed, nor were the the specific loads or sets used over time detailed.
  • The specific combination of BAT techniques were not specified.
  • The Stroop Color Word Test data was inconclusive and additional measures of cognitive function were not used so the link between resistance training, WMLs, and cognitive function remains unclear.
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Fascia May Contribute to Delayed Onset Muscle Soreness

Unpleasant muscle soreness often arises after performing exercises that are new, that have not been performed in a long time, or that include a large volume of eccentric contraction (muscle contracting/shortening against its lengthening, as when you lower yourself down from the top of a pull-up). In many cases, the pain from these exercises does not appear immediately, but surfaces a day or two later, giving rise to the term Delayed Onset Muscle Soreness (DOMS). Once DOMS has set in, pain occurs whenever the affected muscle is moved, stretched or pressed. A variety of prior studies have looked at DOMS and damage to the muscle fibers was a fairly consistent observation. However, the specific areas within the muscle that were found to be damaged and the presence of inflammation has not been consistent among studies. Therefore, many researchers believe we are missing part of the picture. In a recent study by Lau et al. (2015), findings suggest that DOMS may result more from fascia damage than muscle damage.

The Takehome: Delayed onset muscle soreness is generally attributed to muscle damage, but fascia, connective tissue that separates, encloses and supports muscle, might also be important. This study could not immediately look at muscle and fascia’s contribution to delayed onset muscle soreness (DOMS), though. The authors first had to find an external (non-invasive) readout for DOMS that could be linked to a more precise readout which targets a specific tissue type. They found that pressure pain threshold (pain from pressing on the affected muscle) correlated with electrical pain threshold (EPT) read via a needle inserted into specific tissues. Therefore EPT was used to see which tissue (muscle or fascia) was more sensitive to pain after eccentric exercise that resulted in DOMS. The authors observed that changes in pain from pressing the muscle correlated with changes in electrical pain thresholds in the fascia, but not in the muscle itself. In addition, as time progressed after exercise, fascia tended to be more sensitive to this electrical stimulation (maintaining a lower pain threshold) than the muscle. The study is a pairing of associations and correlations, but the authors present a lot of data to support the relevance of their model and don’t over-interpret their results. Their findings suggest that fascia is a greater contributor to pain from DOMS that muscle, but fascia and muscle are intricately linked, so more research is needed to see if the two are truly independent.
 
STUDY DETAILS:
Experimental Design:

  • 10 Men (ages 22-28) with no resistance training of upper arm for the past 6 months.
  • 2 exercise bouts (separated by 4 weeks) were performed.
  • Exercise was 10 sets of 6 isokinetic (constant speed) eccentric elbow flexor contractions on a dynanometer.
  • Elbows were forcibly extended from 60 degrees by the machine while subjects tried to maximally resist the extension.
  • Indirect markers of muscle damage were voluntary isometric contraction torque (MVC), range of motion of the elbow joint (ROM), muscle soreness assessed by visual analogue scale (VAS), pressure pain threshold (PPT), and electrical pain threshold (EPT). Markers were assessed before, after, and 1-5 days after exercise.
  • Tissues examined were: biceps brachii fascia (BBF), biceps brachii muscle (BBM), and brachialis fascia (BF).

Results:

  • Muscle damage markers were, as expected for repeated bouts of eccentric exercise, less prominent after the 2nd bout of eccentric exercise than after the 1st (e.g., VAS increased after both bouts and PPT and decreased after both bouts, but the magnitudes were smaller for the second bouts as compared to the first).
  • A comparison of BBF, BBM, and BF indicated that after the initial bout of exercise, electrical pain threshold decreased (pain tolerance worsened) more in the fascia (BBF, BF) than in the muscle (BBM).
  • There was a significant correlation between electrical pain threshold (EPT) and physical pain threshold (PPT) of both the BBF and BF 1 and 2 days after the first exercise bout. This correlation was not present for the muscle itself.

Limitations:

  • Women were not included in the study, so sex-differences cannot be accounted for.
  • Life-history of arm training (particularly eccentric work) was not accounted for in the study and might yield different results if training history were different (extensive training vs no training).
  • Of all the markers for damage/pain, only EPT can be measured separately on fascia or muscle. All other markers are a readout of fascia and muscle combined.
  • Cause and effect cannot be conclusively established in this type of study as there was no way to separately damage the muscle and fascia.
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Science for Fitness is a Top Fitness Blog of 2015

It’s always great to get some outside recognition. Science for Fitness made it onto two Top Fitness Blogs of 2015. One is by Wealthy Gorilla and the other is by the Institute for the Psychology of Eating. Click on the images below to see the full lists:

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