The S&C-related Studies Thread

[Eric Brown]

Damn arlecchino. I won't have to look for reading material for the next week.

Just wait until I get to the hormonal response to training shit.



Tons of neural stuff as well.

If there is anything specific that someone is interested in, let me know. I may just have something and forget to post it.

 

[belph]

Should I be reading these ?

 

[miaou]

Just wait until I get to the hormonal response to training shit.



Tons of neural stuff as well.

If there is anything specific that someone is interested in, let me know. I may just have something and forget to post it.

Great stuff man. I will eventually get around to looking through all of that.

If you think any specific studies might be particularly interesting, feel free to add your commentary.

 

[Modern Warrior1]

Stickied!!!!!!!!

 

[Eric Brown]

Motor Unit Recruitment/Training Effect:

Adjustments differ among low-threshold motor ... [J Neurophysiol. 2009] - PubMed - NCBI
Effect of temperature on spike-triggered aver... [J Appl Physiol. 2005] - PubMed - NCBI
Firing rates of motor units in human vastus l... [J Appl Physiol. 2005] - PubMed - NCBI
Motor unit control properties in constant-for... [J Neurophysiol. 1996] - PubMed - NCBI
Motor unit recruitment in human biceps brachii dur... [J Physiol. 2008] - PubMed - NCBI
Motor unit recruitment strategies investigate... [J Appl Physiol. 2002] - PubMed - NCBI
Preceding muscle activity influences motor unit di... [J Physiol. 2005] - PubMed - NCBI
Spike-triggered average torque and muscle fib... [J Appl Physiol. 2005] - PubMed - NCBI
Motor unit activity during ... [Eur J Appl Physiol Occup Physiol. 1998] - PubMed - NCBI

 

[Squat More]

I think this just may be the greatest thread in the history of S&P/S&C


I am still on holidays from work and don't train tomorrow, guess what I'll be doing. :icon_lol:

 

[Eric Brown]

Hypertrophy:

Time course for strength and muscle thick... [Eur J Appl Physiol. 2000] - PubMed - NCBI

Muscle fibre area, fibre type & capillarizat... [Can J Sport Sci. 1990] - PubMed - NCBI

Peak torque per unit cross-sectional ar... [Med Sci Sports Exerc. 1995] - PubMed - NCBI

Gaining weight: the scientific basis of i... [Can J Appl Physiol. 1999] - PubMed - NCBI

Physiological adaptations to resistance exercise.... [Sports Med. 1988] - PubMed - NCBI

Strength and power training: physiologic... [Exerc Sport Sci Rev. 1996] - PubMed - NCBI

Effect of resistance training on women'... [Med Sci Sports Exerc. 2001] - PubMed - NCBI

Physiologic responses to heavy-resistance e... [Int J Sports Med. 1987] - PubMed - NCBI

Hormonal responses to consecutive days of hea... [J Appl Physiol. 1998] - PubMed - NCBI

The time course for elevated muscle prote... [Can J Appl Physiol. 1995] - PubMed - NCBI

Gender differences in stren... [Eur J Appl Physiol Occup Physiol. 1993] - PubMed - NCBI

Exercise and training in women, Part I: I... [Can J Appl Physiol. 2000] - PubMed - NCBI

Skeletal muscle adaptations during early phas... [J Appl Physiol. 1994] - PubMed - NCBI

Muscle hypertrophy and fast... [Eur J Appl Physiol Occup Physiol. 1990] - PubMed - NCBI

Gender differences in muscular strength: ... [Biomed Sci Instrum. 1997] - PubMed - NCBI

Muscle fiber types of women after resistance t... [Pflugers Arch. 1993] - PubMed - NCBI

 

[miaou]

Study published yesterday, on the possible effects of massage on recovery. I thought this study was particularly interesting because, as far as I'm aware, this is the first study to provide solid data for it (other than subjective reports):

Massage Therapy Attenuates Inflammatory Signaling After Exercise-Induced Muscle Damage

Summary
Massage therapy is commonly used during physical rehabilitation of skeletal muscle to ameliorate pain and promote recovery from injury. Although there is evidence that massage may relieve pain in injured muscle, how massage affects cellular function remains unknown. To assess the effects of massage, we administered either massage therapy or no treatment to separate quadriceps of 11 young male participants after exercise-induced muscle damage. Muscle biopsies were acquired from the quadriceps (vastus lateralis) at baseline, immediately after 10 min of massage treatment, and after a 2.5-hour period of recovery. We found that massage activated the mechanotransduction signaling pathways focal adhesion kinase (FAK) and extracellular signal–regulated kinase 1/2 (ERK1/2), potentiated mitochondrial biogenesis signaling [nuclear peroxisome proliferator–activated receptor γ coactivator 1α (PGC-1&#945], and mitigated the rise in nuclear factor κB (NFκB) (p65) nuclear accumulation caused by exercise-induced muscle trauma. Moreover, despite having no effect on muscle metabolites (glycogen, lactate), massage attenuated the production of the inflammatory cytokines tumor necrosis factor–α (TNF-&#945 and interleukin-6 (IL-6) and reduced heat shock protein 27 (HSP27) phosphorylation, thereby mitigating cellular stress resulting from myofiber injury. In summary, when administered to skeletal muscle that has been acutely damaged through exercise, massage therapy appears to be clinically beneficial by reducing inflammation and promoting mitochondrial biogenesis.

And here is an article on that study with some more details:

Need an Excuse to Book a Massage? Massage Reduces Inflammation and Promotes Growth of New Mitochondria Following Strenuous Exercise

ScienceDaily (Feb. 1, 2012) — recovery-promoting effects of massage. Now there's a scientific basis that supports booking a session with a massage therapist: On the cellular level massage reduces inflammation and promotes the growth of new mitochondria in skeletal muscle. The research, involving scientists from the Buck Institute for Research on Aging and McMaster University in Hamilton Ontario appears in the February 1st online edition of Science Translational Medicine.


The study involved the genetic analysis of muscle biopsies taken from the quadriceps of eleven young males after they had exercised to exhaustion on a stationary bicycle. One of their legs was randomly chosen to be massaged. Biopsies were taken from both legs prior to the exercise, immediately after 10 minutes of massage treatment and after a 2.5 hour period of recovery.

Buck Institute faculty Simon Melov, PhD, was responsible for the genetic analysis of the tissue samples. "Our research showed that massage dampened the expression of inflammatory cytokines in the muscle cells and promoted biogenesis of mitochondria, which are the energy-producing units in the cells," said Melov. He added that the pain reduction associated with massage may involve the same mechanism as those targeted by conventional anti-inflammatory drugs. "There's general agreement that massage feels good, now we have a scientific basis for the experience," said Melov.

Study participants were recruited at McMaster University in Hamilton, Ontario, Canada. Lead author Mark Tarnopolsky, MD, PhD, from the Department of Pediatrics and Medicine said the research provides much needed validation for a practice that is growing in popularity. "The potential benefits of massage could be useful to a broad spectrum of individuals including the elderly, those suffering from musculoskeletal injuries and patients with chronic inflammatory disease," said Tarnopolsky. "This study provides evidence that manipulative therapies, such as massage, may be justifiable in medical practice."

About 18 million individuals undergo massage therapy annually in the U.S., making it the fifth most widely used form of complementary and alternative medicine. Despite several reports that long-term massage therapy reduces chronic pain and improves range of motion in clinical trials, the biological effects of massage on skeletal tissue have remained unclear.

(These may or may not have been the masseuses used in the study)​

Link to study - Massage Therapy Attenuates Inflammatory Signaling After Exercise-Induced Muscle Damage

Link to article - Need an excuse to book a massage? Massage reduces inflammation and promotes growth of new mitochondria following strenuous exercise

 

[SimonAdd]

Interesting article, but doesn't this:

To assess the effects of massage, we administered either massage therapy or no treatment to separate quadriceps of 11 young male participants after exercise-induced muscle damage.

leave the possibility of a placebo effect?

 

[hardheart]

Interesting article, but doesn't this:



leave the possibility of a placebo effect?

If you can devise a method to do a blind or double blind in relation to massage after a workout, I'm all ears.

 

[miaou]

Interesting article, but doesn't this:

leave the possibility of a placebo effect?

They didn't measure the effects by subjective reporting or questionnaires that could be skewed by perceptual/expectation biases; they took muscle biopsies and analyzed them for gene expression signaling factors, inflammatory factors and muscle metabolites. Whatever findings were objective results of the treatment.

Strictly speaking, you are right that there was no placebo control and you are free to hypothesize whether the results might have been influenced by it. My comment is that the placebo effect is generally related to central cognitive centers (i.e. the brain) and its physiological effects are generally mediated by the stress response and how chronic alterations in cortisol levels and sympathetic activity may impact/interact with tissues. Imo, it is unsupported by any evidence (and, based on the possible mechanisms related to placebo, probably illogical) to conclude that the placebo effect could have such a measurable result in such markers in a matter of 2 hours (if anything, lowered stress in the acute window should result in the opposite effects in terms of controlling secretion of inflammatory cytokines).

 

[miaou]

This is a review/opinion piece on exercise stimuli for hypertrophy published a couple of days ago in Applied Physiology, Nutrition, and Metabolism.

The paper pretty-much riffs off a study published last year about very-low-intensity/very-high-repetition training (I think it might have been mentioned here). Basically, the authors make the case regarding muscle hypertrophy that, as long as you approach momentary failure (in order to recruit most MUs according to the size principle), it doesn't matter what intensity you lift at (whether than is 85%, 70%, or 30%) but the only thing that counts is total volume.


Here is the abstract:

Bigger weights may not beget bigger muscles: evidence from acute muscle protein synthetic responses after resistance exercise.

Abstract
It is often recommended that heavier training intensities (∼70%-80% of maximal strength) be lifted to maximize muscle growth. However, we have reported that intensities as low as 30% of maximum strength, when lifted to volitional fatigue, are equally effective at stimulating muscle protein synthesis rates during resistance exercise recovery. This paper discusses the idea that high-intensity contractions are not the exclusive driver of resistance exercise-induced changes in muscle protein synthesis rates.

And here is a part of the full text:

Resistance exercise intensities of 70%

 

[SuperAlly]

Does anyone have any access to recent papers on the relative efficacy of static and dynamic stretching pre-exercise?

No longer a student and don't have access to the same level of research that I once did.

Found a few papers through google scholar but there from 2006? Want something to back up the assertion that dynamic is preferred pre-exercise with static post exercise (or in moderation before exercise and only after dynamic). Unless things have changed.

 

[miaou]

^ here are three recent reviews:

To stretch or not to stretch: the role of stretching in injury prevention and performance. (2010)
A review of the acute effects of static and dynamic stretching on performance. (2011)
Effect of acute static stretch on maximal muscle performance: a systematic review. (2012)


TL;DR: strength/power (and, plausibly, also proprioceptive ability) is slightly inhibited immediately after prolonged static stretching and may be slightly primed immediately after dynamic stretching. Performing some non-prolonged static stretching in your warmup (which also includes dynamic stretching, mobility drills, sport-specific drills, etc.) would have no detrimental neural effects. If you need to perform some static stretching to achieve proper ROM for the sport/activity you are about to engage in, perform as much as you have to (but no more that that, which nobody does, anyway, because static stretching before you work out is extremely boring), just do it at the beginning of your warmup before dynamic stretching/mobility/sport-specific stuff (which is what you would naturally do, anyway, if you are not a complete moron).

 

[SuperAlly]

Had another work enforced absence from the forum miaou and never saw your reply. Thanks will check through those studies. Would love to see this thread busier.

 

[Tosa]

Hey, now that this isn't a sticky, it's much more noticeable. I like those studies on stretching, Miaou. A scientific response to the anti-static stretching nonsense.

 

[miaou]

Regarding the effect of rest times between sets on muscle hypertrophy (it is commonly suggested that you should take shorter rests if your goal is hypertrophy and longer rests if you goal is strength), I recently came across a relevant study.

It's not very recent (from 2005), but I wasn't aware of it and it looks to have a good experimental design:

Short vs. long rest period between the sets in hypertrophic resistance training: influence on muscle strength, size, and hormonal adaptations in trained men.

Abstract
Acute and long-term hormonal and neuromuscular adaptations to hypertrophic strength training were studied in 13 recreationally strength-trained men. The experimental design comprised a 6-month hypertrophic strength-training period including 2 separate 3-month training periods with the crossover design, a training protocol of short rest (SR, 2 minutes) as compared with long rest (LR, 5 minutes) between the sets. Basal hormonal concentrations of serum total testosterone (T), free testosterone (FT), and cortisol (C), maximal isometric strength of the leg extensors, right leg 1 repetition maximum (1RM), dietary analysis, and muscle cross-sectional area (CSA) of the quadriceps femoris by magnetic resonance imaging (MRI) were measured at months 0, 3, and 6. The 2 hypertrophic training protocols used in training for the leg extensors (leg presses and squats with 10RM sets) were also examined in the laboratory conditions at months 0, 3, and 6. The exercise protocols were similar with regard to the total volume of work (loads x sets x reps), but differed with regard to the intensity and the length of rest between the sets (higher intensity and longer rest of 5 minutes vs. somewhat lower intensity but shorter rest of 2 minutes). Before and immediately after the protocols, maximal isometric force and electromyographic (EMG) activity of the leg extensors were measured and blood samples were drawn for determination of serum T, FT, C, and growth hormone (GH) concentrations and blood lactate. Both protocols before the experimental training period (month 0) led to large acute increases (p < 0.05-0.001) in serum T, FT, C , and GH concentrations, as well as to large acute decreases (p < 0.05-0.001) in maximal isometric force and EMG activity. However, no significant differences were observed between the protocols. Significant increases of 7% in maximal isometric force, 16% in the right leg 1RM, and 4% in the muscle CSA of the quadriceps femoris were observed during the 6-month strength-training period. However, both 3-month training periods performed with either the longer or the shorter rest periods between the sets resulted in similar gains in muscle mass and strength. No statistically significant changes were observed in basal hormone concentrations or in the profiles of acute hormonal responses during the entire 6-month experimental training period. The present study indicated that, within typical hypertrophic strength-training protocols used in the present study, the length of the recovery times between the sets (2 vs. 5 minutes) did not have an influence on the magnitude of acute hormonal and neuromuscular responses or long-term training adaptations in muscle strength and mass in previously strength-trained men.

What this says is that, for training aimed at increasing hypertrophy, the two different groups did the same training volume with 2- vs 5-minute breaks between sets for 3 months and there were no significant differences in the increases in hypertrophy and isokinetic strength for the quads.

 

[bowlie]

Regarding the effect of rest times between sets on muscle hypertrophy (it is commonly suggested that you should take shorter rests if your goal is hypertrophy and longer rests if you goal is strength), I recently came across a relevant study.

It's not very recent (from 2005), but I wasn't aware of it and it looks to have a good experimental design:




What this says is that, for training aimed at increasing hypertrophy, the two different groups did the same training volume with 2- vs 5-minute breaks between sets for 3 months and there were no significant differences in the increases in hypertrophy and isokinetic strength for the quads.

I guess the increases intensity you can use from being fully rested balances out the loss of cumulative fatigue? Is it just me or is strength incredibly dominant over conditioning in this thread? If you have anything on the relationship between strength and endurance i would be very interested in it. As far as i can see, its easy to understand how to get stronger (although doing it requires a huge input of energy and commitment). How to reconcile the contradictions of power and endurance in such a way that you can get stronger and more powerful, while improving or at least maintaining your ability to apply that strength over the course of a series of rounds is what i find the hard, and interesting, part of S&C for combat sports.

 

[tsukongk]

Two studies

Intermittent versus constant aerobic exercise: effects on arterial stiffness.
http://www.ncbi.nlm.nih.gov/pubmed/21081799

The study was done on humans, with the conclusion that interval training lowers arterial stiffness better compared to constant state. Found it interesting if your goal is indeed circulatory system improvements and not just losing weight (which HIIT is also effective at).

Ibuprofen administration during endurance training cancels running-distance-dependent adaptations of skeletal muscle in mice.
http://www.ncbi.nlm.nih.gov/pubmed/21081799

As the title implies, it would appear that ibuprofen makes long distance running less effective. I found it interesting in the sense that some people will pop NSAIDs to allow them to train sooner or longer. The study implies(at least for rats) that this may be counter productive. (in before DUH)

 

[miaou]

I guess the increases intensity you can use from being fully rested balances out the loss of cumulative fatigue?

Or maybe cumulative fatigue is not the deciding factor.

Is it just me or is strength incredibly dominant over conditioning in this thread? If you have anything on the relationship between strength and endurance i would be very interested in it. As far as i can see, its easy to understand how to get stronger (although doing it requires a huge input of energy and commitment). How to reconcile the contradictions of power and endurance in such a way that you can get stronger and more powerful, while improving or at least maintaining your ability to apply that strength over the course of a series of rounds is what i find the hard, and interesting, part of S&C for combat sports.

Fair enough. I mostly post here studies I recently came across that I found interesting. It appears I haven't come across many conditioning-related studies recently that I thought were interesting enough to post here. People are always welcome to post things they thought are worth reading/discussing about, this is not a private-blog-type thread. EDIT: or, if there is a specific subject you want to discuss, you can start a thread specifically about it.

Btw, imo, building your conditioning is no more complicated or less straight forward than building your strength. Programming your training to develop both qualities is another matter, and it is one where there aren't all that many studies produced to be posted here. I think I included a link to a relevant study in the Conditioning FAQ as a starting point; if you want to make a search by yourself you can use the term "concurrent training" as your keyword and post any studies you think are relevant and interesting.