LED Therapy: 30% Increase in Max. # of Reps in New Study, Increased Stamina and More Recent LLLT / LEDT Data

LED Therapy: 30% Increase in Max. # of Reps in New Study, Increased Stamina and More Recent LLLT / LEDT Data

laser therapy LED LEDT leg training LLLT low level laser therapy performance quadriceps recovery

The scientists used an LEDT device from Thor on two points on the distal portion of the vastus lateralis, two points on the distal portion of the vastus medialis and two centered points along the rectus femoris (see Figure 1, right).

It may be partly my fault that most of you ask me for supplements to take to increase their performance and do not expect often not even consider the possibility of being told about technological items like a low-level laser diode device to up their gains or boost their fat loss...

When I started this blog a few years ago, I was guilty of believing that supplements would be the most relevant ergogenics for anyone who trains, myself. Today, ~2,300 articles later, this has changed: don't get me wrong - supplements can be useful, but diet, training and - at least in a few cases - even things like using light emitting diode therapy (LEDT) or low-level laser therapy (LLLT), as it is also called, are much higher on the "things that really work"-list.

Read more short news at the SuppVersity to learn more about training & nutrition.

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In that, it is important to point out that a recent study from the Georgia Southern University (Hemmings. 2016) is neither the first study to show significant performance / recovery benefits from LEDT, nor is it the first study I wrote about (read previous articles). The experiment Hemmings et al. conducted is yet the first to evaluate the effects of different dosages of LEDT (30 vs. 60 vs. 120 seconds on each irradiation point, see Figure 1, right) that was applied by the means of a low-level laser (THOR, London, UK) on muscular fatigue of the quadriceps after two sets of three maximal voluntary isometric contractions (MVIC).

Figure 1: Comparison of repetitions and blood lactate concentrations between all four trials; illustration of the irradiation points that were used for LEDT (Hemmings. 2016)

A total of 34 recreationally resistance trained athletes between the ages of 18 and 26 participated in four trials. Each trial included pre/post exercise blood lactate measurements, the previously hinted at MVIC and a single set of eccentric leg extensions (at 120% of the previously determined MVC) to exhaustion that was done three minutes after the initial exercises and used as a yard-stick for the recovery benefits of using 30s, 60s and 120s of LEDT compared to a 45s placebo treatment of which the subjects thought that it was yet another irradiation time that was to be tested.

LLLT therapy has also been shown to almost double the muscle gains in a study with an 8-week eccentric training program | more

LLLT and LEDT - What does the science say?: Here's how the authors explain the difference, between different forms of laser light therapy (LLT) and light emitting diode therapy (LEDT): "The difference between LLT and LEDT is the power output and depth of penetration due to various patterns in wavelengths" (Hemmings. 2016). The potential mechanism, on the other hand is always the same: "[r]esearch suggests that LLLT can prolong the binding of nitric oxide to the cytochrome C oxidase enzyme, which permits the muscle to produce more ATP in the preferred oxidative pathway" (Hemmings. 2016).

A recent meta-analysis (Nampo. 2016) evaluated both, the effects of LLLT and LEDT, on exercise capacity and muscle performance of people undergoing exercise when compared to placebo treatment. Sixteen studies involving 297 participants were included in the meta-analysis that shows a mean improvement of the number of repetitions of 3.51 reps (0.65–6.37; P = 0.02), a 4,01 second delay in time to exhaustion (2.10–5.91; P < 0.0001), and - unlike the study at hand - a sign. reduction in lactate levels (MD = 0.34 mmol/L [0.19–0.48]; P < 0.00001) and increased peak torque (MD = 21.51 Nm [10.01–33.01]; P < 0.00001).

Exercise capacity - Number of reps (left), time to exhaustion (right | Nampo. 2016)

Reason enough for the authors to conclude that their "results suggest that LASERtherapy is effective in improving skeletal muscle exercise capacity" - one thing Nampo et al. rightly add is that "the quality of the current evidence is limited" (Nampo. 2016).

As you would expect it for any effective ergogenic, the scientists observed a "significant increase in the number of repetitions performed between the placebo treatment" (Hemmings. 2016). In that, it is interesting to see that both treatments, i.e. 60 seconds (p= 0.023), as well as the 120 seconds (p=0.004) LEDT treatment triggered a significant increase in the number of reps the subjects completed - without, however, significantly affecting the accumulation of blood lactate levels in the subjects' blood. Another thing the data in Figure 1 tells us that must not be forgotten is the lack of effect of applying LEDT for only 30 seconds per irradiation point (see Figure 1, right).

Lactate is not the enemy - remember? Caffeine and Bicarbonate (NaHCO3), two proven ergogenics increase, not decrease blood lactate accumulation while still boosting subjects' performance during a standardized yo-yo performance test | learn more.

While the last-mentioned lack of effect of a shorter treatment is probably something you'd expect, the lack of effect on the accumulation of lactate may come as a surprise. Eventually, however, the exercise duration was probably simply too short to accumulate exuberant lactate levels. It is imho also questionable why the scientists used lactate, not CK or another potential measure of muscle damage (or a biopsy) to judge the effects of the LEDT treatment on a molecular level. After all, the often-heard hypothesis that the accumulation of lactate would be the reason you fail due to muscular exhaustion is - in view of the existing evidence - at least questionable.

What about gains and does timing matter? No, you don't have to be afraid that LLLT would have the same negative effects on your gains as ice-baths. It has, after all, already been shown to double the gains in a 2015 8-week study in healthy volunteers | read more! And the timing, yeah... Well, yes timing does matter! You have to apply it before the workout to see effects... at least for immediate 1RM strength gains this is the case according to a very recent study by Vanin (2016) - future studies will tell if using it post, as a recovery tool can be effective in the long-term.

As a SuppVersity reader you will, for example, remember that proven ergogenics such as bicarbonate and beta alanine increase the accumulation of lactate significantly... ok, you may argue that they simply protect the muscle from the tiring effects of lactate, but eventually there are other more likely candidates to explain the onset of fatigue such as the accumulation of other muscle metabolite, a decrease in free energy of adenosine triphosphate, limited O2 or other substrate availability, increased glycolysis, pH disturbance, increased muscle temperature, reactive oxygen species production, and altered motor unit recruitment patterns (Grassi. 2015; Poole. 2015), which could eventually explain why our muscles fatigue and why the lactate levels increase (reduced ATP, for example, will necessarily increase glycolysis and eventually the lactate accumulation).

This is only one of of several LLLT studies I've discussed in detail in older SV articles. Examples? What about this one from Aug 2015: Phototherapy Doubles Fat Loss (11 vs. 6%) & Improvements in Insulin Sensitivity (40 vs. 22%) and Helps Conserve Lean Mass in Recent 20 Weeks 'Exercise for Weight Loss Trial' | read more

Bottom line: Yeah, the scienists are right to conclude that "light emitting diode therapy had a positive effect on performance when irradiating six points on the superficial quadriceps for 60 seconds and 120 seconds prior to an eccentric leg extension" (Hemmings. 2016).

What can be refuted based on their results, however, is that this effect was a consequence of reduced lactate levels. That's in contrast to another recent study in a particularly vurnerable subgroup of hobby athletes, i.e. the hospitalized patients with heart failure in a pilot study by Bublitz et al. who found a significant decrease in lactate accumulation, albeit in response to a 6-minute walking exercise, during which LLDT was able to reduce the subjective fatigue and the previously discussed lactate concentrations, but not the subjects' performance.

Overall, it seems reasonable to conclude that further research is necessary to (a) elucidate the underlying mechanism behind the (pro-)recovery / performance enhancing effects, as well as LEDT's / LLLT's previously reported beneficial effects on insulin sensitivity and body composition and the most promising areas of application (according to the study at hand this could be resistance training / any sport that requires maximal anaerobic performance) | Comment!

References:

• Bublitz, Caroline, et al. "Acute effects of low-level laser therapy irradiation on blood lactate and muscle fatigue perception in hospitalized patients with heart failure—a pilot study." Lasers in medical science (2016): 1-7.
• Byrne, Christopher, Craig Twist, and Roger Eston. "Neuromuscular function after exercise-induced muscle damage." Sports medicine 34.1 (2004): 49-69.
• Grassi, Bruno, Harry B. Rossiter, and Jerzy A. Zoladz. "Skeletal muscle fatigue and decreased efficiency: two sides of the same coin?." Exercise and sport sciences reviews 43.2 (2015): 75-83.
• Hemmings, Thomas J. "Identifying Dosage Effect of LEDT on Muscular Fatigue in Quadriceps." Journal of Strength and Conditioning Research (2016): Publish Ahead of PrintDOI: 10.1519/JSC.0000000000001523..
• Poole, David C., and Thomas J. Barstow. "The critical power framework provides novel insights into fatigue mechanisms." Exercise and sport sciences reviews 43.2 (2015): 65-66.
• Vanin, Adriane Aver, et al. "What is the best moment to apply phototherapy when associated to a strength training program? A randomized, double-blinded, placebo-controlled trial." Lasers in Medical Science (2016): 1-10.

Human Study Provides New Insight into How NSAIDs Speed Up Satellite Cell Recruitment & Muscle Repair in Youngsters

Human Study Provides New Insight into How NSAIDs Speed Up Satellite Cell Recruitment & Muscle Repair in Youngsters

aspirin build muscle COX II ibuprofen NSAID NSAIDs recovery satellite cells

No, I still do not recommend the chronic (ab-)use of NSAIDs, bro.

No, this is not the first study about the effects of NSAIDs on muscle gains I discuss here at www.suppversity.com, but it is certainly one of the more interesting ones. The study which is about to be published in the FASEB Journal was designed to investigate the role of nonsteroidal anti-inflammatory drugs (NSAIDs) in human skeletal muscle regeneration.

As you may remember, previous studies have yielded conflicting evidence with respect to the ability of NSAID to accelerate muscle healing and thus accelerater and ultimately shorten the adaptational process.

Hormesis is why soothing the inflammation is not always good for athletism

Is Vitamin E Good for the Sedentary Slob, Only?

Even Ice-Baths Impair the Adapt. Process

Vit C+E Impair Muscle Gains in Older Men

C+E Useless or Detrimental for Healthy People

Vitamin C and Glucose Management?

Antiox. & Health Benefits Don't Correlate

In the study at hand, the authors did therefored recruit 32 untrained, but healthy young men and randomly assigned them to consume either NSAID [1200 mg/d ibuprofen (IBU)] or placebo (PLA) daily for 2 wk before and 4 wk after an electrical stimulation–induced injury to the leg extensor muscles of one leg.

To assess, whether the ingestion of ibuprofen would, as the scentists suspected alter satellite cell response and time course of regeneration in the experimentally injured skeletal muscle of young healthy men, biopsies were collected from the vastus lateralis muscles before and after stimulation (2.5 h and 2, 7, and 30 d) and were assessed for satellite cells and regeneration by immunohistochemistry and real-time RT-PCR. In conjunction with the likewise measured length of the telomeres, the scientists expected to be able to determine the actual effect of NSAIDs on the post-exercise recovery process.

Figure 1: CD68 and CCL2 are only two markers of the damage/repair process that show a clear phase-shift (meaning earlier elevation = earlier repair) with IBU. Furthermore the ibuprofen "preload" prevented the formation of collage (right) in the muscle after 30 days (Mackey. 2016).

What the researchers found was appears to be a clear advantage... initially: After injury, and compared with PLA, IBU was found to augment the proportion of ActiveNotch1+ satellite cells at 2 d [IBU, 29 +/- 3% vs. PLA, 19 +/- 2% (means +/- SEM)], satellite cell content at 7 d [IBU, 0.16 +/- 0.01 vs. PLA, 0.12 6 0.01 (Pax7+ cells/fiber)], and to expedite muscle repair at 30 d.

The bad news is that the chronic consumption of NSAIDs is nothing a healthy individual should consider - even if it prevents your muscle from collagen depositions (see Figure 1, right); and still, if we could get the benefits observed in the study at hand without the potential long-term side effects of common NSAIDs, they could be a game changer... at least for elderly individuals, in whom the recruitment of satellite cells and thus process of muscle repair appears to be impaired by aging.

The statement that NSAIDs could be particularly beneficial for elderly is more than an unsupported hypothesis. In February, I already wrote about the type-I-specific muscle-building effects of COX-inhibitors | learn more.

So what? No, this is not an endorsment of NSAIDs and I still cannot recommend the chronic ingestion of NSAIDs as muscle builders. I have to admit, though, that I am pretty impressed by the way ibuprofen helped the repair of myofibers in the later stages of regeneration and mediated a more rapid return of satellite cells and muscle extra-cellular matrix (ECM) gene expression levels to baseline values.

As Mackey et al. point out, NSAIDs (in this case IBU) is eventually shifting the entire time course of satellite cell, myofiber - and that without effects on muscle telomere length in human skeletal muscle in vivo. In view of the highly damaging electrostimlation method, it does yet remain to be seen how beneficial effect of NSAID ingestion are when the damate to the muscle is less pronounced and thus in a more physiological range  | Leave a comment and tell me what you think on Facebook!

References:

• Mackey, Abigail L., et al. "Activation of satellite cells and the regeneration of human skeletal muscle are expedited by ingestion of nonsteroidal anti-inflammatory medication." The FASEB Journal (2016): fj-201500198R.

Recovery Cocktail With Vitamins C+E, Ibuprofen, Cold Water Immersion and Whey Works - Long-Term Effects? Unknown!

Recovery Cocktail With Vitamins C+E, Ibuprofen, Cold Water Immersion and Whey Works - Long-Term Effects? Unknown!

antioxidants cold water immersion gains passive recovery performance recovery vitamin C vitamin E vitamins

What's the right strategy to boost workout recovery? A recent study suggests that it could be a mix of NSAID, antioxidants, cold water and whey.

Vitamin C + E, ibuprofen, cold water immersion and whey? Two of these agents have been shown to impair the adaptational response to exercise and thus potentially compromise long-term gains (vitamin C+E and cold water immersion). The other two are either purported (ibuprofen) or proven (whey) ergogenics - ergogenics of which a recent study by scientists from the Hashemite University in Jordan and the University of Alabama in the USA shows that their combination with the formerly named agents is "helpful in protecting performance" in a test during which the competitive athletes (current or former Division I college athletes / club athletes) performed two bouts of high-intensity anaerobic cycling separated by 30 minutes of rest.

Learn more about hormesis and how antioxidants can also impair your gains

Is Vitamin E Good for the Sedentary Slob, Only?

Even Ice-Baths Impair the Adapt. Process

Vit C+E Impair Muscle Gains in Older Men

C+E Useless or Detrimental for Healthy People

Vitamin C and Glucose Management?

Antiox. & Health Benefits Don't Correlate

The participants had been randomly assigned in counterbalanced order to start the first week as a treatment or as a control (nontreatment).

• In the treatment trial, participants were provided with 2 oral doses of 1,000 mg of vitamin C (ascorbic acid with citrus bioflavonoids; General Nutrition Corp., Pittsburgh, PA, USA) and 400 IU of vitamin E soft gel capsules (d-a-tocopherol; General Nutrition Corp.). The first dose was taken with dinner the night before the exercise protocol, and the second dose was taken on the morning of the exercise test. The morning doses were consumed at least 1 hour before the blood sample was taken. Ibuprofen doses (400 mg; 2 ADVIL liquigels, 200 mg capsules; Wyeth Consumer Healthcare, Madison, NJ, USA) were given to participants 30 minutes before each exercise session. The protein supplement, 23 g of whey protein (10.6 g essential amino acids [EAA], 7.3 g of conditionally EAA, and 5.6 g of non EAA ON Sunrise, FL, USA), was mixed with 200 ml of skimmed milk to form a protein shake. The protein shake was given to participants within 3 minutes of finishing each exercise session in the treatment trial. Three to 5 minutes after the end of each exercise session, participants submerged their lower body in cold (10–12.58 C) water for 10 minutes.
• In the control trial, the subjects performed the same testing protocol consisting of 2 exercise sessions with 6.5–7 hours between AM and PM sessions to replicate morning and afternoon workouts or heats. 

The exercise tests were 2-bout sessions that began with a 15-minute warm-up (stretching and cycling). Each bout consisted of three 30-second Wingate power tests with 3 minutes of active recovery (60 RPM with no resistance) in between. After the 27th minute, a second warm-up for 3 minutes preceded the second Wingate bout for a total of six 30-second Wingate tests per session (Figure 1).

Figure 1: Representation for the Wingate test daily order (Al-Nawaiseh. 2016).

"All Wingate tests were performed using 7.5% of body weight as a resistance. The resistance was applied to the ergometer (E224 Monark) after a 10-second countdown. Participants used the countdown time to accelerate peddling speed. [...] Participants rated their RPE and muscle soreness sensation (pain) before and after each Wingate test. Muscle soreness was assessed using a 10-cm visual analog scale with anchor points “no pain at all” at the left end and “unbearable pain” at the right end. Rated perceived exertion was determined using a 6–20 point scale" (Al-Nawaiseh. 2016).

When they had volunteered for the study, all participants had been asked to quit any kind of exercise and all kinds of supplements 48 and 72 hours before exercise protocols, respectively.

Intense training sessions will always increase ALT, AST & CK - in some cases to extreme values that are 10-100x above "normal". Unfortunately doctors will never learn that in med-school and may misinterpret these changes as indicators of organ failure | learn more!.

Which markers of recovery are actually useful? A recent study from the Federal University of Uberlandia (UFU) in Brazil says (Bessa. 2016): "The best way to use biomarkers to monitor athletes is to perform a screening test like the test we have performed in this experiment, using the type and intensity of exercise commonly practiced by the athletes" (Bessa. 2016). Which test? Well, the study investigated CK, LDH, cardiac troponin T (cTnT), g-glutamyltransferase (gGT), and C-reactive protein (CRP), interleukin-6 (IL-6), MCP-1, and tumor necrosis factor (TNF)-alpha, the neutrophil to lymphocyte ratio, GPX, SOD, CAT, TAS and TBARS immediately before and 3, 6, 12, 24, 48, and 72 hours after exercise. The parameters the scientists consider most useful, however, were: (1) CK (not LDH) plus a differential analysis based on cTnT (cardiac CK), gGT (liver), hematocrit, and platelet levels that is used to make sure the increase in CK is coming solely from muscle damage and (2) the leukocyte to neutrophil ratio as a marker of the progress of the supercompensation process after workouts.

Accordingly, we can expect that the improved mean wattage in the supplement trial is the result of the wicked mix of antioxidants, pain killers, cold water immersion and whey the subjects had to stomach / endure.

Figure 1: The treatment (orange) ameliorated the decrease in mean and minimum power during the PM Wingate trial that was performed after the ingestion of antioxidants, ibuprofen, and whey and cold water immersion (Al-Nawaiseh. 2016).

What is quite surprising about these improvements is that they occured in the absence of reduced perceived pain scores / fatigue during the PM sessions. In conjunction with the lack of significant effects on muscle CK in the blood (not shown in Figure 2), this observation warrants the authors conclusion that the observed effects on the subjects' performance were "apparently not due to reduced muscle soreness or damage" (Al-Nawaiseh. 2016). That's in contarst to previous studies like

• Pizza et al. (1999), who reported that similar ibuprofen doses lowered CK activity relative to a placebo 3 days after eccentric arm exercise, or
• Tokmakidis et al. (2003), who found that ibuprofen doses (400 mg every 8 hours for 48 hours) did lower the non-athletic subjects' CK levels and reduced their muscle soreness, without, however, helping to restore muscle function compared with placebo.

Whether these difference are the mere result of differences in the way the exercise / tests were timed (vs. Pizza et al.) or differences in the training level of the subjects, as well as the exercise and testing protocols (vs. Tokmakidis et al.) will have to be tested in future studies.

Bottom line: As the scientists points out in the conclusion to their study, their results "suggest that although the combined use of ibuprofen, cryotherapy, vitamins C and E, and protein drink did not significantly help in protecting from muscle damage and soreness, the combination did help in restoring important muscle function and boosted short-term recovery from high-intensity anaerobic performance" (Al-Nawaiseh. 2016).

Using Ice / Cold Water Immersion After Workouts Will Impair Muscle and Strength Gains, as well as Vascular Adaptations | more

Practically speaking, athletes who compete in events that require repeated anaerobic performance (over 24h) should thus benefit from the combined use of antioxidant vitamins, an NSAID (ibuprofen), 10 minutes of lower body cold water submersion, and 23 g whey protein (10 g EAA).

What you should not forget, however, is the fact that at least 2 of the 4 'ingredients' of this 'recovery cocktail' have been shown to inhibit the long(er)-term adaptation to exercise. The chronic use of cold water immersion and high(er) doses of vitamin C + E in conjunction with exercise can thus not be recommended... and if you care about organ and cartilage health, the same goes for the use of NAIDs | Comment!

References:

• Al-Nawaiseh, Ali M., Robert C. Pritchett, And Philip A. Bishop. "Enhancing Short-Term Recovery After High Intensity Anaerobic Exercise." The Journal Of Strength & Conditioning Research (2015).
• Bessa, Artur, et al. "Exercise intensity and recovery: Biomarkers of injury, inflammation and oxidative stress." J. Strength Cond. Res (2016).
• Pizza, F. X., et al. "Anti-inflammatory doses of ibuprofen: effect on neutrophils and exercise-induced muscle injury." International journal of sports medicine 20.2 (1999): 98-102.
• Toakmatidis, Savvas P., et al. "The effects of ibuprofen on delayed muscle soreness and muscular performance after eccentric exercise." The Journal of Strength & Conditioning Research 17.1 (2003): 53-59.

Muscle Regeneration & Hypertrophy Update: Vitamin D and Super-Slow Training - What Are They Good For?

Muscle Regeneration & Hypertrophy Update: Vitamin D and Super-Slow Training - What Are They Good For?

25(OH)D build muscle calcitriol D3 recovery regeneration skeletal muscle super slow tut vitamin D vitamin D3

Is it worth to replete vitamin D, but not to train super-slow, right?

No, I haven't dug up a study that deals with vitamin D and super-slow training at once, but I've found two very recent studies that are in one way or another related to muscle regeneration and hypertrophy and the way/s vitamin D and different training methods affect these outcomes. More specifically, the researchers investigated the effects of vitamin D (20OHD) repletion and the use of higher times-under-tension (TUT) and super-slow training.

Before I go ahead, though, I would like to point out that the long-term implications of some of the results are not totally obvious - a fact I will therefore (re-)address in the bottom line.

If you periodize appropriately you may actually be able to benefit from super-slow training.

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• (Super-)slow training and its inferior effects on early-phase satellite cell and myonuclear domain adaptation (Herman-Montemayor. 2015) -- The purpose of one of the latest studies from the Rocky Vista University was to identify adaptations in satellite cell (SC) content and myonuclear domain (MND) after 6-week slow-speed vs. “normal-speed” resistance training programs.
  
  To this ends, thirty-four untrained women were divided into slow speed (SS), traditional strength (TS), traditional muscular endurance (TE), and nontraining control (C) groups. The ladies performed a leg work consisting of three sets of each of the following exercises twice per week in the first and thrice per week in the fifth week: Leg press, squat, and knee extensions. To investigate how the way these workouts were performed would affect the adaptive response, the scientists randomly assigned their subjects to four different groups:
  • The Super-Slow (SS) group performed 6– 10 repetition maximum (6–10RM) for each set with 10-second concentric (con) and 4-second eccentric (ecc) contractions for each repetition.
  • The Traditional Strength (TS) group and the Traditional Muscular Endurance (TE) group who performed 6–10RM and 20–30RM, respectively, at “normal” speed (1–2 seconds per con and ecc contractions).
  • The sedentary control group (C) which did not work out at all.
  To allow for a similar number of reps in the TS and SS group, the intensity (=weight used) in the SS group was reduced to the same 40–60% of the 1RM that was also used in the TE group. The TS group, on the other hand trained at 80–85% 1RM.

What do the changes in fiber type satellite cell increases actually tell us? Unfortunately, the answer to this question is by no means straight forward. In conjunction with the overall increase in domain sizes, cross sectional fiber size and myonuclear domain numbers (see Figure 1) the increased satellite cell recruitement in the traditional training group does yet support its superiority over super-slow training (learn more about satellite cells).

• I know that this is not ideal, but there's no way you do 6-10 reps with a time-under-tension (TUT) of 10-0-4 with the same weight you'd do 6-10 reps at a normal TUT of 1-0-1 or 2-0-2, accordingly, the results the scientists' analysis of the pretraining and posttraining muscle biopsies the authors analyzed for fiber cross-sectional area, fiber type, SC content, myonuclear number, and MND still have practical relevance.
  

  

  Figure 1: Percentage change (%) in mean fiber cross-sectional area, myonuclear domain size (domain), and number of myonuclei per fiber cross-section (myonuclear number) from pretraining to posttraining for each group (TS, SS, TE, and C). *Significant increase after training, p , 0.001. §Significant increase after training, p # 0.05. #Significantly greater increase after training compared with all other groups (SS, TE, C), p , 0.01. TS = traditional strength (Herman-Montemayor. 2015).

  And what does the scientists' analysis tell us? Well, along with the data in Figure 1, the exclusive increase in satellite cell content of type I, IIA, fibers (IIX and IIAX increased in both SS and TS, but not TE or control) that was observed in the traditional strength (TS) training group appears to confirm the superiority of this way of training when it comes to lying the foundations of further myonuclear domain growth (learn more in the "Muscle Hypertrophy 101").
  
  The fact that myonuclear domain increases of type I, IIAX, and IIX fibers occurred exclusively in the TS, yet not in the SS group, where only the domains of the type IIA fibers increased, does still appear to confirm the common prejudice that - for the average trainee - training at higher times under tension (TUTs) does not offer benefits that suggest faster or more robust size gains. Compared to strength-endurance training, however, super-slow training is still the better option. On a "per load basis" it is thus more effective to do fewer reps slower vs. more reps at a normal speed if your goal is to "grow" muscle.
• Vitamin D affects muscle recovery directly (Owen. 2015) -- We already know that vitamin D figures in one way or another in (a) the adaptive response to exercise and (b) the recovery process after strenuous workouts. Unfortunately our "knowledge" is based mostly on correlations and associations and can thus hardly be considered reliable evidence. That's something researchers from the Liverpool John Moores University, the Charité in Berlin, the Norwich Medical School and other European labs weren't happy with, either. Accordingly, they designed a randomised, placebo-controlled trial that involved twenty males with low serum 25[OH]D (45 ± 25 nmol.L-1) who performed 20×10 damaging eccentric contractions of the knee extensors with peak torque measured over the following 7 days of recovery prior to and following 6-weeks of supplemental Vitamin D3 (4,000 IU.day-1) or placebo (50 mg cellulose).
  
  To complement the results of this human trial, the authors conducted a parallel experimentation using isolated human skeletal muscle derived myoblast cells from biopsies of 14 males with insufficient serum 25[OH]D (37 ± 11 nmol.L-1) that were subjected to mechanical wound injury. Thus, the scientists tried to emulate the process of muscle repair, regeneration and hypertrophy in the presence and absence of 10 nmol or 100 nmol 1α,25[OH]2D3 in the petri dish.
  

  

  Figure 2: In view of the fact that the scientists used active vitamin D3 (calcitriol) in the in-vitro study, the improved recovery in the human trial is all the more the more relevant results of the study. It does yet pose the question whether similar or any effects had been observed in subjects with sufficient vitamin D levels in whom the provision of extra vitamin D3 may have increased 25OHD, but not the systemic calcitriol levels of which the scientists' in-vitro dta shows that it is responsible for the effects (Owens. 2015).

  What the results of both studies have in common is that they support the previously claimed role of vitamin D in muscle repair and regeneration. How's that? Well, the supplemental Vitamin D3 the D-ficient human subjects received didn't just increase the serum 25[OH]D levels. It also lead to measurable improvements of the recovery of peak torque at 48 hours and 7 days post-exercise. In conjunction with the observation that 10 nmol 1α,25[OH]2D3 aka calcitriol (=active vitamin D3, not the supplement you consume) improved muscle cell migration dynamics and resulted in improved myotube fusion/differentiation at the biochemical, morphological and molecular level in the cell study, where it also increased the myotube hypertrophy at 7 and 10 days post-damage, these preliminary data do just as the scientists say "characterise a role for Vitamin D in human skeletal muscle regeneration and suggest that maintaining serum 25[OH]D may be beneficial for enhancing reparative processes and potentially for facilitating subsequent hypertrophy" (Owens. 2015).

"Explosive Reps May Pay Off - At Least on the Bench: Fast Reps = Higher Muscle Activity, Higher Volume... Gains?" Find the answer to this question from a previous SuppVersity article here.

So what? Yes and no! Those are the answers to the questions you are probably about to ask. Yes, it does make sense to keep an eye on your vitamin D (25OHD in serum) levels, to do blood tests regularly and to supplement according to your personal needs. Yes, it does also make sense to get 1,000 IU of vitamin D3 per day even if you don't know you're deficient. And yes, all that may actually help you to recover faster.

What neither vitamin D3 nor super-slow training will do, though, is to turn you into a ripped super-muscular freak. In fact, the answer to the rarely asked question whether it makes sense to switch from a regular hypertrophy training regimen with a TUT of 1-0-1 or 2-0-2 to a super-slow regiment, is "no". Or more precisely: No, it is not generally recommendable to do super-slow training instead of regular resistance training if your goal is max. muscle hypertrophy.

A question the study by Herman-Montemayor cannot answer, however, is whether doing super-slow training only least temporarily (as part of a perdiodization scheme, for example) would help pro-athletes to make further or faster progress. Even without a study, though, it can be said that someone who has been training with a TUT of 1-0-1 and weights corresponding to his/her 6-10RM (=80-85% of 1RM) for years and for whom the super-slow training would constitute a novel training stimulus is probably more likely to benefit from intermediate super-slow training than the subjects in the study at hand for whom this was the first 6-week gym experience | Comment on Facebook!

References:

• Herman-Montemayor, Jennifer R., et al. "Early-phase satellite cell and myonuclear domain adaptations to slow-speed versus traditional resistance training programs." Journal of strength and conditioning research/National Strength & Conditioning Association (2015).
• Owens, Daniel J., et al. "A Systems Based Investigation into Vitamin D and Skeletal Muscle Repair, Regeneration and Hypertrophy." American Journal of Physiology-Endocrinology and Metabolism (2015): ajpendo-00375.