Shock Your Calves to Grow Stronger & Recover Faster: $650 Electromyostimulation Device Works, But Is It Worth It?

You will have heard about "calf shocker" routines, but would you have imagined that it takes electro shocks?

I don't know how often I've been writing about the truth and fallacy of the good old saying "no pain, no gain", here at the SuppVersity. And while it certainly has its merit for the faint-hearted, the notion that "pain" will entail "gain" is fallacious, also because it suggests that allowing for adequate recovery would be inferior to digging a deep black "hole of pain" (suggested read: "The SuppVersity Athlete's Triad Series").

And while I know that you know that this ain't the way to go, I am also honest enough to admit that I often catch myself pondering the incorporation of intensity techniques, additional exercises or some fat burning minutes of HIIT, but rarely thinks about the undeniable benefits of things like the hot baths for pre-regeneration and other means to speed up recovery (learn more) ...

Recovery, ceratinly not the #1 topic for gym-conversations

I am not sure, whether or not today's SuppVersity article on the surprising benefits of electrical muscle stimulation (EMS) during the recovery period is going to change that, but it certainly adds another interesting option to my toolbox. After all, the improvements in strength and the researchers from the Quincy College the University of Texas at San Antonio, the Hospital  of the University of Pennsylvania, the National Strength and Conditioning Association and the University of Florida present in their most recent paper in the April issue of Official Research Journal of the American Society of Exercise Physiologists would suggest that it will not just allow me to return to the gym earlier, but will also make me stronger.

The "Marc Pro(TM)" is not just the $650 device used in the study, it is also one of most frequently used words in the study at hand... what? No, there is no conflict of interest declared, but I believe the Journal of the American Society of Exercise Physiologists does not even require that.

The study of which I'd better tell you in advance that is has a slight smack of "product pimping", because it mentions the specific EMS device, the Marc Pro(TM) not just in the methods section, but also in the title (Westcott. 2013), involved two trials with comparably large groups (n=43 / n=62) of male and female subjects in their best years (mean age: 61.3 / 61.7 years).

10 weeks 2x per week full body + 4x per week EMS

Suggested read: "Fast Paced High-Resistant Explosive Circuit Training Burns More Fat and Builds More Muscle Than Classical Weight Training. Trainees Dropped 1.5% Body Fat and Gained 3 Pounds of Lean Mass in 8 Weeks." - Don't discard the value of a fast paced full body resistance training (read more).

During both 10-week trials all participants trained twice a week for 60 minutes. The training comprised a medium-paced circuit training on 13 Nautilus machines including leg extension, leg curl, leg press, hip abduction/adduction, chest press, seated row, shoulder press, lat pull down, low back extension, abdominal flexion, torso rotation, neck flexion/extension and calf press. Each exercise was performed only once and the weight was progressively increased by 1% whenever the subjects were able to perform more than the prescribed number of 8-12 reps at a well-controlled pace of 3s for both the concentric and eccentric portion of the exercise. In addition to the standard strength workout, the subjects performed ~20 min of recumbent cycling at 70 to 80% of predicted maximum heart rate) and ~5 min of major muscle group stretching exercises towards the end of each workout. 

While all subjects underwent the same supervised workout program, only 50% of them were assigned to the EMS group, and instructed to self-administer 1h of electrical muscle stimulation to the calf muscles of both legs four times a week. With the two obligatory exercise sessions, this allowed for two "recovery sessions" in-between workouts.

Figure 1: Changes (rel. to baseline) in the EMS and control groups after 10-weeks of training (Westcott. 2013)

As the data from the pre- and post strength 3-RM tests and the results of the fatigue questionnaire, a 9-point rating scale with anchors of 1 (never experience feelings of calf muscle fatigue) and 9 (always experience feelings of calf muscle fatigue) in figure 1 goes to show you this routine was surprisingly effective in both increasing the effective gains in calf muscle strength and decreasing the workout induced fatigue.

So what's the mechanism here?

It is not exactly likely that the medium intensity EMS targets the IGF-1 + muscle growth promoting PGC-1 a4 isoform (learn more)

The exact mechanism for the benefits, the researchers observed in both experiments, is not fully understood, they stand in line with previous research mostly by members of the same research group (Parker. 2003; Kemmler. 2010; Wescott. 2012; DiNubile. 2011; Girold. 2012) which suggests that the application of electical muscle stimulation "causes positive cellular responses such as nitric oxide (NO) production, fluid shifts, protein clearance, and angiogenesis" and allow for the hypothesis that additional, isokinetic contractive stimulus has the potential to induce mRNA transcriptional proteins such as PPAR gamma co-activator (PGC)-1 alpha (learn more) and the vascular endothelial growth factor VEGF.

Against that background, the scientists assumption that [...]the enhanced muscle recovery associated with [...] electrical stimulation may be due to increased microcirculation, muscle loading, and angiogenesis." (my emphasis in Westcott. 2013) appears reasonable and would warrant their conclusion that EMS which is hitherto used mainly by professional athletes (esp. football players) "may also be beneficial for less fit individuals who experience  prolonged periods of recovery or uncomfortable levels of muscle fatigue after exercising." (Westcott. 2013)

---

I openly admit: Hot baths are still not a part or my "pre-recovery" routine, but I like some cheap and effective walking on an incline on the day after a leg workout.

Bottom line: Depite the overall promosing results of the study at hand, I'd still have a few questions as far as (a) the usefulness, (b) the alternatives and (c) the superiority of EMS therapy as a means to accelerate recovery and adaptation actually is. A handful of studies, a shiny website and the argument that it does works in recreational, or as the scientists write "less fit" trainees, as well as in pro-athletes won't make me pay approx. $650 for an "electro shocker".  This is all the more true in view of the fact that regular aerobic exercise and HIIT (learn how to set up a routine) will also promote PGC1-alpha and VEGF and could - appropriately dosed - probably elicit similar effects.

Apropos "effects" you should not forget that the parameters the scientists measured are actually both performance parameters. Regardless of the fact that the latter is called "fatigue", the fatigue after a standardized workout is mainly determined by your central and peripheral conditioning. It is thus obvious that you should be able to reduce the post-workout fatigue by any means of additional exercise that does not overtax the system - this may also involve enhanced recovery, but the enhancement is a function of physiological adaptations and not externally applied electrical stimuli.

Against that background, the only advantage of EMS over "conscious", i.e. brain-controlled contractions such as a 3x3min (x2 for each leg) session of single-legged body-weight calf-raises or even a simple walk in the park with a deliberate emphasis on calf-involvement would produce, appears to be that it would ease the burden on the central nervous system. Whether that's essentially necessary for the average trainee is however questionable; and though I would probably be slightly irritated, if you called me "an average trainee", I for my part will stick to some recuperative walking on an incline to promote calf-recovery.

References:

• DiNubile N, Westcott W, Reinl G, et al. The Marc  Pro TM device is a novel paradigm shift in muscle conditioning, recovery and performance:  Induction of nitric oxide (NO) dependent enhanced microcirculation coupled with angiogenesis mechanisms. JEPonline. 2011;14(5): 10-19.
• Girold S, Jalab C, Bernard O, et al. Dry-land strength training vs. electrical stimulation in sprint swimming performance. J Strength Cond Res. 2012;26(2):497-505.
• Kemmler W, Schliffka R, Mayhew JL, von Stengel S.  Effects of whole-body electromyostimulation on resting metabolic rate, body composition, and maximum strength in postmenopausal women:  The training and electrostimulation  trial. J Strength Cond Res. 2010;24(7):1880-1887.
• Parker MG, Bennett MJ, Hieb MA, et al. Strength response in human femoris muscle during 2 neuromuscular electrical stimulation programs.  J Orthop Sports PhysTher. 2003:33(12): 719-726.
• Westcott WL, Chen T, Neric FB, et al.  The Marc Pro TM device improves muscle performance and recovery from concentric and eccentric exercise in duced muscle fatigue in humans: A pilot study.  JEPonline. 2011;14(2):55-67. 
• Westcott W, Han D, DiNubile N, Neric F, Loud RLR, Whitehead S, Blum K. Effects of Electrical Stimulation Using the Marc Pro(TM) Device during the Recovery Period on Calf Muscle Strength and Fatigue in Adult Fitness Participants. JEPOnline. April 2013; 16(2): 40-49.

Three is More Than One: Higher Volume Increases Strength Gains in Legs, and Satellite Cell Recruitment and Fiber Size in Legs & Traps. Plus: Data on Myostatin, IGF1, MGF & Co.

Image 1: The green dots that are crowding left and right from the blue myonucleus are the satellite cells (Hanssen. 2012)

In case you are not really sure what a "satellite cell" is and why you should care abouts it's "recruitment", you have probably missed the Intermittent Thoughts on Building Muscle series and should get into detention. Otherwise, here is the news: In a study that has been published in the latest issue of the Scandinavian Journal of Medicine in Sports Science T.S. Hanssen et al. published a paper with the auspicious title "The effect of strength training volume on satellite cells, myogenic regulatory factors, and growth factors" (Hanssen. 2012). Exactly that kind of study that would have the potential to take the mostly common or bro-sensical reasoning behind the current recommendations on training volume to the next, a scientific level, if it the scientists would finally realize that strength training noobs are hardly a better model for advanced trainees than rodents :o(

Full body training 3x /week: How many sets are optimal?

For their study, Hanssen et al. recruited twenty two healthy untrained men (age 26.5y; height: 181.8cm; weight: 81kg) and assigned them to one out of two full-body workouts, with identical exercises (leg press, leg extension, leg curl, seated chest press, seated rowing, latissimus pull-down, biceps curl, and shoulder press), but different amounts of sets for a given body part:

• 3x Legs & 1x Upper Body: Trainees in this group performed 3 sets for each of the leg exercises and 1 set for the upper body exercises
   
• 1x Legs & 3x Upper Body: Trainees in this group performed 1 set for each of the leg exercises and 3 sets for each of the upper body exercises

All subjects started out with 10 reps per set in the first two week. In weeks 3-6, the intensity was increased to 8RM and in the last 5 weeks (7-11) all participants trained at their "7-rep max":

Participants were encouraged to continuously increase their RM loads during the intervention and they were allowed assistance on the last repetition.

In addition to the three strength training sessions per week, the participants were allowed to perform one (not more!) additional steady-state cardio session. And while this may help with standardization, my mathematical skills tell me that the 3L-1UB group performed only 14 sets per workout, while the 1L-3UB group performed 18 sets, simply because the number of lower and upper body exercises was not identical. Now, everyone who does not claim that he or she does not need to train legs (for whatever stupid reason) will know leg training is much more draining than upper body workouts, so "intensity-wise" the workouts were probably still identical.

Single vs. multiple-set training? Nothing new or exciting if it was not for the specific data

We have seen similar studies before - most of them with the same, very unfortunate limitation of being performed on strength training novices, by the way - and the results of this study would hardly be exciting, if it were not for the sheer amount of data Hansson et al. recorded:

Image 2: If those acronyms don't ring a bell, click here to learn more.

• muscle strength and muscle fiber size,
  
  
• the number of satellite cells and number of satellite cells positive for myogenin and MyoD,
   
• the number of myonuclei, myogenin and MyoD content of muscle samples, and
  
  
• myostatin and a whole host of growth factors, namely IGF-1, MGF, HGF, FGF2 and VEGF

This is what I call a "comprehensive" analysis ;-) And one which brought about some pretty interesting results, of which the increases in muscle strength and fiber size are unquestionably the most straight-forward and least surprising ones (cf. figure 1):

Figure 1: Changes in 1RM strength and fiber area after 11 weeks on the training regimen with different set schemes (data calculated based on Hanssen. 2012)

As you can see in figure 1 strength-wise, only the leg (m. vastus lateralis), yet not the back (trapezius) muscle benefited from the increased training volume. When you do take a look at the fiber size, however, it becomes obvious that as long as we compare 1 vs. 3 sets more is actually more +24%, to be precise (the 4% difference for the fiber size in the legs is statistically non-significant).

Figure 2: Relative changes in myonuclei number per muscle fiber and the number of satellite cells after 2 and 11 (post) weeks of the training intervention (data calculated based on Hanssen. 2012)

If you also take into account that the data in figure 2 clearly shows that an increase in training volume leads to increased satellite cell recruitment (indicated by the increases in the number of myonuclei per muscle fiber) and number, it becomes obvious that you are missing out on the growth promoting effects of strength training. The decrease in myonuclei per muscle fiber in the latter 9 weeks of the training intervention in the low volume upper body group (dark red bars in figure 2) would also suggest that this is particularly true for the experience strength trainee in whom the initial 2-week growth spurt of which Hansson et al. state that it was one of their two "main observations":

The novel finding in our study was the early increase in the proportion of activated satellite cells, the early increase in total number of satellite cells and the dependence on training volume in the leg muscle. The number of activated satellite cells, indicated by myoD and myogenin expression, increased from ~2% before training to 6–10% 2 weeks into the intervention.

So as "novel" as this finding may be, it is still somewhat unsatisfying for experienced strength trainees, who will have to rely on the hypothesis that their response will be an ameliorated version of the "late" growth response in the study at hand, which would support my personal observation that 3x3 i.e. three exercises à three sets per body part is at the lower end of the "optimal" volume continuum for advanced trainees. A volume continuum, by the way, that is capped at 12-15 sets for the largest body parst, i.e. legs and back and does by no means extent into the "insanity realm", where people perform 20 sets for biceps and 20 working  sets for triceps on a 5-day body-part split.

Surprise: No statistical significant differences in growth factors

What I found quite surprising though, is that this advantage of 3- vs. 1-set training was not reflected by greater increases in myostatin and/or MGF (want to know more about MGF, click here for the pertinent installment of the Intermittent Thoughts). MGF was even higher in the vastus of the 1 set group and the smaller incline in myostatin levels in the 3-set group (1.1x vs. 1.8x) did not reach statistical significance.

Figure 3: Changes in mRNA levels of myostatin, IGF-1, MGF, HGF, FGF2, and VEGF in the 10 subjects with the largest satellite cell response (seven from 3L-1UB and three from 1L-3UB; data adapted from Hanssen. 2012)

If we do yet take a look at the changes in mRNA levels of myostatin, IGF-1, MGF, HGF (hepatocyte growth factor; growth factor for satellite cells, cf. Sheehan. 2000), FGF2 (fibroblast growth factor; promotes cell adhesion and proliferation, as well as the build up of callege, cf. Yun. 2012) and VEGF (cf. figure 3) in the 10 subjects with the largest satellite cell response (seven from 3L-1UB and three from 1L-3UB), we do see that all but myostatin and VEGF were statistically significantly elevated above baseline. These results stand in line with the main message of the Intermittent Thoughts which was that it is the interaction of a whole host of "hormones" (and peptides) that "builds muscle" - and not as the producers of a certain category of 100% useless "all-natural" supplements want to make you believe, testosterone (or any other growth factor) alone.

And while it was to be expected that the expression of those growth factors would decline over the course of the 11-week intervention period, I am honestly wondering, whether the decrease in reps from 10 (initial two weeks) to 8 and subsequently 7 reps per set had anything to do with it... but I guess, this is an issue for the next study, about which, you will read nowhere else than right here, at the SuppVersity, the place where bro- and pro-science unite in the spirit of true wisdom - but I guess you know that by now, don't you? ;-)

+25% Increased Quadriceps Weight and Profound Increases in Vascularization in Rodents From Real NO Donor! Study Shows: Nitric Oxide Works, At Least in Old Mice

Image 1: This is what NO boosters
promise, yet mostly don't deliver.

Many people believe that there is some truth to every myth. And in fact, a recently published study rom the Department of Surgery, Biological Sciences and Human Anatomy & Cell Science (quite a mouthful) at the University of Manitoba in Winnipeg, Canada, shows that even there may be a quantum of truth even in the "arginine" or "nitric oxide" or "pre-workout" or "however else you may want to call it" myth, which says that getting a decent pump will help you build muscle (Leiter. 2012). Now, aside from the fact that the latest generation of those pre-workout supplements boasts of having no arginine in them and relies solely on the stimulant rush the various *amines in them will produce, there is not a single study in which supplementation with X, Y, or Z amount of l-arginine (or other forms of the alpha-amino acid) had produced greater increases in skeletal muscle hypertrophy than an iso-nitrious (equal amount of nitrogen) placebo.

If arginine does not work, this does not mean that NO does not work either!

Those of you who have listened to my dissertation on amino acids, in the Amino Acids For Super Humans series on Carl Lanore's Super Human Radio, will yet probably remember that I mentioned a couple of test-tube studies, in which the incubation of intact myotubes with high amounts of l-arginine induced a profound growth response. Moreover, slightly more recent evidence from the Center of Exercise Science at the University of Florida points to the involvement of nitric oxide in the release of PGC-alpha, about the far-reaching metabolic effects (increase in mitochondrial density, effectivity and via irisin "browning of the fat cells", cf. PGC-alpha, irisin) you have read several times, already, here at the SuppVersity - and, as of late, probably even heard of in mainstream media.

Image 2: MP Assault is currently #2 in the Top 50 Best Selling Products over at BB.com,  it is yet only 1/3 purported NO-boosters in the Top 10

That those in-vitro results did not yet translate into real-world gains among the millions of consumers who have bought truckloads of NO XPlodes and SuperPumps over the past couple of years, is simple: While our bodies are capable of producing nitric oxide from arginine, simply taking in more than you need, won't increase your total and even less the nitric oxide level in your skeletal muscle tissue to a degree that would have physiological effects beyond "feeling pumped" (and I guess most of you will have noticed that especially on low carbohydrate diets, even this cosmetic effect is oftentimes absent when you consume one of the so called "NO boosters").

Isosorbide dinitrate, a real NO booster

In their study, Jeff R.S. Leiter and his colleagues did not even bother with l-arginine, but chose a pharmacological NO donor, which is usually prescribed to patients suffering from angina pectoris: Isorsorbide dinitrate, a long acting form of nitrates that is sold under the brand names Isordil, Cedocard, Sorbitrate, etc. To evaluate whether the administration of this medication could help combating the age-induced decline in satellite cell activation and subsequent loss of skeletal muscle mass, the scientists treated 18-months old female C57BL/6 mice (in human terms those mice were grannies) with either 66mg/kg isosorbide dinitrate (human equivalent: 5mg/kg) or placebo for 6 weeks. In addition to the "supplementation", half of the mice had free access to one of those tiny wheels, of which mice - contrary to the lazy human beings for whom they are used as a model - usually avail themselves voluntarily. Altogether, this leaves us with 4 groups:

1. Control group: no wheel running, no NO donor
2. Exercise group: access to wheel, no NO donor
3. Treatment group: no access to wheel, 66mg/kg isosorbide dinitrate
4. T + EX: access to wheel, 66mg/kg isosorbide dinitrate

As you can see in figure 1 the "gains" the old mice made, were far from being earth-shattering, but in view of the fact that they only ran whenever they wanted to (unfortunately there is not data on the exact time the rodents spent on the wheel) an increase in quadriceps weight of +25% over the control group and still +8% over the "exercise-only" group is certainly worth mentioning.

Figure 1: Muscle weight of skeletal muscle of exercised and/or isosorbide dinitrate treated 18-months old mice after 6-weeks (data adapted from Leiter. 2012)

That being said, the increases in muscle DNA synthesis and the VEGF (vascular endothelial growth factor) induced increase in vascular density are probably way more remarkable than the non-negligible increase in muscle weight, anyways.

Figure 2: DNA synthesis and vascular density in skeletal muscle of exercised and/or isosorbide dinitrate treated 18-months old mice after 6-weeks (data adapted from Leiter. 2012)

After all, the angiogenic effects of VEGF and the subsequent permanent (not cosmetic ;-) improvements in capilarization do not only facilitate an improved nutrient delivery to the muscle, the expansion of the "nutrient supply grid" is also a necessary prerequisite for future muscle growth.

Would the combination of an effective NO donor with leucine/HMB work even better?

What is yet interesting, though is that in those "old ladies" the exercise induced skeletal muscle protein synthesis obviously could not keep pace with the increase in DNA expression.

Figure 3: Mean fiber diameter and protein synthesis in skeletal muscle of exercised and/or isosorbide dinitrate treated 18-months old mice after 6-weeks (data adapted from Leiter. 2012)

The decrease in DNA/protein ratio, as well as the non-significant increase in fiber diameter (cf. figure 3) certainly raise the question, whether the additional provision of a significant amount of leucine or - in view of previous promising results in elderly populations - HMB would not result in significantly more pronounced gains in skeletal muscle mass. After all, it seems that the incorporation of protein into the hypertrophying skeletal muscle has been the rate-limiting factor in the study at hand.

Image 3: For patients with angina pectoris,
these small sublingual tablets are life-saving,
for the average physical culturist, they
pose a non-negligible health risk.

It is yet still probably not a good, let alone a healthy idea, to get yourself isosorbide dinitrate (IS) from the various online and offline gray-markets, regardless of whether or not you believe your protein synthesis can keep pace... ah, I almost forgot to mention: Those of you who pop some of those little blue pills on a daily basis - you know, those which help you "perform" - probably won't need the IS, anyways. After all, the results of a 2005 study by Hinkle et al. would suggest that Viagra (and similar phosphodiesterase inhibitors) could exert similar effects (Hinkle. 2005) - whether this is a "healthier" alternative is yet still questionable.