Monday, April 15, 2013

Shock Your Calves to Grow Stronger & Recover Faster: $650 EMS Device Works. Is it Really Worth the Money?

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.

  • 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.