|NEMS ➾ Leg raises no more?|
I mean, a 9% increased muscle in 6 weeks in subjects who train regularly (some of them play soccer which happens to be a nice calf builder, too) - that's interesting, isn't it?
When the subjects had been randomly assigned to either one of the two treatment or the control group, the calf muscles of both legs were stimulated by the means of neuromuscular electrical stimulation (NMES), in an alternating fashion. A coin was tossed to determine which leg was assigned to the
- CP, where the stimulation was strong enough to trigger cramping or
- nCP, where the muscle was stimulated, but not hard enough to cramp.
"The applied stimulation protocol consisted of two stimulation sessions per week. During the calf muscle stimulation, subjects were seated on an elevated platform with hip and knee joints flexed at ~90° and both legs hanging down freely. Following a warm-up, consisting of three sets of five voluntary calf raises, calf muscles (Mm. gastrocnemii) of both legs were stimulated alternately using a portable battery-powered stimulator (Compex 3, Compex, Ecublens, Switzerland). The stimulation protocol comprised three sets of biphasic rectangular-wave pulsed currents at 30 Hz above the individual cramp threshold frequency (CTF; see measurements), an impulse width of 150 μs per leg. The 30 Hz was added to the CTF as it has been previously reported that cramps do not occur soon after a first cramp episode, which may be a function of cramp induced CTF increments. [...] According to the literature and pre-studies from our work group (unpublished), cramps are induced almost solely in shortened muscles (Bertolasi. 1993). Therefore, a custom-built ankle brace that fixates the foot in a neutral position (0° plantarflexion) was used to avoid the development of muscle cramps within the nCP. By contrast, plantar flexion was unhindered in the CP to elicit EIMCs" (Behringer. 2015).Each set consisted of 6 x 5 s contractions, intermitted by a 10 s break - resulting in a duty cycle of 0.33. Each set was followed by a 90 s pause. During this pause, the opposing leg was stimulated using the same stimulation protocol. Electrical stimulation was delivered to the medial (MG) and lateral (LG) head of the m. gastrocnemius.
You do know that...? (a) you are not going to see gains if you cramp for other reasons; (b) these other reasons can be mineral deficiencies, but magnesium is actually very rarely the culprit (sodium and calcium deficiencies are more likely to cause cramping especially in people who exercise); (c) having the occasional cramp is normal, but frequent cramping can be a sign for several diseases like liver failure, diabetes, etc - if you are cramping frequently, talk to your doctor and try to find out what it is that makes you so susceptible to cramps.And the results were impressive - in both the NEMS w/out cramping (nCP) and the NEMS with cramping (CP) groups, the scientist observed significant increases in muscle size (Figure 1).
|Figure 1: Changes in maximal voluntary contractile force at 0% and 30% plantar flexion and muscle cross-sectional are (mCSA) in subjects in the cramping (CP), non-cramping (nCP) and control (CG) groups (Berlinger. 2015).|
- Behringer, M., et al. "Electrically induced muscle cramps induce hypertrophy of calf muscles in healthy adults." Journal of musculoskeletal & neuronal interactions 15.2 (2015): 227-236.
- Bertolasi, L., et al. "The influence of muscular lengthening on cramps." Annals of neurology 33.2 (1993): 176-180.
- Kitai, T. A., and D. G. Sale. "Specificity of joint angle in isometric training." European journal of applied physiology and occupational physiology 58.7 (1989): 744-748.
- Thepaut-Mathieu, C., J. Van Hoecke, and B. Maton. "Myoelectrical and mechanical changes linked to length specificity during isometric training." Journal of Applied Physiology 64.4 (1988): 1500-1505.