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Could neuromuscular electrical
stimulation make you lightning
quick? Researchers say: maybe
92 I I FEBRUARY 2017
PERFORMANCE
Arecent New Scientistfeature focused on
electrical-stimulation techniques used
to treat disorders such as depression
and anxiety. This clinical procedure of days gone
by, portrayed so starkly in One Flew Over the
Cuckoo’s Nest, is being resurrected in the rapidly
evolving field of neuroscience. And if it can be
shown to work for the brain (which, though an
organ, acts like a muscle – in other words, it can
be trained to improve), it could also boost the
credibility of neuromuscular electrostimulation
systems that claim to improve sporting
performance. A recent paper in the journal,
Frontiers in Physiology looked at the evidence.
A team of researchers led by Professor Menno
Veldman of the Centre for Human Movement
Sciences in the Netherlands waded through
years of research and journals, and came to two
key conclusions. First, neuromuscular electrical
stimulation (NMES) increases muscular strength
by increasing muscular tension, and second,
IMAGES
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Journal:Frontiers in Physiology, published 16 November 2016
together with increased oxidative capacity
and capillarisation of the stimulated muscles,”
the researchers stated, highlighting that these
are key attributes of a highly endurance-
trained individual.
Still, the technique’s physiological impact on
boosting strength and endurance at the same
time is disputed; further research should be
encouraged, say the authors, to prove whether
or not such training delivers benefits.
The authors also examined the impact of
low-frequency NMES on muscle and functional
endurance. Though noting the scarcity of
research in this area, they discovered three
studies that pointed to improved work capacity
and oxygen consumption at the anaerobic
threshold – both positive traits in triathlon.
Is this relevant to the active triathlete, you
might ask? Yes, respond the researchers. Not
only is NMES useful when recovering from
injury if weight-bearing exercise is curtailed, it’s
also of benefit when time is short and you want
a brief ‘sedentary’ workout.
TAKEAWAY TIPS
Q High-frequency NMES training is purportedly
beneficial for strength, with a frequency up to
50Hz applied intermittently.
Q Low-frequency NMES (10Hz and under) could
boost endurance. Apply continuously rather
than in intervals.
Q New to NMES? Start at a low frequency. In
rare cases, users have reported nausea.
Q Research shows that ‘less-fit’ individuals
benefit more from NMES training than unfit ones.
A recent paper suggests that electrostimulation training
results in endurance and muscular adaptations…
ELECTRIC
PERFORMANCE
RESEARCH
JamesWitts presents the key findings from the latest training, technology
and nutrition journals that you can apply to improve your own performance
SPORTSCIENCE
UNCOVERED
though evidence remains equivocal, NMES
also elevates endurance performance.
So what mechanisms are at play? It seems
the neurological process that increases
strength involves electrical stimulation (from
devices such as those produced by Compex)
depolarising the motor neurons of the nervous
system. High-frequency electrical pulses
(around 50Hz) from electrodes planted on the
skin, for instance, triggers muscle contraction
up to 60% of maximum.
However, several studies suggested that
high-frequency NMES training has a negligible
effect on endurance performance – a
conclusion disputed by the new paper’s
authors. Why? First, they argued, a session of
high-frequency NMES induces an exaggerated
metabolic and cardiovascular stress, primarily
due to increased motor-unit recruitment.
“Secondly, high-frequency NMES results in
a fast-to-slow shift in fibre type distribution
STRENGTH AND ENDURANCE
Graph shows how active individuals (light grey) enjoy a
greater improvement in endurance after low-frequency
NMES than after high-frequency NMES. For sedentary
individuals (dark grey), the opposite effect was seen.
Functional endurance improvement (%)
High-frequencyNMES Low-frequencyNMES
n=4
4%
n=8
35%
n=3
15%
n=23
12%
0
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