The review showed that strength
training on a stable surface resulted in
29 per cent greater force output than
training on an unstable surface.
ms after foot contact with the ground. That’s to say, the speed at
which injuries occur is faster than the body’s ability to prevent them
occurring. Balance training cannot improve these times and prevent
these happening, regardless of how good your balance or stability is.
Balance training does appear to assist the elderly in reducing the
risk of falls, though Mansfield et al. (2015) note that the optimal dose
of this type of training is still unknown. However, there appears to
be value in doing a block of balance training with groups such as
the elderly and those with Parkinson’s, and then doing a booster of
this type of training after the initial period to maintain the initial gains
achieved. Rossi et al. (2013) reported that after six weeks, the gains
achieved from balance training was lost, hence the proposal that
booster sessions may be of tremendous value.
It appears that balance training, and the body’s need to be able to
adjust its position in response to a change in balance, is so specific
and complex that unless the activity being trained is an exact replica
of the environment required, very little improvement in performance
will carry over.
General balance tests, such as one leg stance, may also have little
value in determining a person’s overall skill in maintaining balance.
Certainly, if you choose to assess a person’s ability to balance using
the single leg test, you need to be aware that the activity you have
them do to improve this will affect the outcome. Simply put, if you
want someone to be better at single leg balance tasks, have them
practice single leg balancing.
As a trainer, this means identifying the activity the client wants
to improve their balance in and then training them in that specific
task. The evidence suggests that doing more complex tasks on an
unstable surface has no transfer unless your client wants to become
good at activities on that specific training device.
Key Point 2: Unstable surface training does not
provide systematic training-specific advantages
over a stable surface
In 2015, a systematic review and meta-analysis on elite
participants was published in Sports Medicine by Behm
et al. The review showed that strength training on
a stable surface resulted in 29 per cent greater
force output than training on an unstable
surface. It also pointed out that while the
challenges to postural stability may
be greater during training on an
unstable surface, the results of the review
demonstrate that this increased degree of
stress does not lead to improved balance.
The paper concluded that the lower force
and power outputs, as well as the decreased
movement velocity and range of motion
associated with unstable surface training,
may result in less rigorous strength and
power training adaptations.
Essentially, this means that if you wanted
to increase an elite individual’s strength, you
should get them to perform the exercise
on a stable surface. The Canadian Society
for Exercise Physiology supports this with
its position stand from 2010 in which it
states; ‘From a performance standpoint,
unstable devices should not be utilised when
hypertrophy, absolute strength, or power
is the primary training goal, because force
generation, power output, and movement
velocity are impaired and may be insufficient
to stimulate the desired adaptations,
especially in trained athletes.’
However, Behm and colleagues suggest
that in non-elite participants, unstable
surface training may have functional health
benefits. The 29 per cent reduction in force
output (force deficit) when training on an
unstable surface may actually be of benefit,
as the lower forces that the individual can
produce on an unstable surface might
decrease training-related injuries and be
of value in rehabilitative environments.
Children or novices might be target groups
for this type of training, as these populations
would be better suited to having their
neuromuscular patterns challenged, than
having a focus on training load.
The use of unstable platforms has also
shown an increase in muscle activation (EMG)
due to the stabilising function. Behm et al.
suggest this may also be of value in novices
because, as the muscle activation levels are
higher, the loads required to achieve this effect
are lower. Willardson et al. (2009), however,
showed that EMG activity in muscles used for
squats, deadlifts and overhead presses were
not that different, with muscle activation on
unstable surface being only 7 per cent higher
than on a stable surface.
In summary, the research suggests
that in most cases training on an unstable
surface provides less value than a stable
platform when aiming for the usual strength,
power and hypertrophy outcomes. However,
there may be some functional health gains
and safety-related benefits that should be
researched further before real values can be
assumed.
Dr Mark McKean PhD AEP CSCS is a sport and
exercise scientist and Level 3 Master Coach with
ASCA. He is Adjunct Senior Research Fellow at USC
and editor in chief for Journal of Fitness Research.
NETWORK SPRING 2016 | 57