Research Review
Fitness gains: Self vs PT-trained
Title: Effect of Supervised, Periodized Exercise Training versus Self-Directed Training
Author: Dr’s Storer et.al (University of California Los Angeles, USA)
Source: Journal of Strength & Conditioning Research, pre-publication, 2014
Introduction: University is back in full
swing, which means I have a new cohort
of enthusiastic students studying to be
doctors, exercise and sports scientists,
researchers, physiotherapists and
researchers. The stress placed upon
students to excel is well established,
however many individuals forget that
the professors are also stressed – from
time-to-time at least… I recommend
to all of my students that they have a
good balance of study and personal
wellbeing, whether that be achieved
via surfing, swimming, yoga or weight
training – just so long as the stresses
are kept in balance. One can’t be
hypocritical, so I practice what I preach
and either surf or hit the gym every day
during the week to maintain that all-
important balance.
When training I can’t help but listen
to the ‘guidance’ being provided
around me, quite often by unqualified
individuals who are, to be polite, less
than accurate. Yet, quite a number are
hesitant, for any number of reasons,
to procure the services of a personal
trainer to help them achieve their goals.
Ultimately, individuals want to be
confident that time and money spent
on a personal trainer will be worth
the investment. This new research
conducted by Dr Storer and his
colleagues supports the notion that it
is. Although there are literally thousands
of research findings on the effects
of aerobic exercise and progressive
resistance training, surprisingly, a review
of the literature identified a scarcity of
support for personal trainers.
Method: As this was a traditional
research project, 34 individuals (healthy
males, 30 to 44 years of age with three
months of exercise experience) who
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NETWORK AUTUMN 2014 / WWW.FITNESSNETWORK.COM.AU
were members of a commercial health
and fitness facility volunteered to
participate in the study. They were
randomised into two groups, one of
which was to complete 12 weeks of
periodised exercise training under the
guidance of qualified personal trainers
(TRAINED) and the other of which was
to complete 12 weeks of periodised
exercise training without any guidance
(SELF). The researchers were interested
in gains in lean body mass (measured
by dual energy x-ray absorptiometry
(DXA)), muscular strength (1-RM),
muscular power (vertical jump height),
and aerobic capacity (i.e. VO 2 max
assessed using a treadmill). To further
support the integrity of the findings by
eliminating any potential ‘testing bias’,
the study used ‘blinded investigators’,
meaning the researchers that did the
pre- and post-testing were not aware of
which group the participants were in.
Results:
Not
surprisingly,
nine
subjects withdrew from the study
at various points (5 from TRAINED, 4
from SELF) due to either moving out
of the area or inability to meet the
training commitments. The training
volume completed by the TRAINED
group averaged 150 minutes during
their planned session. Subjects in the
SELF group completed 172 minutes of
exercise per week, with the majority of
their training spent in resistance training
(39 per cent) followed by jogging
(27 per cent) and ‘other activities’ (29
per cent). Both groups had very high
compliance to the three day per week
training requirement. Over and above
this, the TRAINING group completed
an additional 1.8 days per week of
further training, while the SELF group
completed 1.3 extra days per week over
the 12-week training period.
With regard to lean body mass, the
TRAINED participants gained an
average of 1.3kg in lean muscle mass
over the 12 week period, whereas
the SELF group demonstrated a
0.0kg increase in lean muscle mass,
which represents quite a significant
difference between the two groups.
Additionally, the TRAINED group
improved their percentage body fat by
approximately 2.0 per cent over the 12
weeks compared to only 1.0 per cent
improvement in the SELF group.
With regard to muscular strength, the
TRAINED group significantly increased
both their chest press strength and
leg press strength by 42 per cent and
35 per cent, respectively. The SELF
group, however, increased their chest
press strength and leg press strength
by only 19 per cent and 23 per cent
respectively. The estimated peak
and average leg muscle power was
increased significantly in the TRAINED
group by 6 per cent and 10 per cent,
whereas the SELF group only increased
by 0.6 per cent and 0.1 per cent, which
represents quite a dramatic difference
in improvement between the two
groups. With regard to maximal aerobic
capacity, the TRAINED group increased
their relative VO 2 max (ml/kg/min)
significantly by 7 per cent. Conversely,
the SELF group only increased their VO 2
max by 0.8 per cent.
The authors concluded that this was the
first study to describe the effectiveness
of supervised, periodised training in a
commercial health and fitness facility.
Pros: This is an excellent study which
lends empirical evidence/support to the
benefits associated with using personal
trainers. It is interesting that the self-
training group completed approximately