KELLY MARSHALL JUNE 2014:Layout 1 01/05/2014 15:44 Page 1
22 Nottingham Local Magazine
by Kelly Marshall
(Hons), BSc (Hons),Dip PT,
NASM, SFS, IFS, CES
www.thebodyproject.net
or email: [email protected]
KELLY
The general assumption that low intensity
exercise burns more fat than higher intensity
exercise still exists and is fuelled by the truth it
holds from a face-value perspective. If we
exercise at a lower intensity then YES we do
use a higher proportion of fat for fuel instead
of carbohydrate (in the form of glucose aka
sugar). HOWEVER….. Exercising at a higher
intensity and beyond the aerobic training zone
burns more total energy and fat! Example:
Person A
Exercises for 30mins
@ 60% max heart rate
Total calorie burn 200
calories: 60% fat 40% sugar
Total units: 120 of fat and
80 units of sugar
Person B
Exercises for 30mins @ 60% max heart rate but frequently puts little
spikes of 85% in for short periods
Total calorie burn 300 calories: 50% fat 50% sugar
Lactic Acid (our secret friend) – Exercise at sufficient intensities
elevates our innate stress hormones (adrenaline, nor-adrenaline and
cortisol), similar to our ‘fight or flight’ response and this is thought to
relate to anaerobic metabolism (the burning of sugar for fuel without
oxygen) and the build up of its waste product lactic acid. When Lactic
acid builds up to extreme levels it can stimulate testosterone and human
growth hormone (HGH) which act as described below resulting in a
leaner physiology!
Testosterone and Human growth hormone – When these
hormones are present at the same time as the stress hormone cortisol,
the three synergistically enhance fat burning as muscle breakdown is
blocked and fat storing at the belly area is reversed! Halleluiah!
Intelligent exercise is therefore that which is intense enough to elicit the
hormonal metabolic effect. But how? The format and exercises used in a
given workout can be dramatically different but the Key elements for
impacting your hormonal influence are the same, get the following in to
your workouts and you will be on the right track:
Breathlessness – This correlates with the ‘fight or flight’ response and
produces adrenaline, nor-adrenaline and IL-6 and supports a bigger
metabolic benefit post-exercise
Heavy – pushing yourself to lift heavier weights (with strict form)
supports the benefit of achieving muscle failure and increasing lactic acid
(and its accompanying muscle building friend, testosterone) and IL-15.
So Person B burns more calories and more fat units overall – clever exerciser!
Heat – is correlated with the release of adrenaline and the afterburn
calorie benefits to high intensity exercise. Like putting fuel in the fire…
.revving up your engine for fat burning.
As well as the influence of intensity on calorie burning, there is also a
significant power that comes from hormones and for simplicity (though it
is far from one-dimensional) I will outline the main points to appreciate.
Burning – Getting that ‘burning’ feeling in the muscles highlights the
required lactic acid build up that in turn correlates with IL-6 and HGH.
Total units 150 of fat and 150 units of sugar
The underlying effect of hormones…
Interleukin-6 (IL6) – is a signalling molecule released from working
muscles during exercise and essentially acts as an ‘energy sensor’ that
sends a command to fat tissues and other muscle cells to increase the
burning of fat. It also signals the liver to breakdown and use fat stores for
the production of more fuel (in the form of glucose) so intense activity
can be sustained (this process known as gluconeogensis). IL-6 is
generated on the mechanical movement of muscles but does not result
in muscle soreness. This is why total body approaches and exercises that
incorporate combinations of muscle groups are great options for
optimising this hormone.
Interleukin-15 (IL-15) – this clever muscle molecule is stimulated by a
specific type of training – explosive movements, lifting heavy weights and
when muscles achieve fatigue, targeting what we call type II muscle fibres!
The uniqueness of this hormone is that it promotes muscle growth while
enhancing fat loss at the same time!
Lifting hard and heavy doesn’t mean big muscles ladies, due to women
having a lower base level of testosterone and HGH than men. What
higher intensity exercise, incorporating the above factors does mean is
significant body composition change (fat : muscle ratio), body tone and
fitness.
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