Looking back over the evolution of the human body tells us a
lot of the function of our muscles. Look at the difference in genetics, and the
muscle fibre percentages people have from different parts of the world. This I guess
is how we come across genetic freaks, who are simply an exaggeration of their
race. For the average people among us, when we look at the body itself and the
different muscle groups within it doesn’t it make sense to train them
differently? In a way which their natural environment has forced them adapt to?
Let me explain in more detail.
For argument’s sake let’s say that on average a male in his
early 20s would have around 40% slow twitch muscle fibres and 60% fast twitch
muscle fibres. This doesn’t mean to say every body part within his body is
equally split which surely means that certain muscle groups would respond better
to higher repetition training as where others would respond best to powerful
As a gross generalisation the deltoids, back muscles and
thighs are generally higher in slow twitch muscle fibres. When you consider
that shoulders do tend to respond best to high repetition, blood volumisation
training as do thighs and even back it makes sense! In contrast, the
hamstrings, chest and arms are normally slightly higher in fast twitch muscle fibres.
This doesn’t mean lifting heavy with shoulders or doing high repetitions with
arms won’t work because it certainly still can! All it means is that you have a
new angle to approach your training from.
Personally, I will hit my shoulders and thighs with high
repetition for most of the time and the difference in development is very noticeable
for me. In contrast I have focussed on heavy pressing on chest day which is my
weakest muscle group and that has also responded well.
Please do not think I am dismissing genetics because the
truth is your genetics are going to be the biggest factor, but for the average
person with an average spread of muscle fibres this makes for a very
With all being said I am going to lay down a challenge for
you based on your individual body parts.
Thighs – aim for repetition ranges of 80-100 on leg extensions,
leg press and around 20-30 on squats.
Shoulders – use plenty of dumbbell raise variations with
repetition ranges of anywhere between 20-50, using drop sets and giant sets.
Back – employ giant sets with exercises which give a varying
range of movement for the back muscles using a combined repetition range of
150-200 across the giant set!
Biceps – try single arm preacher curls with maximum focus on
the eccentric contraction as well as the concentric portion with a repetition
range of 4-6 per arm.
Triceps – try close grip bench press with a repetition range
of 4-6 with very solid emphasis on the isometric contraction as well as the
eccentric contraction. During the concentric contraction try and apply as much
power as possible to help optimise muscle fibre recruitment.
Hamstrings – try seated leg curls with a repetition range of
5-8 with plenty of emphasis on powering through the concentric contraction and
fighting the weight during the eccentric contraction.
Using these principles over a 4-5 week period will soon show
you whether or not you are benefiting or not from this style of training. One thing
is for sure, in my opinion training each body part on its individual profile
works for me!