Physical Education - The principle of individual differences
The principle of individual differences
Last but not least on the list of training principles is the principle of
We all start somewhere ... different.
It is usually practical to describe physical characteristics based on some
_average_. On average, Australian men are currently 5' 9" (1.75m) tall and
about 77kg. But walk down a busy street and you will see that there is
considerable variability! It should not be too surprising that there is
also a lot of variability in our internal characteristics.
Heart size, muscle mass, bone diameter, fibre type composition, position
of muscle attachments on bone, fat distribution pattern, joint flexibility,
etc., all vary from individual to individual. Two examples: On average, a
25-year-old untrained man will have a maximal oxygen consumption  of 45
ml/min/kg. However, there are completely untrained people who have walked
into a lab, gotten on a treadmill and had a VO2 max. of 70 ml/min/kg. I
tested a girl exactly like this myself once. I was teaching a class of Year
12 Physical Education students, and everyone was completing the 20m beep
test for aerobic capacity . I predicted her max. for the class based on
her exercise history (little, and she smoked!). Imagine my surprise when
she got to level 11 on the test (I predicted VO2 around 48 ml/min/kg). And
this girl had never done any real exercise!
There are equally "healthy" untrained young women whose max. is only 27
ml/min/kg. That is nearly a 100% difference in aerobic capacity before they
do the first workout! This is a physiological gap that will not be closed,
no matter how hard the "less endowed" classmates train. If the high VO2
girl were to train very hard, she might reach 60-65 ml/kg/min, a 15%
increase. The low VO2 girls can train equally hard and possibly reach 40
ml/kg/min, a larger 50% increase. The gap can narrow, but it will not go
away. Genetics place limitations on our body.
Example number two: On average, the fibre type distribution in the thigh
muscles is roughly 50% slow and 50% fast fibres. However, in a study by
Simoneau et al, 1989, muscle biopsies from the vastus lateralis (outside
thigh) of 418 males and females revealed a range of from 15% slow fibres to
85% slow fibres in different people. Coefficients of variation approached
30%. Again we see that there is considerable genetic variation in a
variable that has significant impact on performance. So, we each have to
focus on approaching the outer boundaries of OUR OWN physical potential.
Previous | Next