By Coach Steve
It's the same old tired excuse you've heard so many times, "I'd
be really fast if it weren't for my non-athletic parents!" Or, "I
train as hard as anyone, but I'll never be as fast as so-and-so...just
bad genes I guess." Well, let's see what the sports scientists have
found in researching this complex issue.
Comparative genetic research for human athletic performance has
submitted sedentary monozygotic (identical) twins to identical exercise
regimes under controlled conditions over a predetermined period.
To make a long story short, researchers found that identical twins
responded to aerobic training with nearly identical progress. But
perhaps more importantly, the improvement in fitness as measured
by VO2 values varied significantly. The research showed that fitness
levels for twins can improve by as much as 97% :), or as little
as 16% :(. This huge disparity occurred with exactly the same training
load for each group of twins (Dr. Bouchard, Universite Laval, early
1980's). My guess is that the wide variation is due to differences
in relative fitness levels at the outset of the study.
Similar physiological studies demonstrated that spousal and sibling
pairings (not twins) had nearly identical responses to aerobic training.
Interestingly, the study pairs had remarkably similar improvements
when subjected to the same training loads despite significant differences
in genetic makeup. From this we must conclude that some sort of
common lifestyle factors led to their similar aerobic development,
not similar DNA. These lifestyle correlations can only be attributed
to factors such as nutrition, training habits, and perhaps, attitude.
Another interesting hereditary factor is that our mitochondria's
attributes come exclusively from the mother. Our mitochondria is
an area within our cells where all ATP (adenosine-tri-phosphate)
synthesis takes place. The efficiency of ATP production is critical,
as ATP is the fuel that determines how long (and how fast) we can
maintain our endurance efforts. In phospho-creatin fueled efforts
(lasting 20 seconds or less), or substrate level phosphorylation
(anaerobic efforts up to 2.5 minutes sans oxygen), the efficiency
of our endurance metabolism makes no difference...I'm talking about
pure sprinters here. But since you're likely an endurance athlete
if you're reading this, I hope you all "chose" your moms based on
Estimates tell us that roughly 30% of our athletic endurance speed
potential comes from our inherited genetic traits, with our day-to-day
actions determining the remaining 70%. For example: If we spend
many years of our life consuming globs of saturated fat everyday
for lunch (I'll have a double burger and a extra large order of
fries please!), our blood vessels will likely become occluded to
some degree (blocked of blood flow). The effects of this lifestyle
are especially unfortunate if during this same period we were sedentary
without the benefit of elevated training heart rates during aerobic
training and the beneficial HdL levels (plaque scavengers) that
allegedly follow. This sort of lifestyle may leave us physiologically old even though we may not be chronologically old.
In conclusion, we can either blame or credit our parents with some
of our athletic ability, but the bulk of our speed and endurance
is determined by the diligence of our training regime, long-term
lifestyle choices, and of course motivation. So the evidence clearly
suggests we should look for some new excuses -- and perhaps find
a significant other that's a heck of a lot faster than we are!