Part 2 (of Speed Training)
Speed and Weight
The information in Part 1 does not mean that all athletes should go out and do
speed work. For the over-weight athlete the chance for injury is much greater:
impact forces when running at faster speeds can reach three times our body weight.
Certain structures in the lower extremity are particularly vulnerable to these
increased forces. Gaining as little as five pounds can affect some tissues.
Common injuries are:
Metatarsalgia
Plantar Fasciitis
Trochanteric bursitis
Patellar tendonitis
Achilles tendonitis
Athletes that are over-weight by 10-15 pounds or more should concentrate on
aerobic work. When they get into the 10-15 lbs range, they can then begin some
sub-threshold intervals. This slow introduction to increased pace can be safe and
can have the added benefit of increasing the rate of weight loss. Speed training
obviously burns more calories. It also can increase our basal metabolic rate. This
determines how many calories we burn normally throughout the day. As we get
more fit, we can burn more fuel, and it gets easier to lose/maintain weight.
Our bodies are very intuitive. When it recognizes that we are running faster more
consistently, it strives to do so as efficiently as possible. A lighter runner can
complete the run faster and easier than a heavier one and our body is aware of this.
Call it an evolutionary response----you will lose additional weight when you throw in
speed training.
On a personal note, I will routinely drop 5-8 pounds from my usually consistent
weight when I start a 5K training regimen. Without any alteration in my diet and no
overall increase in my training volume, my body sheds this weight because it is
receiving weekly input, during sessions on the track and fartlek trail runs, that I am
wanting to run as fast as possible.
LSD
All training does not begin and end with speed work, although, obviously, I think it is
terribly useful. Long slow distance (LSD) rides and runs are very important to the
endurance athlete. It is through these workouts that we mentally get prepared for
our longer races.
As I have written about in another article (Central Governor Theory) we are also
retraining our central nervous system to allow for maximal work over long periods.
Assuming we eat and drink appropriately, numerous LSD workouts will convince
our brain to allow for more muscle recruitment longer into a workout or race.
You might say our brains are skeptical and over-protective: if we try to ride for 7
hours without having ridden over 2.5 up to that point, we will definitely fade in the last
few hours of that seven hour ride. Our brain, in an effort to protect the heart and
other systems, will decrease motor recruitment so that less ATP is used (thereby
preventing it's total depletion or depletion beyond a critical level). If we use
progressively longer LSD workouts where we eat and drink enough to allow for
adequate hydration and blood glucose levels throughout the ride, we can "show" our
body/brain that there is less danger of reaching that critical level of depletion
because we are continually providing it with nutrition. There will always come a
point, however, where the well-hydrated and well-nourished body will have a drop off
in muscle recruitment and will fade or fail. (Happens all the time in 24 hour mountain
bike races and Ironmans) This is essentially the basis of the central governor
theory. But with diligent LSD workouts we can push back the point at which this
failure occurs.
Speedy/Efficient
To summarize a little, I think most endurance athletes neglect smart speed training
to aid their progress. Put simply: after speed training, if you can run more efficiently
at 10 mph , then you will run more efficiently at 8 mph (and you will be able to run
farther at 8 mph than you had before). It does not work as well in reverse: if you train
at 8 mph all the time, you will be able to run for longer at 8 mph, but it will do little for
your efficiency at 10 mph.
So you may say,"So what, both scenarios allow you to run farther at 8 mph and that
is all I want to do in a marathon or Ironman anyway." True, but doing the speed work
increased your lactate tolerance, so that if you need to "pick it up" a little to drop a
competitor, you would be able to do that; remember, you are now more efficient at
10 mph as well. There is less chance of having that ability with only LSD work.
Also, speed work simply takes less time. Most athletes are not professionals and
they cannot dedicate hours and hours a day to training and recovery, so being able
to accomplish more on less time is imperative for most of them.
Hope this helps