The following ideas stem from The Lore of Running by Dr. Tim Noakes (4th
Edition, 2001, Oxford University Press Southern Africa). It is an extensive review of
literature relating and interpreting the latest knowledge on training for
runners and (less so) cyclists. It is an impressive body of work and I
recommend it to anyone who has more questions than answers. Any
misinterpretations are my fault solely
Part 1
Anecdotal evidence exists crediting decreased training loads for exceptional or PR
performances. Current ideas of training are being questioned because of studies
that were determining how little could be done to maintain fitness, following a
training cycle. These studies showed that if intensity (quality) was maintained, then
training loads could be cut by 70% for three weeks without adverse effects on
performance. Naturally, once it was determined that quality was more important
than quantity to maintain fitness, eyes are turning to how little could be done to
reach peak fitness.
I believe that most endurance athletes train too much quantity (distance) and not
enough quality (intensity). For instance, many people in preparation for an Ironman
routinely leave out all faster paced workouts. Every day is at the same low intensity
and many hours are spent. I believe most of us can spend fewer hours training and
achieve greater results at the same time. I think this is especially true for the age
group athlete, who can't dedicate every day to training and recovering like a
professional can.
So why does speed training prepare us better for even long distance races? It
comes down to what affects it has on the muscles.
Hold your speed longer
Higher intensity running has more intense eccentric contractions with each
footstrike. These eccentric contractions are tremendous stresses to the muscle,
but with proper recovery times, have been proven to increase muscle elasticity.
Muscle fiber themselves increase their physical elastic properties, through creation
of additional muscle proteins, especially a protein called titin. Why is muscle
elasticity important? The structural improvement of added titin and resultant
increased elasticity is what eventually determines how much energy your leg
transfers from footstrike to propel you into your next stride. The higher the elasticity,
the more power is transferred, and the more efficient you are. As muscles lose
their resilience (which is a normal occurrence over the course of a long run) and
stop transferring power as well, each footstrike spends more time on the ground,
cadence decreases, and we slow down. The greater the structural support within
the muscles the longer this eventuality can be put off.
Greater energy stores
Glycogen production and re-production are a major concern of any athletic body.
Glycogen is the primary means of storing carbohydrate in our body. We store
glycogen in the muscle and the liver. Obviously, when we train, we use glycogen. If
we use a lot of muscle glycogen our body will "super-compensate" and store up
more glycogen in the muscle in preparation for the next bout. In general, if we use
more muscle glycogen, then the super-compensation is greater and we store more
(up to a certain point, of course). When we use more muscle glycogen we also
increase the body's efficiency at replacing these stores -- so we can replace it
faster as well. Speed training more effectively drains the muscles of glycogen
allowing them to improve their ability of re-stocking glycogen supplies. For
instance at 70% of VO2 max it can take over three hundred minutes to reduce
muscle glycogen to 5g/kg of muscle and at 85% of VO2 max it only takes about
110 minutes. Doing intervals at 120% of VO2 max that time is cut to about 35
minutes.