Phases Pt. II: Lydiard and Aerobic Running ("Laying the Base")

Continuing the discussion on training phases--or cycles if you prefer--let's review Lydiard's model a bit in a general sense.  If you don't count the one for continuation of racing, he breaks the training leading up to the first major race into seven phases.

The first cycle is all about aerobic endurance.  It's probably where most track guys (and girls) are right now unless they've got business in Beijing.  The major goal of this first phase is metabolic:  We want to increase our body's ability to go longer and faster with less energy.  This is primarily accomplished through making more blood available to the muscles via new capillaries and increased stroke volume, but we're also talking about shifts in substrate that I'm sure I'll get into later.  For now, back to Lydiard...  It is a misconception that Arthur Lydiard was a big advocate of straight long, slow distance as the foundation for success.  When he talks about aerobic running, he is in fact talking about runs a bit under steady state.

From his book:

"My most frequent admonition to athletes and coaches is:  train, don't strain.  Bill Bowerman quoted this phrase in Coaching Track and Field to support his LSD principles.  But, it applied more accurately to running at faster aerobic speeds than are implied by LSD.  East German physiologists have shown that it's better to do long aerobic running at between 70 and 100 percent of your maximum steady state.  Lower aerobic effort, while it may be fine for joggers, does not exert the same desirable pressure on the heard and the cardiac and respiratory systems that an athlete needs."

From the section devoted to marathon training:

"Stamina is general cardiac efficiency and the best way to develop it other than cross-country skiing is by running.  That running is best done at just under your maximum steady state, for approximately 160 kilometers a week.  This is quite apart from any easier supplementary running, such as jogging, that you feel inclined to do."

Let's do the math here.  Two fartleks, two time trials, and three days of long aerobic running.  Yeah, that probably does give us about 160 km or 100 miles of aerobic work, and this, Lydiard says, is what yielded the best results when he experimented on himself with weeks between 80 km (50 miles) and 500 km (312 miles).  (Imagine doing a 312 mile week of pretty peppy running.  As much as I'm a fan of Lydiard, I've never bought into the whole "I tried this on myself" routine.  A) Who knows if he actually did it.  B) Who knows how long he did it for.  C) A sample size of 1 isn't the best indicator of a physiological effect.)  The supplementary running he speaks of is indeed the go-as-slow-as-you-like type of work and even if you could go faster doing it, you probably wouldn't want to knowing what was in store for your afternoon session.  The supplemental work was crucial, however for "assisting recovery from the long aerobic effort and hastening the rate of [his] development."

Why is this?  I thought we had to be running aerobically to get benefit.  The not so secret answer is that virtually all running--save specific portions of faster repetitions--is "aerobic," as is everything else we do during the day, including sleeping or typing on the computer.

Sure, Lydiard's "aerobic running" refers to the sub-maximal steady state running that some runners today might refer to as sub-threshold or tempo.  This doesn't mean that he doesn't recognize the fact that gains will be made with runs of only 15 minutes or runs where your HR doesn't exceed 100.  I'm with him on this to some extent.  Some of the types of results will not be the same as with the quicker runs, but the vast majority of adaptations will come in the form of marginal gains.  Equal gains through slower running will only be attained through more time spent out on the road or trail.

So why do we start with over-distance training or "the base" if you prefer?  I'll split this into components that most modern day runners will be familiar with and work within the stress-adaptation model.  Almost none of the adaptations are taken directly from Lydiard, but rather from the literature.  Most are topics that command their own multi-post examination, so the following are only snippets.

General stress:  Aerobic running

Component stress:  LONG RUN

Adaptations:

a) Neuromuscular:  More synapses along the muscle means better cortical and subcortical control (less drive required for same effect)

b) Capillarization:   Oxygenated blood reaches muscle fibers more easily

c) Autoregulation: Acute at first but lasting after 10-14 days (refers to increased diameter of the existing capillaries; also has the effect of getting more blood to the muscles)

d) Blood quality:  You'll see an increase in blood volume (dilution) at training onset since this is the only way to stimulate blood marrow via exercise.  End result (3-4 weeks) is blood with more RBC's provided nutrition is right.

e) Substrate shifts:  Glucose to fat is the big one.  Endurance athletes actually have a higher concentration of free fatty acids in their blood since their body is trained to only use the more readily broken down glucose when it needs it most.

f) Bone:  Stress on bone means restructuring to better cope with future stress.  Since we're off the major physiological adaptations, I'll stop here.

Component stress:  TEMPO/PROGRESSION RUN

Adaptations (refer to above)

a) Yes, but hard to say to what degree relative to the long run--probably less.

b) Yes, and stronger than long run.

c) Yes, and stronger than long run.

d) Not a lot of the mechanism above.  Instead, the big benefit is in the lungs where more alveoli are made available for gas exchange and the result is a more efficient exchange between alveolar air and hemoglobin.

e) Most tempo runs rely on a mix of substrates.  Tempo runs should be done at steady state or just below.  If you pass this level, you will know it within a few minutes time, but the resulting agony is not the result of a lack of glucose/glycogen as would be the case for the long run.  Rather, oxygen has become the limiting reagent.  That's what's nice about the progression run:  It keeps you within yourself and allows for the body to move into steady state (or even adapt to a dynamic version of it) at its own pace.

Component stress:  FARTLEK

Since I have only started (re-)including this into my own training in the last few months, I'm still discovering a lot of features relating to the fartlek run.  For one, I think it's a nice way to touch steady state with longer bursts and not get in over your head.  Two, and perhaps more importantly, it's a way to transition into interval work.  But that is a tale for another day, isn't it?