Randy Todd of Wisconsin wrote in recently with a few queries  about Base training and sub-threshold (”3/4 effort” ) runs.

Q: “At the very top of page 85 you wrote “A strong run for an hour at 1/4 effort during the aerobic base would be equivalent to a run just below the anaerobic threshold, or marathon pace.

Six lines down you wrote “strong “3/4 effort” runs of about an hour, at about 90-95% of anaerobic threshold speed- or, really, “marathon pace” are the best.”

In the first sentence you associate marathon pace with 1/4 effort, and in the
second sentence you associate marathon pace with 3/4 effort.  Is this a
mistake, or am I misinterpreting what you are trying to say?

A: This was a misprint by publishers. The answer is ¾ effort in both instances. 3/4 effort by my interpretation can be roughly said to be 75% (3/4) of Heart Rate Reserve, for those addicted to HR monitors. This in turn, is about 90-95% of anaerobic threshold (15k-21k race pace) speed. So it’s strong, but comfortable, and builds you without tearing you down.

These next questions came about when I compared information about Lydiard’s recommendations for base training: and what Robbie Johnston wrote when comparing Walker’s and El Guerrouj’s “general preparation period”, and information from Part II, For the Nerds (that me!).

Q2: You mention several times that in the aerobic base phase that acidosis is to be avoided.  But in part II, For the Nerds, on page 195 you wrote  “once the highest possible level of aerobic efficiency has been reached, intense running at 95-100% VO2 max is necessary; i.e; longer intervals with equal recovery at 5000m to 3000m pace but no faster.”

A2: The quote on Page 195 is straight from the researchers’ abstract. The interpretation or conclusion is mine.

The research being looked at ISN’T about base building, per se, it’s about VO2 Max. As it says, well-trained distance runners often plateau in measured VO2 max, while still improving their performances. HOWEVER when they perform work at higher intensities than normal, their measured VO2 Max is enhanced.

More questions are raised here : does this newly raised VO2 max then translate to an automatically higher threshold pace in terms of %VO2 max, and an increased performance? Or does the athlete’s threshold speed (and therefore performance level) remain much the same?

I don’t know for sure, but I’d tend to think that the intense work would stimulate a higher threshold speed.

At the end of your base-building period, the AEROBIC contribution to VO2 max should be at its highest, awaiting the higher intensities to top off the ANAEROBIC contribution to VO2 Max.

I refer you straight back to Pg 64-6, Randy, where we look at the two energy system contributions to VO2 Max. The one that takes the longest to develop, over many years, is the aerobic contribution.

Above that level, a lot of the measurement of VO2 Max is actually done while the body goes into very anaerobic metabolism, and this anaerobic metabolism can be developed and topped off in a matter of weeks in an aerobically fit athlete (some experts like George Gandy maintain that an aerobically very fit athlete is only ever 6 weeks away from a PB).

Q3: According to Robbie Johnston’s chapter, in both Walker’s and El Guerrouj’s “general preparation period”, they were doing repeat runs of 1km or 2km from 3km to 5km race pace, which is beyond the anaerobic threshold.

So does this mean that when people with the physiology of Walker and El Guerrouj get to a certain point of aerobic efficiency, that the rule of avoiding acidosis during base phase stops applying to them (as long as they don’t over do it?)  Or am I misinterpreting this?

A3: No, you are not misinterpreting this. The “not overdoing it” is the big point.

Experienced athletes with a substantial aerobic base developed over years can safely introduce small but pivotal amounts of higher intensity intervals in their Preparation Phase, and this serves a purpose by maintaining IIA fibre metabolism. These fibres are the ones most useful for middle distance I’d say. Always, this work is done in a largely aerobic context (ie: runs done prior to and after these sessions are usually at the athlete’s recovery aerobic levels).

As I mentioned in the book, it’s almost impossible to even do a long hilly run without going near or into some acidosis somewhere, but the principle is to limit acidosis as much as possible while running for as long as possible in mostly aerobic zones.

As you’ll understand, IIA fibres can be trained to glycogen depletion quickly by VO2 max intervals, or slowly by very long runs.  Two completely different types of running will stimulate the muscle fibres to make a response. Either way will result in an enhanced performance potential of the IIA fibres.

The first type of training takes the athlete into systemic acidosis, stimulating buffering biochemistry in the liver and at the cellular level. It’ll do this fine if it is trained and recovered from aerobically, 1-2 times a week for about 6 weeks. It doesn’t develop capillarization really: in fact it can inhibit it if overdone.

The second type, Long running, depletes the IIA fibres of glycogen eventually, (the desired “tired, heavy legs” effect) and has the bonus of SAFELY stimulating capillarization as well. A stimulated muscle fibre will respond, once recovered, by increasing its size or surface area across the muscle belly.. and if we can do this, then we have increased the available volume of IIA oxidative/glycolytic fibres to be trained specifically later on.