JK wrote: ?I believe a few other studies (can't remember them off hand) have shown that increases in mitochondrial density are most profound when training between 65% and 70% of heart rate reserve, which would correspond to roughly 74% to 79% of VO2max.?
One problem with quoting such studies (and I?m not criticising JK, he will probably agree with what I am saying) is that you always have to ask, ?what level were the runners in that study that showed improvement with such a training program?? It will make sense that the stimulus intensity for improvement will vary with initial fitness level. Beginners show improvement with almost any exercise at all, experienced vets will not show improvement with low intensity running (unless they go a very long way), although this might be valuable for maintenance or recovery.
So whereas it is true that all runners should begin at this ?low? intensity (and a surprising number of runners skip this stage and forever after wonder why their performance plateaued earlier than it should), the real stimulus to peripheral development is to train at the running pace just prior to an increase in blood lactate. The intensity here is crucial.
The pace at which this occurs can be improved substantially with training. So much so that when Paula says she scoots along at 6.00m/m, we can be pretty confident (and she will know for sure) that her blood lactate is around 1.2-1.7mM if not lower. (I don?t presume to know any more about Paula?s training than anyone here. But we can logical deduce some things).
Most of the cool dudes on here though, who claim to run at 6.00m/m on their easy/steady runs, will be nowhere near as comfortable. Which is why Paula?s rate of speed loss is very little as she moves up in distance. Roughly these are as follows: 3k-67/lap; 10k-72/lap; marathon (equiv)-78/lap. Only extremely well trained males could hope to match those lap times over the whole range of distances.
So, why the 1.2-1.7mM? Well, with such low values, Paula can be sure that her aerobic system is supplying all the energy required for the particular pace. Which is perfect, because that is the energy system she is trying to train on such runs.
If one of us were running alongside her, even with similar HR values, yet had a lactate of 3.5-6.0mM (very possible), then despite all our protestations and macho crap about how good we were feeling, we can be sure that if we go long enough, we will crash long before Paula.
Even if we manage to complete that particular training run with her, her peripheral aerobic development will have been optimal while ours will have been disastrous and probably require a recovery the next day.
HRs, on their own, don?t really tell the complete picture. Consider some of the ?in-sight? articles we often read of Kenyans training at 80-90% of max HR. This might even be true, but instead of trying to copy those HR values in our training, it would make more sense to run at the Kenyans? blood lactate values (which are low, according to the same articles).
So, with optimal training, it is possible (in time) to be able to run at higher HR values with commensurate low lactate values. This is what allows the studs to run stunning marathon times.
Note also that such training, as a by-product, increases fuel economy, allowing you to burn lipids rather than CHO. This offers a number of advantages, not only in the marathon. It also means that you can train at this intensity more regularly, since there is no need for a long CHO replacement period (48+ hours) in your leg muscles. Since you are fuel-economical, 100+ mpw becomes more possible without breakdown.
Although in time this training pace can become fast, it is never really hard. A large percentage of it will always be slower than marathon pace, but not by much. If we consider that KK?s marathon pace is 4.46m/m, then a sub-LT run at 5.10m/m is no big deal for him in terms of effort, and is a pace he will be able to hit quite regularly in his training week.
So, why do the Japanese run such slow paces as the major part of their training?
I will say, up front, that I have no experience of such Japanese training. It may be that it is psychologically ?not agreeable? with Western minds (Legalizit will back me on this). I am interested to hear if Jason can deal with the boredom of 100+ such miles per week. Since he appears to have a ?low-boredom? threshold, he may not find it easy. Hope he keeps us updated.
Well, to understand it better, and not just to say it is for the tendons/ligaments infrastructure, we only have to look to Snell?s research which showed that even the fast fibres are recruited (and thereby trained under fully-aerobic conditions) when the slower fibres become fuel-exhausted. (see also the study of Green and Patla above, from ET).
Assuming this to be the prime cause of the Japanese peripheral aerobic development (which undoubtedly works), then the athlete must undertake a lot of miles, since progressive fibre-exhaustion is required. That?s the physiological explanation. The coaching schedule might also be coupled with a diet regimen that restricts CHO to a certain extent to ?hurry? this exhaustion. On this latter point I am not sure, but it seems logical. Jason might tell us more.
Notice that Jason complained in one post that 8.00m/m were tough. The reason for this will be that he will not be eating sufficient CHO each day to completely refuel his muscles for the next day?s mega-mileage runs. If he continues with this schedule, he will become (in time) progressively more economical (and burn more fat), and should find the mileage easier to deal with. But remember, he is required to almost run to fuel exhaustion on a regular basis for the program to work.
Slow Japanese-type training aimed at peripheral development absolutely requires mega-mileage. It will not work to anything like the same extent on a 40-50mpw (to answer the original question).
To continue to answer the ?miler? question. Such training is not what a miler would want. A miler absolutely needs to be able to create high lactate values for speed. A miler who can only achieve a maximum of 8-10mM (?true? marathon/distance runner max) would be nowhere in a mile race against guys who can unleash 15mM+ of energy. A miler does not want to convert the IIb fibres. Although he should train to maximally oxidise the type I and type IIa (see Lydiard?s marathon-type training plus hills and speed, for a potent mix).
That such training is so widespread and successful in Japan (and their relative lack of fast milers) may lie in their genetic make-up. It may be that the general Japanese slow/fast mix is more naturally akin to what we would call the ?natural? distance runner (80%-20%) than that of an average Western adult (50%-50%). Their low-meat protein diet may also be a factor in a reduced percentage of fast fibres. I don?t know. Obviously a high natural percentage of slow fibres is almost mandatory for long distance success.
I?m only speculating here, but again, these seem logical premises and worthy of study (although such genetic topics can be sensitive).
One main advantage of the Japanese system that I can see, is that it is almost impossible to overtrain. Unless a runner has increased his weekly mileage too rapidly, the prime cause of overtraining is generally too high intensity. This is avoided with the Japanese way of training. So there will be fewer cases of burn-out. If the athlete can overcome the banality of the daily mileage (and it may suit the more patient Oriental mind here ? ask Legalizit), then if they have a suitable slow/fast muscle fibre mix, it seems almost inevitable they will achieve long distance success.
A disadvantage to the Western system? It is too easy to overtrain; you really need to know/monitor what you are doing.
Apologies for the long post. Enjoyed the topic.