Is running just about doing as much work as possible and not getting injured?

One thing not mentioned yet is that it depends on the muscle fiber physiology of the athlete.

A slow-twitch monster typically responds very well to extreme volumes and mileage/training stimulus. Think about Solinsky running 90-100 mpw in HS at sub 6 min/mile pace (on easy runs) and even more later as a pro.

Put a fast-twitch runner like Coe, Brazier, or Rudisha on a 100+ mpw/program and they will get worse very quickly. There is a reason some of these runners found their ideal training volume in the 40-50 mpw range.

Even without looking at muscle fiber physiology, the same can be said comparing elite runners with average Joe's. The elite runner gets endless hours of PT, massages, long sleeps, perfect meals, etc. while the average Joe has to juggle his running endeavors with a 40-hour job, family life, 6 hours a night etc. Even if both are 70% ST (good for distance races like a HM), the elite runner can improve on very high training stimulus/work/mileage, whereas the average Joe might already get burned out at 60 mpw and start regressing at that training volume, even if he doesn't get a "hard injury" right away his race times and performance will gradually decline since his system is overloaded/overreached.

Muscle fibre type probably doesn't get mentioned enough. However average Joe doesn't really know what they are. He may think he is FT, but it is difficult to prove conclusively. Especially for someone who is older, and whose 100m time is not particularly impressive.

The important thing, is that a FT type will have endurance as a weakness, and so needs a lot of mileage. The mileage just needs to be run slower than a ST type.

Alfie wrote:

Muscle fibre type probably doesn't get mentioned enough. However average Joe doesn't really know what they are. He may think he is FT, but it is difficult to prove conclusively. Especially for someone who is older, and whose 100m time is not particularly impressive.

The important thing, is that a FT type will have endurance as a weakness, and so needs a lot of mileage. The mileage just needs to be run slower than a ST type.

This is true, but it's very easy to estimate average Joe's - 90% of population are around in the middle (which is actually more ST % in terms of pure muscle fibers since humans are ST in general compared to cats or other beings), which means they are neither extremely FT like a sprinter nor extremely ST like an ultra-runner or Ironman.

About how much mileage a FT guy needs depends entirely on the event. Runners like Ingebrigtsen or El Guerrouj are ST in the 1500 and probably get outkicked by runners like Makloufhi/Cheruiyot/Lewandowski or Ngeny if the races are/were slow enough, but in the 5000 they would be the strong kickers and are competing vs. more ST guys with better endurance.

Also, FT runners can build their aerobic system with other things than just mileage, for example Igloi-style aerobic intervals (think about LOTS of 100's/200's at decent pace with VERY short rests). What you should have said is they need to work on their aerobic system a lot. But grinding mileage might not be the right way for every FT athlete, some need more intensity (of course controlled, keeping lactate levels in the right range like with the aerobic intervals mentioned above) and others might just need to move down to a faster event.

In an ideal world every runner would train and race at the distance suited to their physiology. However, for many average Joes (especially older ones) it is neither practical nor desirable to run at the shorter distances. ST types won't race at the shorter distances, but many FT types will always want to race at the longer distances.

Many people are brought up on anaerobic sports and do insufficient endurance training. Average Joe may look like an FT type because of his prior training history, but how do we prove he is or not, without giving him a lot of mileage?

I am interested in your suggestion that lots of 100m/200m reps can substitute for mileage.

Perhaps muscle fiber physiology was not yet mentioned because it doesn't necessarily work the way you believe. For example, Coe was not a low-mileage runner. He was also not a natural "fast-twitch" person in the way that his contemporary Ovett likely was. He made himself into one through strength training. And Ovett ran a lot of miles as well.

As for Solinsky -- he ran 3:35 for 1500m. That's mighty fast for a "slow-twitch monster".