why should a 1500m runner train at race-pace or quicker except when gettin ready for summer-track season?
There is no need to train the anaerobic system for longer than 4-8 weeks per year, aerobic training starts at 3k-pace, training above 100% Vo2max is pretty useless for conditioning.
That what you say i consider one more "american mistake", a myth or a wrong preconceived idea that you train missing a pace effort or a work in equivalent physiologic efforts and that "as a miracle" you use the "miraculous" taper and peak and your body are ready to shape in 6-8 weeks in hard efforts.
Historically that´s derived from Lydiard ideas and Lydiard periodisation, but that´s more a misunderstanding about Lydiard method.
Under that training philosophy i understand better now why most americans they claim that they are not satisfied with their performances or they don´t improve as expected.
Physiologists they say that more than 10 days missing or ignoring the use/exercise in a certain training zone level you start loosing something of your physical capacity or to recruit yours cells in the several human systems that work to perform a certain effort.
For example. It means that after 10 days ignoring the specificity of a pace - speed, anaerobic, race pace, lactate management or aerobic etc - the twitches / fibres cells that are needed to r recruit that “effort zone” (speed or race pace etc) - some of them starts to die after a 10 days period, and you loose some of that capacity. Physiologists they also estimate that a period 3 times longer that the period that you miss that effort are needed to build up the same earlier capacity, but sometimes longer and sometimes there´s no return. You miss that completely. That´s not new the stories about runners that did a sustain progress and train regularly in their careers and that after missing training for a long period during, ex: due to a serious injury - when they want to come back they are unable to come back to the same performance levels that they did before, despite they train hard and right for a long period looking for a come back in top-shape. So a few times the lack of a certain located effort training that miss takes the come back impossible because the lost by the unused that´s irreversible.
Here there are several problems, several obstacles to our target. That 10 days that´s not enough to exercise in and training efforts/levels that we might, and besides we need days to recover - another body need.
So, ther´s no change if not to select from what´s essential in each training period/phase, but trying to come close to specificity, or specific training soon as possible. That poses another problem is that apart to the "specifics of the specifics - read race pace and faster" we need pace supports in intense paces but slower than race pace - thus you are right that for a 1500 goal target 5000m pace that´s a pace support in earlier season, but you are wrong if you think that you get any benefits by missing specifics for too long.
Another obstacle that´s if you come out of a rest period, or an hard period, you can´t enter in the specifics without a intro period that you train the basics (pure aerobic)- thus easy runs and also the pace support (aerobic endurance) -thus intense threshold runs.
Of course that the workouts formats to stimulate a physiologic activity are so many. You can train anaerobics using workouts in an anaerobic pace/faster than race pace, or dong hills reps, or doing strides or doing weights !
And you can train your body and muscles in faster paces than race pace by doing short strides. But the “specific of the specifics” that are training in race pace (or close to the race pace) and faster than race pace really.
Now, in that scenario, how you pretend to loose a determined training effort for a long period (6 to 8 and half months) and recover quickly that quality or improve that your quality in 4-5 weeks. Only by miracle !
But more strange and curious to me. That are the same persons that advise that we may train 2 hour long runs EVERY WEEK for a 800m-1500m target goal - also during the taper period - or we will loose that aerobic power that are the same people that thinks we can miss 8 months of a so specific training as "anaerobic endurance and aerobic power" - faster than race pace.
Of course, in a training technique while building up an entire season we need to analyse how long it takes each phase, and what´s each pace need. That´s not the same to peak once a year or twice as Rui Silva does (indoor and outdoors) or 3-4 times a year round as "all terrain" runners they do - cross/track/road. But we can´t miss no one specific pace for too long - or we are loosing the efficiency to use our talent.
Besides, “faster than race pace” or race pace that doesn´t mean necessary very hard and delayed anaerobic efforts, those that Lydiard says that german physiologists said you can improve more than 6 weeks. That anaerobic pace are max.pace for a set distance, really anaerobic/lactic pace. The pace considered faster than race pace i´m talking about – that´s 100% to 105-107 % race pace, that you may train not necessary for longer total mileage workouts, but by the way for 1 to 2 miles in sets with complete recover.