Ideal long run duration--60:00 or 2:00, nothing in between?

Fortunately humans are not rats and rat training principles does not entirely apply to humans. Though many aspects may be similar we have physiological differences and therefore even when testing drugs they use genetically engineered mice and rats that have human cells systems.

Personally my long run recipe is 80 minutes of progressive running. In my case (16:20 5k runner in mid 30s) I'm averaging about 6:15/pace.

When I was younger I did 90-150 minute slow running sessions and honestly I think that this 80-90 minute faster session yields much more benefit.

remember, these are rats. You need to divide time by four and multiply by two to get the time per pair of legs, so 2 hours for a rat (quadraped) is 1 bour for a human (biped).

Dont get me started on the relative endurance of a long distance millipede.

Also reading the article there is tremendous flaw by the author in assumption how fibers are recruited and therefore trained.

The author writes: "I was okay if I ran hard enough to force my body to recruit my fast twitch red fibres (and as long as they had enough glycogen). [...] in all my 3 months of training my slow twitch were being bypassed on every training run. (Or rather, recruited, but swamped/overworked). The intensity of each training run was too high for them to be stimulated optimally to best create mitochondria in themselves (and thus improve). So when I ran at a pace that I was forced to access ONLY them, I was sunk."

You see fiber recruitment always happens as a ladder. At first type I (ST) fibers are recruited. If the speed/power required to produce desired muscle motion is not sufficient that can be generated by type I fibers, type IIa (FOG) fibers are recruited in increasing numbers of motor units. Still not enough? Then type IIx (FG) fibers are recruited . The fitter you are, the later and less motor units of next fiber type are recruited. Slow twitch fibers are recruited always at any speed and peak recruitment of all ST motor units is achieved at 80% VO2max even in world class elite runners and about at 60% for untrained (that's why you need to go below 75% VO2max in recovery days – not to recruit FOG fibers as they won't recover for workout/race otherwise).

But if you wan't to train FOG fibers you need to recruit them. This can be done in two ways. Directly going fast enough in the workout to use them (like marathon/threshold pace). Or by going long enough slowly to fatigue ST fibers and push the body in recruiting increasingly more FOG fibers. Usually it takes around an 70 minutes before ST fibers start to fatigue at slow paces so it's only after 70 or so minutes of running slowly when you'd start recruiting and training FOG fibers.

Is there a way to equivicate Vo2max to heart rate? What is 60%, 75%, 80% of VO2max in terms of max hr?

Yes, you can convert VO2max to HRmax percent because VO2 max and HR max has linear correlation at least until you reach close to 100% of VO2max.

The generally accepted formula for conversion is as follows:

%MHR = 0.6463 x %VO2max + 37.182

But it's a bit harder than that because fiber recruitment also depends on the fitness level of an athlete and while elite athlete can cruise at 65% of VO2max on recovery days, an untrained runner would need to keep under 50% of VO2max not to recruit type II (FOG) fibers.

The same only vice versa applies to workout days. While for an untrained runner it's necessary only to reach 50% to start recruiting type II (FOG) fibers, an elite athlete would need to push to 70% of VO2max before even any type II (FOG) fiber unit is recruited.

So basically this is how to think about training principles:

With type I (ST) fibers it's an easy game – they are always recruited at any speed and peak motor unit recruitment is reached depending on athletes level of fitness with maximum number motor units recruited at 63% VO2max / 78% HRmax for untrained and 83% of VO2max / 91% HRmax for elites. As you see the ST max recruitment falls very close to the generally accepted "anaerobic threshold".

Type IIa (FOG) fibers initial recruitment happens at 51% VO2max / 70% HRmax for untrained and 67% VO2max / 80% HRmax for an elite athlete. This is the intensity I call the borderline grey area and you need to keep below this threshold at all times during easy/recovery runs. Never ever go above this on easy runs or you will compromise recovery of fast twitch fibersthat you wan't to save for workouts/races.

Type IIa (FOG) fibers peak recruitment happens at 76% VO2max / 86% HRmax for untrained and 100% VO2max / 100% HRmax for an elite athlete. This is the intensity at which peak fast twitch motor unit recruitment is achieved and going above that will cause only pain but no significant functional benefit regarding developing aerobic endurance. You can still go up there for short economy repetitions and speed work.

So bottom line is – run easy on easy days (never above 70-80% HRmax depending on your fitness level) and run hard but not too hard on workout days.

Ideal long "normal" run 70-80 min where you get a really good boost of mitochondria

and enzymes.This length of the long run is enough if you go for distances under half/marathon.

Ideal long run if you go for half/marathon will be 90min - 2 hours 40 min where you teach the body to work with glycogen depletion.

Thanks noko.

Is there any specific advice for more FT types doing easy runs? Can they run below 70% of hr max for same benefit?

Jan Stensson , Coach JS wrote:

Ideal long "normal" run 70-80 min where you get a really good boost of mitochondria

and enzymes.This length of the long run is enough if you go for distances under half/marathon.

Ideal long run if you go for half/marathon will be 90min - 2 hours 40 min where you teach the body to work with glycogen depletion.

What does glycogen depletion have to do with a half?

As I said I do long runs of 80 minutes and that is enough to get glycogen depleted if you recruit fast twitch fibers early as usually glycogen stores are enough for 40-50 during training week without carbo loading (which would give about 60 minutes). So you don't need to run 90+ minutes to get the benefit of glycogen deficiency just run faster.

I'm not sure you got the idea. FT fibers are for workouts and racing.

The only advice is to NEVER recruit FT fibers on easy runs. Save them for workouts and races.

That means never ever run above approx. 60% VO2max / 75% HRmax on easy run (assuming you are not an untrained and not an elite athlete). Untrained individual should not go above 70% HRmax and an elite athlete could be ok with going up to 80% HRmax however.

noko wrote:

Alfie wrote:

Thanks noko.

Is there any specific advice for more FT types doing easy runs? Can they run below 70% of hr max for same benefit?

I'm not sure you got the idea. FT fibers are for workouts and racing.

The only advice is to NEVER recruit FT fibers on easy runs. Save them for workouts and races.

That means never ever run above approx. 60% VO2max / 75% HRmax on easy run (assuming you are not an untrained and not an elite athlete). Untrained individual should not go above 70% HRmax and an elite athlete could be ok with going up to 80% HRmax however.

Great thread Niko. I think Alfie was referring to runners who are more 'fast twitch' orientated in their makeup, do such runners need to adjust their easy day / recovery pace at all? Or do the same principles apply?

Man... From where came this knowledge?

Do you have any recommendations for a good reading on this subject? (Aside from the outstanding one you already provided)

Forgot to quote it.

HITHEREYOU wrote:

noko wrote:

I'm not sure you got the idea. FT fibers are for workouts and racing.

The only advice is to NEVER recruit FT fibers on easy runs. Save them for workouts and races.

That means never ever run above approx. 60% VO2max / 75% HRmax on easy run (assuming you are not an untrained and not an elite athlete). Untrained individual should not go above 70% HRmax and an elite athlete could be ok with going up to 80% HRmax however.

Great thread Niko. I think Alfie was referring to runners who are more 'fast twitch' orientated in their makeup, do such runners need to adjust their easy day / recovery pace at all? Or do the same principles apply?

Sorry I did misunderstood the question.

The principle here is not to recruit the muscle fibers that you will train on the days of workouts. This means that you should keep the pace slow enough to recruit only ST fibers on recovery/easy days at all times even if you are a FT type guy as there wouldn't be any added benefit.

You see your heart and circulatory system is efficiently trained even at low paces as the stroke volume reaches almost full volume at 65% of HRmax. The rest is only the function of time – the longer you go the more benefit (unless you go long enough so the ST fibers get fatigued and you start to recruit FT fibers). So there is absolutely no added benefit of going faster on easy/recovery days. Just go by feel but keep below 70% HRmax. I would limit a single easy/recovery run to 40 minutes.

Work hard on workout days and go faster on long runs instead and you will be rewarded much more than by running few seconds per mile faster on easy days.

George213 wrote:

Jan Stensson , Coach JS wrote:

Ideal long "normal" run 70-80 min where you get a really good boost of mitochondria

and enzymes.This length of the long run is enough if you go for distances under half/marathon.

Ideal long run if you go for half/marathon will be 90min - 2 hours 40 min where you teach the body to work with glycogen depletion.

What does glycogen depletion have to do with a half?

It`s a link between increased speed and faster glycogen depletion in a half marathon race

compared to the pace you use in training. The majority of runners needs more than 90 min to complete a half race and the glycogen supply needs to be as long as possible.

noko wrote:

Is there any specific advice for more FT types doing easy runs? Can they run below 70% of hr max for same benefit?

I'm not sure you got the idea. FT fibers are for workouts and racing.

The only advice is to NEVER recruit FT fibers on easy runs. Save them for workouts and races.

That means never ever run above approx. 60% VO2max / 75% HRmax on easy run (assuming you are not an untrained and not an elite athlete). Untrained individual should not go above 70% HRmax and an elite athlete could be ok with going up to 80% HRmax however.[/quote]

Thanks noco.

I always understood that FT type runners had less ST fibres, and these ST fibres would tire sooner. The FT fibres would then inevitably be recruited sooner.

FT type runners had to run slower than ST type runners, on easy runs to ensure that the FT fibres were not recruited sooner.

Can the FT type runner train the same as the FT type runner on easy runs and long runs?

I know many runners who do easy runs at less than 70% of hr max. What are the benefits, and is it better to train at least at 70% hr max?

George213 wrote:

Jan Stensson , Coach JS wrote:

Ideal long "normal" run 70-80 min where you get a really good boost of mitochondria

and enzymes.This length of the long run is enough if you go for distances under half/marathon.

Ideal long run if you go for half/marathon will be 90min - 2 hours 40 min where you teach the body to work with glycogen depletion.

What does glycogen depletion have to do with a half?

I've read, but can't remember if it was on Healthy Intelligent Training by Keith Livingstone or on the website Science of Running by Steve Magness that running on depleted glycogen stores provides a greater training stimulus and by consequence a greater physiological adaptation than training with full glycogen stores.

Alfie wrote:

noko wrote:

Is there any specific advice for more FT types doing easy runs? Can they run below 70% of hr max for same benefit?

I'm not sure you got the idea. FT fibers are for workouts and racing.

The only advice is to NEVER recruit FT fibers on easy runs. Save them for workouts and races.

That means never ever run above approx. 60% VO2max / 75% HRmax on easy run (assuming you are not an untrained and not an elite athlete). Untrained individual should not go above 70% HRmax and an elite athlete could be ok with going up to 80% HRmax however.

Thanks noco.

I always understood that FT type runners had less ST fibres, and these ST fibres would tire sooner. The FT fibres would then inevitably be recruited sooner.

FT type runners had to run slower than ST type runners, on easy runs to ensure that the FT fibres were not recruited sooner.

Can the FT type runner train the same as the FT type runner on easy runs and long runs?

I know many runners who do easy runs at less than 70% of hr max. What are the benefits, and is it better to train at least at 70% hr max?[/quote]

As a guy that could barely break 60, I wish I had known I could have recruited fast-twitch muscles. I had a cornea transplant when I was in HS and I thought maybe the same thing could be done with fast-twitch muscles, but my doctor said a 60 second 400 guy would reject the FT fibers almost immediately.

Brazilian Guy wrote:

George213 wrote:

What does glycogen depletion have to do with a half?

I've read, but can't remember if it was on Healthy Intelligent Training by Keith Livingstone or on the website Science of Running by Steve Magness that running on depleted glycogen stores provides a greater training stimulus and by consequence a greater physiological adaptation than training with full glycogen stores.

Greater training stimulus of what? It`s not like that.Running on depleted glycogen stores teach the body to be more efficient in the energy process and use the glycogen stores more economically.

If it was true that running on depleted glycogen stores provides a greater training stimulus and greater physiological adaptation than training with not empty glycogen stores, elite runners would have done more than one of the usual long run per week.