75min Z2 enough?

Makes sense! That was my perception too. I guess I just got bit thrown off by the posters who said you don’t get any benefit under X minutes of z2.


Clearly this is not a popular take with the SS crowd, but everything I’ve read says you’re right. 75 mins are by no means junk miles, but it’s not enough for the LSD benefits the OP is looking for.

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The OP said he’s doing LV plans plus 2-3 days of Z2. That is a solid approach to using TR correctly - LV intensity sessions + endurance riding. I think that’s about as good as you can get on about 6 hours per week.

Once the weather warms up, he’ll be even better if he can do some 3+ hour endurance rides on Saturday or Sunday.

I believe the Z2 work is cumulative. Think of it this way - if you do 2x75min Z2 all year that is 75 hours per year of training. That is a huge amount of aerobic fitness training for someone on an LV plan.

It also depends on what people are training for. For example if you are training for a century or big fondo you can do a progression where you start with a 2 hour endurance ride, then a 2.5 hour, then a 3 hour, then a 4 hour, and then a 5 hour.

After a 5 week progression like that and a rest week, you’ll be ready to rock your event.




Every little bit helps. Don’t believe anyone who claims otherwise.


I can name that song (increase mitochondrial biogenesis) in 12 minutes.


Wasn’t he talking about riding at LT1 and not in the zone below it though.

Is this a game of guess the animal on the treadmill? Was it a badger?


That, I think is my take, 75m is enough but a minimum (more is much better.) IMO for 75m you need a bit of Z3 in there, assuming for the individual Low end Z3 is under LT1.

Having said that on a TR LV plan every little extra helps, any extra Z2 over an hour is going to help but obviously not as much as 90m to 5hr. It depends what your general background is, and where you are on your progression as an athlete.



If prior to doing 75min Z2 rides on endurance days, you were doing 60min Z2 rides (for example), then yes, that is enough to improve. If prior to doing 75min Z2 rides you were doing 90min Z2 rides, then you’re likely just doing enough time to maintain.

Once you have adapted to doing the 75min Z2 rides, you will have to progress it (more Z2 time, maybe introduce tempo, etc.) to improve.

As others have pointed out, 75min Z2 is well worth your time.


The question will be whether a 75 min Z2 ride is challenging for you. For Z2 is normally the duration that challenges the muscles. Z2 for one hour might be easy, easy for two hours, easy for three hours, moderate after four hours, hard after five hours.

You’ll want to progress the duration which will progress your endurance. You should feel fatigued after your Z2 ride.


@PhilW jinx! :joy:

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My take on it as well. If by doing it you are going some way to maintain your aerobic fitness then by definition you are not losing it which in its way is a gain.

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Exactly, and sometimes that’s exactly what you want (perhaps because you’re “progressing” something else). :+1:

Rats, of course. You’ll be hard-pressed to find comparable human data, though, so worth something.

I really want to see a study on this exact issue. Why is 3 hours the magic number, and is 3 hours in one to better than 5 hours cumulative over the week in 5x1hr sessions etc.

Also what about if I’m doing an interval set which lasts 2 hours. If I add one hour extra at Z1 do I get this magic 3 hour adaptation or not because it wasn’t all steady at Z1?

If 3 hours is the magic number then how many of these should you be doing a week to be a beast.

You hear it a lot about splitting up the Z1 long weekend ride if you can’t make time for one go. Is that really the same, sounds like a good one for the TR podcast though maybe it’s been covered.

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In a polarized plan, ANY work above Z1 means it wasn’t a Z1 ride. The idea is, for example, to do one REALLY hard ride, and then all the other rides for the week purely in Z1.

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Can it not simply be 80/20 time spent? You’re already out in the bike, nice to just add in some Z1 work after intervals. Pros do it too.

That’s not how polarized training is defined.

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You won’t find it, because it doesn’t exist.

Nobody in their right mind would attempt to do such a study in humans, because the external validity of the results would be meaningless.

About all that can really be said is that the fitter you are, the longer (or harder) you have to go to induce further improvements.

As other have pointed out, though, even if you don’t do that, at least you’re not taking time off, and going backwards as a result.