Polarized Zone 2 question

During a single effort or exercise session how long do you have to do zone 2 to get the benefits during a polarized training program?

I find that I get challenged mentally enduring a two-plus hour training session for zone 2 and was wondering if there are specific adaptations that require over 2 hours during a single session to be realized?

I guess my real question is can I get away with my zone 2 days only being about an hour?


it depends, any volume is good but the more saddle time you can get, the better. I do 14hrs a week inside, and it takes some building up but I would suggest seeing what you can do with your environment and maybe even your fit to help make inside sessions feel less terrible


What I’m trying to figure out is what are the specific benefits of doing a two or three hour zone 2 session as opposed to a 1 hour session?

And if a two or three hour zone two session is good, is a four or five hour zone 2 session better?

The way I look at it if a one hour Z2 session gives me 90% of the polarized zone 2 benefit then I’m not sure it’s worth it to me in particular to do that extra hour.

Any coaches out there that could weigh in on this?
I genuinely appreciate it

again, it depends, 1hr for me is a drop in the bucket and not really worth doing that little time unless i’m actively recovering, if you aren’t well trained yet 1hr might be huge. It’s really impossible to answer wit the exception of trying to ride more instead of less when you can


I appreciate the feedback.

1 hour outside is fine, indoors I just seem to get very mentally fatigued on the trainer.

Currently for this year I’m at 5,500 mi. I race MM50+ Cat 4 and whereas I know I can get fitter. I don’t think fitness is the issue and more specifically for my own personal training I want to understand the benefits of going longer during a zone. 2 session

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ultimately, cycling is a sport where volume is king, if it weren’t we’d all just do a few short intense sessions and be done with it.


Again, thank you, but you aren’t answering the questions posed…

and again you’re asking an impossible to answer question!

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If you think 1 hour z2 rides are enough to make you fit enough to ride for an hour, then you won’t be disappointed. If you expect them to make you fit enough to race for 5 hours, you’d be wrong. It sounds like you don’t like to ride very far anyway, so stick with the short ride approach. Nobody says you have to ride more than you want to.


I’m not making my point…

Dr. San Millan puts it at 75 minutes 3-5 times a week for Z2, but his Z2 is more like what most call tempo… Won’t be enough to win the Tour de France, should be enough to move the needle for most mere mortals.

But that topic’s been beaten to death in the forum lately, so you probably already knew that :wink:


Nobody here is missing the point. Your answer is more is more. Do as little or as much as you want to. There is no answer to the dropoff of diminishing returns in the scope of your question because if this is your question you aren’t even doing enough to see deminishing returns.

Training zones aren’t magic. You get out what you put in, more is always more to the point that you’re still recovering.

Given whatever volume you end up doing you’ll keep adapting and improving to the workload. Until you plateau… then that’s when you can ask yourself again, “should I ride one more hour?”

Build what you can and want to. Then reflect on what you’ve done. Evaluate if you want more and adjust. It’s simple as that


I appreciate your feedback.
My specific question is in regards to polarized training and adaptations that occur during the zone 2 segments of training.

I’m specifically curious if there are additional adaptations that require two plus hours of zone 2 training.

I understand that any training program you get what you put into it but like many of us I only have so much time for training and I want to maximize the time I have available.

There’s nothing magical about 60 minutes, 120 minutes, or any other arbitrary duration. Your body is blissfully ignorant of these things

The longer you ride at an endurance intensity the better, until you ride too long to recover from it.

As others have told you, you’re asking an impossible (IMO the wrong) question. Don’t think of it as how long do I need to ride at this intensity to make it worthwhile.

Instead think of what you’re trying to accomplish with your training and what your rate limiting factor is based on your current distribution. If you’re constrained by time and not fatigue, try adding more intensity without increasing time. If you’re constrained by fatigue and not time then try reducing intensity and increasing time at lower intensity (or adding more recovery time)


There’s too many variables for an informed response regarding adaptations over increased time in zone 2.

Previous training history, training hours per week completed and available, how you have adapted to previous tranches of intensity to name a few considerations. Have your tried volume to move the needle previously and how many hours were utilised weekly? Etc…

Is commuting an option? Two sessions per day are a great way of adding training hours to your calendar and have provided me steady and so far consistent gains.

You also need to ensure your z2 training doesn’t not diminish the compliance, consistency and completion of the higher intensity sessions per week.

One hour sessions are fine for me commuting and a 2 to 4 hr outside z2 ride on a sunday plus two one Vo2 and threshold session per week.

see what works for you and don’t be too wary of mixing things up to keep the gains coming through. Use the intense as the most important workouts whilst ensuring the hard efforts are very hard and utilizing z2 time period/z2 intensity whichever works for you each week.


To address this directly, if you insist on a polarised distribution:

Assuming you’re doing an hour of Z2 per day and not doing double days, and assuming you’re going to take one day off per week for recovery, that leaves you one day per week to do 1 hour of intensity and a bonus day off by default, which you’d then replace with another hour of Z2 on that day.

6 hours per week in total. 1 hour at intensity. If that’s VO2 Max then that’ll be a maximum of 25 minutes time in zone per week.

That’ll be enough to progress until it isn’t. A couple of months, maybe.


Thank you all for your suggestions and input. Very much appreciated.

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The answer is that when you ride long, you fatigue your slow twitch fibers / smaller motor units. Once that happens, you start recruiting larger motor units and faster twitch fibers and start to train them oxidatively (build mitochondria and capillaries).

If you only ever go an hour, your slower twitch fibers will get pretty good at riding that hour and you’ll never recruit the faster fibers and train them for endurance.

(Before people pick that apart, I’m not an exercise physiologist, and that is my layman’s understanding for the why we go long. Anyone else can feel free to elaborate.)

That said, you can get pretty fit on an hour. If your races are like 45 minute crits, then maybe you don’t need 4 hour rides.

Other hacks may be to up the intensity - tempo or sweet spot - if you are only going to do an hour. There’s nothing magical about zone 2. Everything under threshold is aerobic training but you can only do so much the closer you get to threshold. Usually people that do the longer training rides are riding in low zone 2 or zone 1.

The fact is that if you are going to race, your top competitors will be doing the 10-15-20 hour weeks to gain an edge. My team mate did 15-20 hour weeks plus some altitude training to train for and win the Tour of the Gila masters B category.


This is great, thank you.

The info on the bodies biomechanical response is what I was looking for.

I need to up my mental game…I think I have convinced myself that I “don’t like” indoor riding, and its a self fulfilling prophecy. I just get bored.

I only do a handful of Crits a year, so I don’t want that to be my focus. My longest road races tend to max out at 2 to 2.5 hours, some gravel events are much longer.


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It may help to binge-watch some TV shows, or movies while you are doing zone 2. I also get off the bike for about 3 minutes every 45 or 50 minutes … however long it takes to break my zone 2 indoor training into equal blocks. In a 2 hr 30min indoor zone 2 ride, I get off the bike every 50 minutes. Indoor riding is hard on my rear. Plus it helps to mentally break it into blocks. Outdoors is a different story. I only stop when it’s a necessary bathroom situation.