Lactic acid threshold combined with long-ish Zone 2

Hi all,
I’ve been noticing some pros appear to be incorporating threshold efforts or intervals at the beginning or middle of long Zone 2 rides. This seems like a sensible practical workout, especially for the kind of racing I do (50-70 mile gravel). I tried the other day to throw a 20 minute lactic acid threshold effort into the middle of a 3-hour Zone 2 ride. On the one hand, I had a much harder time than normal completing that threshold effort (actually I had to cut it short, which I never do), but then I was pleasantly surprised that I was able to return to high Zone 2 and pretty fully recover within about 5 minutes of struggling, and felt ok, maybe a little more tired, for the remaining 1.5 hours. While this isn’t really targeting time in Zone 4, it does seem like recovering from Zone 4 efforts is worth training for my type of races. Thoughts on this type of training as an occasional or race-specific thing? I’m thinking this would help train for a hill climb attack mid-race where I have to try to hang on for the second half. Is this reasonable?

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Indeed doing threshold intervals and intervals of all intebsities within a long zone 2 rides is great. When you look at your trianing it needs to match the demands of your events, in your case long gravel events which require you do have to put out longer susatined efforts and even short high power efforts any any point on the course. Incorporating intevals in the middle or even end of a long zone 2 rides helps to develop and build fatige resistance which is your ability to go harder longer. I like placing threshold or fatige resistance in rides towards the end after you have accumiated some fatigue, do 4-6x2.5-4min with 1.5min RBI at 92-100% FTP. I also like longer efforts of 8-15min at 80-85%FTP. These are especially specific to gravel events where you want a strong finish in the last 5-10 miles. Another way to build your fatigue resistance and stamina is to do back to back days of intervals. IE Tuesday do some Sweet spot efforts at 88-93% FTP and then on Wednesday do some solid tempo efforts at 80% of FTP, I call this adding some density to your trianing.
Hope this helps and happy training.


Thanks Coach Pike - this is very helpful!

I think one thing to consider is pros vs amateurs. A 3 hour zone 2 ride for a Pro may be a relatively easy ride for them whereas for an amateur it may be a potent stimulus.

If a Pro is riding 15-20 hours per week then every ride is going to be 2-5+ hours in length. So you have to consider whether a pro is throwing in extra threshold efforts in their 3+ hour endurance rides or if those efforts are actually part of their weekly planned intensity distribution. I think it would be the later.


I do use this type of training quite a bit, but I would often incorporate a build within the session, something like this;

40m endurance / 20m tempo
30m endurance / 30m tempo
40m endurance / 20m threshold

If you find you can’t maintain the tempo and threshold efforts inside the long ride, then slow down the endurance piece. This is likely due to the amount of carbs being used at your endurance pace, taking fuel away from the harder efforts you are trying to do.


Thanks coach. This looks like an excellent (albeit difficult) workout. And I think your explanation of why it was hard to maintain the threshold effort sounds right on the money!

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As I understand it, these are different progressions, and not a single ride.

40 End/20 Tempo/40 End/20 Tempo…
You alternate the intervals throughout the ride.

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Ah thank you. That makes sense. That as a single ride seemed like it would be a kick in the bibs, but actually not that different from my races.

that is an example of a single ride, there would be a progression before that of:

getting to 3h endurance with power and heart rate in the zone.

Then I would add tempo to the ride.

Then I would add some tempo and threshold to the ride.

Eventually, I might even add max efforts 5m long at the beginning and end.

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note my response to @shawnfife there would be a progression to get you there, but if you are riding for 3 hours already and trying to add threshold and aren’t able to complete, then try some combination of what I have above that you can handle at the moment and progress.

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Yes thank you. This looks like a great workout for me to build up to. I’m transitioning from base to build phase this month and this looks great to start working up to. I’m already doing 2 x 22 min threshold workouts, 3 x 30 tempo rides, and 4-5 hours zone 2 long rides separately, so I think I am ready to start adding the tempo to a long Zone 2 ride and go from there. I suppose I will call this one of two intensity sessions per week for purposes of training stress.


Hey so I started to do something similar in my trainings. In an effort to add more Z2 in my weeks, on interval days, I add 30-40min Z2 before the intervals, and then 20-30min at the end. Right now my intervals are threshold intervals, so I guess it’s very much related to this topic. However, I’ve heard Dr. Iñigo San-Millán say on Peter Attia’s podcast (201 - Deep dive back into Zone 2 Training | Iñigo San-Millán, Ph.D. & Peter Attia, M.D. - YouTube - timestamp: 2:17:30), that doing Z2 before intervals is great, because you can get all the benefits from Z2 training, and then get the benefits of the intervals after. But doing the intervals at the beginning or middle of the ride, and you lose (some of?) the Z2 benefits. Because post-intervals, you might be riding at Z2 power, but your physiological state is not the same anymore. You’re not recruiting the oxydative/mitochondrial system as well (increased blood lactate levels inhibiting lipolysis, decreasing activity of cpt-1/cpt-2 which interferes with the transport of fatty acids, etc.).
His statement made me reconsider adding Z2 at the end of my interval workouts, and putting it all at the beginning. While I like this format and think that developing the ability to put in hard efforts at the end of rides/races is important. I also wonder, if always doing intervals after Z2 riding, might sometimes prevent me from hitting top quality intervals, as I would never be 100% fresh for those intervals. Any thoughts? Am I overthinking this lol? thanks!

I would think that adding Zone 2 to intervals, whether at the beginning or end, would be good training, but it might be training different things. If you put it first, you are probably getting the benefits of the Zone 2, and the psychological training of then doing threshold work on top of that Zone 2 work. You could probably just test whether or not it keeps you from hitting your threshold target through trial and error. If you put the Z2 after the intervals, then you’d presumably be training your ability (physically and mentally) to recover from a hard effort and continue after. For the types of races I do (usually 3-6 hour gravel with a lot of hard efforts) these both seem relevant, so I plan to do both styles. My two cents as a non-expert.


With intervals you work on your Type II fibers and the associated energy system, without putting the Type I’s and the aerobic system to rest. In between the intervals you can take rest (for a quick recharge) or continue in zone 1 or 2 (heart rate zones!) to keep the aerobic system going.

Intervals with HR z1/z2 in between intervals is very efficient because you will produce a relative high volume, which is the key performance variable. yes, it will take a bit longer to recharge, but with the benefit of volume.

My main feedback would be to focus on HR instead of power zones, because:

  • when your type II fibers are done for the day, you will ask too much power of your type I’s, which they cannot deliver. Your zones data will be way off, you will be overasking your body, injuries are imminent.
    To my experience HR will help you out here.
    Going by feel is another great way: the in-between-interval-feel should be a low RPE or ‘tail-wind coasting feeling’.

If you do your easy stuff before the intervals, you are easily going to fast. If you them afterwords, you are pretty certain you are training Type I’s (because the II’s are toasted).
In between is fine, just mind the intensity as described above. If you went to fast, you cannot easily accelerate in the interval (you’ll know when you experience it).

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I think it depends on how you definite “benefit” from a Z2 ride, like others have said in this thread. Using the metrics that ISM is stating in your quote as your measure of benefit, then yes, intervals only at the end. But if you want to work on recovering from hard efforts, having Z2 after intervals should help your system improve recovery from hard efforts whilst keeping the pedals turning, as in a race situation. I know my body takes about 30-40mins of Z2 riding to return to “normal” after a really hard interval set. I’d like to reduce that.

Also spoken from a non expert. I am keen to hear more views on this topic.