Announcing "Endurance in Zone" for Garmin devices

Have you ever noticed that TrainerRoad endurance workouts tend to be much simpler in structure outdoors than indoors? Look at Rymsza, for example. It’s got 33 stages! But that’s indoors. The outdoor version simply says “Settle into 155 minutes between 161-181 watts,” plus a little warm-up and cool-down.

I think I know why TrainerRoad is doing it like this. It’s really challenging to follow a structured workout when you’re riding outdoors. For one thing, traffic and other road obstacles will play a part. But unless you have endless flats, or really long climbs, the rolling hills will make it difficult to stay at the prescribed power levels.

The TrainerRoad folks are quick to point out, and rightly so, that it is easier to do a high quality workout indoors. Outdoor rides simply involve so much coasting. So my guess is that they somewhat reluctantly added outdoor versions of their workouts, but they kind of had to, because for most people there is more to cycling than staying inside sweating on a trainer.

But how do you do those long endurance workouts outdoors? Even something as simple as staying between 161-181 watts for 155 minutes can be hard to manage. What do you do when a long descent comes up, and your average power drops like a stone? Do you compensate by going harder later? You can, but you aren’t really doing the prescribed workout then. Do you pause the computer on descents? Surely not.

This is why I made “Endurance in Zone.” It allows you to configure 1-3 target zones and durations, and keeps track of how much time you have spent above target power (or heart rate).

For the example above, you may simply configure that you need to do 155 minutes above 161 watts. But with this nice tool, you don’t have to simplify the workout as much as this. You can look at the indoor Rymsza workout and find out that it involves 50 minutes above 175 watts, as well as 157 minutes (in total) above 161 watts. Configure these two zones and let the app take care of the rest.

The “app” is actually a data field on Garmin devices. It is designed so that it works on a small space shared with many other data fields, but it displays more data, possibly with a bigger font, if you give it more space. It works on Garmin watches as well. It shows a green background when you are meeting your target (based on a 30 second average), and red when you’re not.

Configuring the zones is easily done using Garmin Connect on your mobile phone, and you can certainly do this before each outdoor ride.

The app can be found here:

If you come up with any improvement suggestions or feature ideas, I’d love to hear them!

Garmin Forerunner 945



Could it be used as a target for race pacing. Say I want to be sitting above 250W almost the entire time, but trying to stay below say 290W most of the time. Could I have a big green square on my display (or red if I’m straying)?


Yup, coach Chad has mentioned that many of the steps and target changes in the longer inside Endurance rides are for variety, not some marginal or hidden training benefit. They ditch them for the outside workouts since there is already more inherent variability in that use case.


I pick endurance rides with shorter “intervals” just because I don’t want to see 20min+ left in an interval. I don’t care if it changes by 1 watt or 10.

You should all come live in the plains like me… It’s pretty easy to never see a hill or a stop light or sign. You can stay in whatever zone you like. Unless the wind picks up then you’ll be zone 5 in one direction and struggling to spin fast enough to even hit zone 2 in the other direction.

Neat idea for an app though. But I do fine just having the field for my power and/or HR zone on the screen is simple enough.


@redlude97 and @mcneese.chad: Yes, I’m sure you’re right that an endurance workout doesn’t really need 33 stages! But even if you just want to do “155 minutes above 161 watts,” it’s still nice to be able to tell how well you are fulfilling that goal.

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unless it is a workout targeting cadence training - Baxter being prime example.

Sure, but we are talking about power targets here, not “drills”… which are different kettle of fish. Connecting drills to steps is also done, and can largely be discarded for the same reason since they are not practical in the same way outside (although they can still be done in some cases).


The app doesn’t actually operate with any upper limit for zones, because there’s no reason not to credit somebody with their time spent on endurance training just because they went a little harder than prescribed. But I agree it might be interesting to add that feature for the reason you mention.

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You would have hated seeing 3 hours and 20 minutes on my Garmin this past weekend



This ^^^^^ 100%

I dont live in the plains but the relatively flat rolling bump of east England. As with a lot of my outside endurance workouts I chose this to break it up.

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That’s actually another aspect of the app that I find helpful. Rather than looking at an interval of 20 minutes or more, you’re looking at a percentage of workout done. You’re free to take a break whenever you feel you need to, then get back in the zone later. I feel this adds that little bit of something to focus on during a long ride.

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Nope, you’re not allowed. Not “Endurance” :stuck_out_tongue_winking_eye:

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Agree. It’s all endurance :grin::upside_down_face:


I’ve lived in a couple cities that are pan flat and for outside structured workouts they were perfect. I loved it. Sure I missed some variety but it was so easy to hit my power targets.

Now I live somewhere and it’s all hills. It’s a challenge to get the power targets outside for a workout. I’m always looking for some mild climb that’s long enough for the interval I’m doing


That sounds pretty tough! Good luck :muscle:

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This could be pretty neat, although I do think having a bracketed range could be nice. For example if you are targeting 150min of endurance - a 4 minute VO2 effort on a segment is a bit of a different stressor/benefit. Having a bracketed range is useful for keeping yourself honest staying in range.

I use TIZ fields on a Garmin page for Z2,3,4 when doing longer outdoor rides, but having the bar and % is kind of cool.

Can it be configured for HR as well?

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Yes, you can choose to target power or heart rate.

I haven’t included an upper zone limit because if 4 out of your 150 minutes were at VO2, I’d say you would still have achieved your workout goal - and then some.

I should mention that the app doesn’t do everything for you. You still need to try to keep a steady pace, and make your work segments as long as you can. The app will allow you to do 1 minute on and off for 300 minutes, but you would be cheating yourself if you did that :laughing:

I actually think the indoor workout has so many stages because endurance indoors is boring. Outdoors you have the scenery, the rolling landscape, the weather, the roads , the bends, the wild life, constant changing stimulus. You don’t need stimulation or variety via 33 stages of what not.

I always treat endurance rides as having an intensity cap. There’s an intensity I want to stay below even up hills. If a downhill isn’t suitable for maintaining your target zone you drop into Z1. You don’t try and hit an average power you just try your best to keep it in your Z2 range for the duration you’re able to get out for. If you drop below it for a bit, it’s no big deal.

If I’m due a 2 hour outdoor endurance ride I’ll pick a suitable loop. It may be 1 hour 55 mins, it may be 2 hours 17 mins. It’s really doesn’t matter and doesn’t have to be precise as long as I’ve done my best to stay in zone and avoided going hard.


I’m with you. These endurance rides are a perfect use case for TSS and building or maintaining low aerobic (base) fitness. I’ve seen the science, there are no magic minutes at certain intensities for endurance work.

Ride steady, don’t worry about briefly going over or under, and ride until you hit your TSS target. Slowly push up CTL. It still works. Keep it simple.


Sure, you can certainly do endurance training that way and get good benefits as well as beautiful rides. I’ve done it myself for several years.

But if, on the other hand, you are intrigued by the TR Workout Levels, and would like to advance in them, you’d better do it progressively and work your way up. Doing an endurance ride at 200 watts is no problem for the first hour. After 5-6 hours it’s a different ball game. A level 9 TR endurance ride is only about 5 hours. Riding outdoors for 5 hours is easy. But doing it while completing a level 9 workout is anything but!