Above: the “Flying Frenchman” Yohann Coppel expresses his love for training zone 4 (threshold)


Don’t Just “Know” Your Triathlon Training Zones– Understand Them!

I’m writing this post as part of a series of resources for the team I call “executing your plan.”   I have way too many people I coach who:

* go a little too hard on their “low stress days”,  causing them to stagnate

* reschedule workouts in ways that are destructive because they don’t want to “miss a workout”  (e.g. they’ll put their 2 hardest runs back to back because they missed one of them).

* and otherwise make a mess of their training by making poor decisions.


Executing your plan doesn’t mean just following your plan blindly.  It means making smart decisions as you go through your week and your workouts.    Part of making good decisions is understanding your training intensities (not just memorizing your zones).   If you know the purpose of each intensity level then you can make better decisions when executing your plan.








Saurabh shows us his favorite zone.  Understand your zones, don’t just memorize them.   




3 Keys for Understanding Your Training Zones

Zones Are a "General Area" Not an Exact Level!

Never kill yourself to hit a certain target or worry about being perfect (except to not go too hard in easy days).   We train in a general area to get certain adaptations (positive effects) while trying to avoid negative effects (fatigue, injury).   It doesn’t have to be complex.   Zones “meld” into one another-- being 2% below the planned zone because you are tired is fine.   

The Importance of Low Stress Workout Days (heart rate caps on easy days)

Training below your aerobic threshold (roughly 30 beats below your ANaerobic threshold) at an intensity that feels relatively easy is a "low stress" training day.   Going just a bit harder to Ironman effort will cause the body to have a stress response-- don't go there!   These low stress workouts give our bodies and systems a well needed rest so we don't become chronically overstressed (which means our bodies won't adapt and improve).  But don't be fooled-- these low heart rate endurance workouts have big benefits.  


A Little Too Easy is Much Better Than a Little Too Hard

Going too hard can lead to injury, sickness and deep fatigue (or stagnation).  Going a little too easy... probably won't affect your performance at all in the long run.    Stay healthy and strong: (1) keep those "low stress" workouts easy;  (2) rarely exceed your intensity limits in hard workouts (especially for the run) and (3) if you are showing signs of being overstressed (signs of tissue overload, being run down, excessively fatigued)-- back off and go easier.   In other words, we we much more about staying below the top of the zone as oppposed to staying above the bottom of the zone.

Triathlon Training Zones Simplified?  A 3 Zone Model.   


 Really, for training purposes we could easily slice our training into just 3 zones and I think it’s helpful to think of zones this way (especially realizing that we don’t want “easy” workouts to accidentally become “medium” workouts.    

A common pattern among athletes who don’t improve is to make their easy workouts medium.  That makes them too tired for their hard workouts, so those workouts become medium as well.   So they are constantly training at a mediocre medium level.  Don’t fall into that trap!  Go easy on easy days and hard on hard days!

Zone A:  Easy (≈30-69%)

Easy should (a) feel easy AND (b) be below your aerobic threshold HR (roughly 30 beats below your anaerobic threshold HR).  The beauty of this intensity is that we can do a massive amount of it because it’s low stress.  We can train here and get solid endurance benefits while giving our bodies a break from stress so we can recover.  (the best of both worlds!)  THIS AREA IS KEY!   DO NOT TURN YOUR EASY / RELAXED WORKOUTS INTO “MEDIUM” WORKOUTS JUST BECAUSE YOU FEEL GOOD.


Zone B:  Medium (≈70-90+%)


This is where you have the foot on the gas a bit (harder than easy), but you are not pushing your limits.   Ironman effort, HIM effort or maybe short reps at olympic distance effort are around here.   Even though it doesn’t really feel that hard, it’s STRESSFUL.  This is sometimes called the “gray zone” because it’s hard enough to be stressful, but it’s not as potent as going “hard” for making you fast.    We don’t do much here in the “get fast” portion of our training, but we do a large amount of training here as we get closer to our races, since this is our race intensity.   This intensity is good for building “stamina” to go the distance at a solid race effort.

Zone C: Hard – close to your limit!

Some people define this level as being above your anaerobic threshold, but for our purposes let’s just say you are going “hard” when you are close to your limits / uncomfortable.   (If you are racing an olympic distance  or doing a 90 min climb at 90% and feeling pretty darn uncomfortable, we’ll call that hard.  For “hard” training, you don’t have to kill yourself– a “solid hard effort” is good enough.    In the offseason we like to spend most of our time going hard or easy, without as much “medium” mixed in.

Whether you call it “easy” “relaxed” “zone A” “zone 1” or “zone 2a”– those easier days are perfect for enjoying scenery and snapping the occasional selfie.

Slicing it More Thinly– All Your Zones

Understanding the 3 zone model above is key just so you understand the basic idea.  But sometimes we want to slice and dice our training more thinly.    Without further ado… here are your TriForce training zones.  (your zones spreadsheet will have the details for you).

Zone 1:  Recovery  (≈30-50%)  “Zero Stress” Zone.

This is VERY easy– not a workout at all.  Just moving blood around to help speed recovery, prevent stiffening up, and promote healing.  Avoid pushing these just a bit harder to try to get a workout.  We want ZERO workout!  E.g. a recovery run should be more like a walk than a run.  I might run low 7s for my Ironman pace and my “recovery” pace can be closer to 12 minutes per mile.  In the swim this is just “flopping” in the water probably with a pull buoy.

Zone 2a: (≈ 55-69%) (below your aerobic threshold HR)

“Easy Endurance.”  “Relaxed.”   “Low Stress” Endurance.

This is just hard enough you are getting endurance benefits, but it’s more of an “all day” relaxed effort.  You should never “try to go faster or harder” when training at this level.  Set your heart rate monitor to beep at 30 beats below threshold HR and try to never hear the beep!   This is a LOW STRESS endurance day to allow our bodies to recharge our batteries.  Pushing harder (more like IM effort) turns it into a STRESSFUL day which is exactly what we do NOT want.  Whatever your body settles into is fine (even if it is a very low power / slow pace).  Never “push for” a certain pace or power. These workouts are in the plan to give you endurance benefits but to be very easy on the body so you recover from previous workouts and feel good for your upcoming workouts.  In the swim this might be 15 seconds or more slower than your 1000 tt pace.   It’s an “all day” relaxed effort.

Zone 2b: (≈ 70-78%) (Ironman-ish) Steady / Moderate Endurance

This is general endurance work- solid long ride/ long run effort.   Training at this level creates a stress response in the body even though it doesn’t feel that hard.  (That’s why we create a separate zone for this training as opposed to lumping it in with zone 2a).  So if you are supposed to do a “relaxed” workout, don’t creep into this zone.    The foot is on the gas just a little bit, but you are comfortable and never pushing to go harder / having to try to go harder (except maybe at the end of a long workout).  On a good day you might naturally settle into Ironman effort or slightly higher, but we almost never TARGET a certain effort for long workouts unless we are testing our Ironman pacing.  Just settle into what feels right today (even if it’s a very slow pace or low power).  Pushing long workouts on tired legs is a major cause of deep fatigue.  Always feel free to go “relaxed” in these workouts if the legs are tired.  Fatigue should happen from how long the workout is, not from how hard you are pushing.  In the swim this could be anywhere from 6-10 seconds per 100 slower than your 1000 tt pace.

Zone 3a: (≈ 78-87%) (Half Ironman-ish) Medium Endurance.

The foot is on the gas now, but this is still a long distance effort that you can hold for 2+ hours (or maybe 30-60 min in the swim).  About half ironman effort or open marathon running effort.   When you start to feel a “little bit of burn” in the legs you know you are probably starting to to hit the upper end of this level.  Speaking of which…

Zone 3b (or 4a?): (≈ 88-94%) (Olympic Distance-ish) “Sweet Spot” 

This is where you start to feel just that little bit of lactate burn in the legs.  On a good day this is the top of zone 3ish.  When you are tired it might kick in earlier.  We like doing intervals here because it’s hard enough to get good adaptations (and you can do quite a large amount of work here compared to going harder), but you can recover quickly compared to harder intensities.    You feel a hint of lactate but you aren’t “pushing into the burn” like in the next level.  It’s called the “sweet spot” because it’s hard enough to create big adaptations but easy enough that you can do large amounts of it without deeply fatiguing.  We like this early in the year to start to get our bodies used to going harder and late in our IM / HIM build to maintain threshold power when are legs might be too tired to push harder.

Zone 4 – Threshold  (≈ 94-104%) (Sprint Distance-ish)

This is hard but sustainable for 30+minutes.  (100% is around what you can hold for 1 hour).    You are feeling lactate and pushing it right up to the limit of what is sustainable for an extended period of time.  You get the sense that if you pushed any harder you will hit the wall pretty quickly.   Experienced athletes don’t really need testing to understand where this level lies.  Your body will react to this level in a clear way, especially if you go above your threshold.  

Zone 5 – Vo2 Max  (≈ 105-125%) (Hard!  Maybe about what you can hold for 6 min.)

This is an effort you can hold for maybe 6 minutes.  This is the effort that will take you to the max you can do aerobically. Going any harder will require the power to come from your anaerobic system.    Most of the time we do vo2 max work as short intervals (30 seconds to 4 minutes) with long rest.

“Hard” = Uncomfortable.  Close to Your Best Effort.  Not a zone– see what you can do!

When you are told to go hard, that means see what you can do.  Don’t try for a certain power or pace– instead, go by feel.  Learn to know your body’s limits.   “Hard” means around the best you can sustain.   A hard 20 minute finish to a run, e.g.,  should be very uncomfortable by the end, with you very eager for the rep to end.  For hard reps (e.g. 5 * 3 min hard), go at around the best effort you can hold across all 5 reps (so don’t kill yourself on #1).    Exactly how fast / how hard you go depends on the workout.  Obviously, 10 x 30 seconds hard on the bike will be at a much higher power level then doing 1 hour hard at the end of a 3 hour bike ride.  Go by feel for these!   This is how you learn your limits and how to pace well.   You don’t always have to max out your mental intensity for these.  “Just do” these reps.  Don’t think too much about them.   To quote Brett Sutton- “Hard is hard!”  Don’t worry if you are going hard enough or about power numbers, etc.


Knowledge is power!   If you know WHY we train at certain intensities it increases your chances of making smart decisions through your training build.   Remember, DOING your plan isn’t the goal.  It’s EXECUTING your plan to get the best results!