HomeBlogThreshold Heart Rate – A Cyclists Magic Number

Threshold Heart Rate – A Cyclists Magic Number

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What if I told you YOU had a magic number?

A number that made you place better in races?

A number that made you break all your own STRAVA records?

A number that defined your optimal performance?

Well that number exists, and you are only a 20 minute ride away from finding it out!

This number is more commonly known as your THRESHOLD HEART RATE

In the simplest non scientific form I’m going to try and explain what this threshold heart rate is…

THRESHOLD HEART RATE is the heart rate at which your body can no longer clear out the lactate you are producing quick enough, basically causing your performance to drop significantly.

In other words…


I like to picture a small boat with a hole in it. The water coming in is being bucketed out as quick as possible by the people in the boat. But there is a limit to how quickly they can bucket out the water. There comes a tipping point where the amount of water entering the boat is too much for the bucketeers and the boat begins to fill up with water to the point where it sinks.

Your threshold heart rate is that point where your body can no longer bucket out all the lactate you are producing.


How do I find my magic number?

I’m glad you asked, it’s dead easy…

All you need is a heart rate monitor and bike computer (standard kit these days). You will need a preferably flat or inclined course that allows you to ride hard for a full 30mins without having to stop, rest, brake, freewheel or change your pace too often.

What you need to do after a warmup is complete a 30min INDIVIDUAL time trial. This must be done by yourself and does not require aero kit. This is about testing YOUR engine for 30mins to see what happens.

For the entire 30mins you must race as hard as you can. Do not look at your HR as this is insignificant at this point and may have an affect on your results.

Once you have finished, be sure to do a cool down and go home and upload your data.

You now need to find the AVERAGE HEART RATE of the LAST 20 MINUTES of your time trial.

If you are not sure how to do this, simply hit your LAP button 10mins into the time trial and then hit it again at the 30min mark (the end of the effort). This will give you the average HR for that LAP.


What do I do with my magic number now?

Now you have your threshold HR, we can quickly calculate your other ZONES. These zones are simple brackets of heart rates that when training in them, have different effects on the body and performance. These Zones are as follows:

Zone 1- Less than 85% of your magic number

Zone2- 85% to 89% of your magic number

Zone3-  90% to 94% of your magic number

Zone4- 95% to 99% of your magic number

Zone5a- 100% to 102% of your magic number

Zone5b- 103% to 106% of your magic number

Zone5c- More than 106% of your magic number

Once you have calculated these, most modern bike computers allow you to enter your zone ranges so now you can train and race by zones.


It takes a long time to raise a sunken boat…

Have you ever been in a race or trying to set a hot time up a climb, and you go DEEP into the red zone? Once you are there it feels like you just can’t recover and you suffer all the way through the effort.

This is because once you ‘overheat’, your performance drops and it takes a significant amount of time to recover before you can start laying the power down again. By then your opponent has vanished into the distance and you’re struggling to stay balanced on your bike let alone breathe.

The best thing you can do is avoid going deep into the red.

Avoid sinking the boat

Most of the time, backing off the pace momentarily to stop your HR from soaring past your magic number will have you back on race pace FAR QUICKER than if you bury yourself and blow up. Trying to raise the boat from the depths is always going to take longer than stemming the flow momentarily to let your bucketeers catch up.


What about MAX HR?

What about it?

It really is a useless number. Especially in terms of cycle racing and training.

It’s a number determined by many genetic variables and is a very inaccurate method of determining effective training zones. THRESHOLD HR really is the magic number…


Get out and find your number

If you haven’t already calculated your magic number get out there and do it! Get it over with.

Sure it’s 30mins of pain, but you will then be set up and ready to take your riding to the next level.

Don’t forget to revisit some of your favorite STRAVA segments when you’ve worked it out…

You might be surprised 😉


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