In this post I’ll discuss how to train in Zone 6, otherwise known as the “Anaerobic Capacity Zone”.

We’ll look at how intense this training zone is, what’s its purpose and an example workout that you can use to train this aspect of your cycling fitness.

Zone 6 equates to approximately 121-150% of function threshold power.

So, as you can probably tell, this is a very high level of intensity that requires a lot of mental and physical perseverance.

It’s typically known as the anaerobic capacity zone, and requires you to exercise at a level far beyond your lactate threshold, i.e. an intensity that produces a high amount of lactic acid in the working muscles, due to the rapid burning of glycogen.

Zone 6 is typically executed as short interval training, where these intervals can last anywhere between 20 and 90 seconds, with recovery intervals lasting around twice to over three or four times as long as the work interval.

The intensity is very similar to what would be experienced in events like a cycling road race on a short, sharp climb, or the effort from one corner to the next in a criterium.


Training in Zone 6 has several purposes…

The first of these is to increase the time at which the athlete can exercise in an anaerobic state, which means working at an intensity where the body cannot meet its demands for oxygen.

In essence, this type of training increases the capacity to accelerate to speeds far beyond the lactate threshold, which is important in a race environment.

Secondly, training in Zone 6 not only facilitates the building of the athlete’s anaerobic engine, but also improves the athlete’s ability to recover from such an effort and repeat it again and again.

This is an especially useful skill for any type of competitive cyclist to have, as changes in pace in a race are sudden, often unexpected and occur more than once.

By conducting this type of training consistently, you should see big reductions in the time it takes them to recover between short, sharp intervals.

You might like this post on when to schedule your interval training in a ride.


When executing this type of training, you’ll need to rely on their power meter or intuitive pacing, since the intervals are just too short for heart rate to give any kind of accurate indication of intensity.

It’s very easy to perform the first intervals in an anaerobic capacity workout too intensely, and later fail to hit the required output in the final few intervals.

It’s always advised to try to speed up as you progress through such a workout, applying intelligent pacing in the earlier stages to ensure you don’t fail before the end of the set.

As an example, a Zone 6 workout might look like:

  • 30mins of Zone 2
  • 6-8x 1minute @ Zone 6 with a 3-min active recovery interval between each repetition
  • 30-45 minutes of Zone 2 after this main set

Be very careful not to do too much of this type of training, since it’s incredibly stressful on the body and can reduce your training capacity greatly.

It’s therefore best used in the few weeks leading up to a target event, where other aspects of fitness like your anaerobic threshold and VO2Max should precede it.

Get in touch if you need any guidance on incorporating Zone 6 into your training plan by using the contact form here.