CyclingVO2maxIntermediate 53 min

VO₂max intervals: 4 × 5 min on the bike

4x5 VO2max intervals: four 5-minute efforts at 106–115% of FTP, with 2 min 30 of recovery between each. 20 minutes of work in a 52-minute session. The reference long format for VO₂max, useful for climbs of a few minutes and sustained attacks.

Written by Pierre Halloo · Updated 25 October 2026

Session profile11 blocks

At a glance

Duration: 53 min
Main target: 106–115%FTP5 Z5 · VO2 Max
Time at target: 20 min
Estimated load: 58
Structure: 4 × 5′ at 106–115% FTP, 2′30 recovery
Level: Intermediate
Equipment: Power meter · Smart trainer

The session in detail

FTP

Time in zone

Z123 min
Z210 min
Z520 min

What the targets mean

The session's targets, in watts for three reference FTPs
Target	Zone	Time	FTP 200 W	FTP 250 W	FTP 300 W
106–115%	5VO2 Max	20 min	212–230 W	265–288 W	318–345 W
50–60%	1Recovery	8 min	100–120 W	125–150 W	150–180 W

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What this session is for

Four by five builds your VO₂max and maximal aerobic power through long, continuous efforts. Five minutes is long enough for your oxygen uptake to reach its peak and stay there for several minutes; 2 min 30 of recovery is short enough that you don't lose it all before the next effort. That 2-to-1 work-to-rest ratio is the one a self-paced study linked with more relative time near VO₂max than a 4-to-1 ratio.

It's also the comparison format in Rønnestad's studies, where 30/15s beat it on VO₂max. Four by five is still an effective format, simpler to ride, and closer to the effort of a climb lasting a few minutes.

Who it's for

Intermediate to advanced riders who've already done shorter VO₂max efforts, such as the Norwegian 4 × 4. It suits climbers above all, and riders preparing for races where the attacks come on 3- to 6-minute climbs. You need a recently measured FTP.

When to do it

One or two VO₂max sessions a week is a common guideline, with at least one easy day between hard sessions. Avoid the day before a long ride or a race. To progress, go from 4 to 5 efforts, or towards Lindsay's longer, slightly less intense protocol, then Seiler's 4 × 8 min.

How to do it

Warm-up
15 min
5′ at 45–55% FTP + 5′ at 56–65% FTP + 5′ at 66–75% FTP
15 minutes building from 45 to 75% of FTP, in 5-minute steps. Five-minute efforts go better on properly warm legs: don't cut the warm-up short.
Main set
28 min
4 × 5′ at 106–115% FTP, 2′30 recovery
Four 5-minute efforts at 106–115% of FTP, or 265 to 288 W for an FTP of 250 W, with 2 min 30 at 50–60% between them, or 125 to 150 W. Pick a power you can repeat four times: in Rønnestad's studies, it's the highest power you can hold across all four efforts, not a value fixed in advance. ERG mode works well here: the changes are few, and it stops you creeping above the target.
Cool-down
10 min
10′ at 40–55% FTP
10 very easy minutes at 40–55% of FTP. Then the check: if your power dropped by more than 5% on the last effort, the target was too high, so lower it next time; if the last effort matched the first, go up a little.

How it should feel

The first minute of each effort feels manageable, the third starts to burn, and the last has your legs and lungs maxed out. The 2 min 30 recovery is enough to go again, not enough to feel fresh. Guide: 9 out of 10 at the end of each effort.

Common mistakes

Aiming for the top of the range on effort one

The first effort, on fresh legs, feels easy at 115%. The fourth, much less so. Start at the bottom of the range and keep the margin for the last one.

Ignoring the power drop

If your last effort comes out more than 5% below the first, the session has turned into survival. That's not failure, it's information: lower the target next time.

Stretching the recovery

2 min 30 is short, on purpose: the 2-to-1 ratio keeps your oxygen uptake high enough for the next effort to reach it quickly. If you need more, lower the power rather than lengthening the break.

Mistaking it for long threshold work

At 106–115% of FTP you're above threshold: five minutes, not twenty. It isn't an extended threshold session but VO₂max work.

When to skip it

Before you start

A recently measured FTP.
Some shorter VO₂max efforts already behind you.

Skip it if

You're very tired, or a long ride or race is planned for the next day.
You have doubts about your health: get medical advice before near-maximal efforts.

Origin and evidence

Level of evidence

Good evidenceLevel 4 of 5

This is the 'long intervals' format from the studies by Rønnestad and colleagues (Scand J Med Sci Sports 2015 and 2020), where it served as the comparison for 30/15s: in both studies, 30/15s gave better results on VO₂max and maximal aerobic power; 4 × 5 minutes remains an effective and widely used format. In those studies the efforts are ridden at the hardest sustainable effort; recovery at about half the effort power comes from a secondary analysis. A self-paced study showed more relative time near VO₂max with a 2-to-1 work-to-rest ratio than with 4 to 1. Lindsay and colleagues (Med Sci Sports Exerc 1996): 6 to 8 × 5 minutes at 80% of maximal aerobic power, with 60 seconds of recovery, improved 40 km time-trial performance in 4 weeks. The 106–115% range, the 5% rule, the warm-up and the cool-down are Wattson choices. Bottom line: good evidence.

Sources

Rønnestad B. R. et al., Scand J Med Sci Sports 2015
Rønnestad B. R. et al., Scand J Med Sci Sports 2020
Lindsay F. H. et al., Med Sci Sports Exerc 1996

Frequently asked questions

What power should I ride 4x5 VO2max intervals at?

At 106–115% of FTP: 212 to 230 W for an FTP of 200 W, 265 to 288 W for 250 W, 318 to 345 W for 300 W, with recoveries at 50–60%. The real marker is the highest power you can repeat over all four efforts, without dropping more than 5% on the last.

4 × 5 minutes or 30/15s: which should I choose?

In Rønnestad's studies, 30/15s raised VO₂max more. Four by five is still effective, simpler to ride, and closer to a climb of a few minutes. The two complement each other: alternate them over a block, or choose according to the terrain you race on.

4 × 5 minutes or the Norwegian 4 × 4?

The Norwegian 4 × 4 is shorter per effort, with a longer recovery: a good starting point. Four by five builds more work, 20 minutes against 16, with a shorter recovery. Move to the second once the first goes by without difficulty.

How much recovery between 5-minute efforts?

Here, 2 min 30, half the effort. That 2-to-1 ratio keeps your oxygen uptake high enough between reps. Lindsay's protocol goes further, with just 60 seconds, but at a slightly lower intensity.

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