Attacking the first minute
Your heart rate lags: the first minute feels easy, and the temptation is to push harder. The result is a third effort that falls apart. Set your power from the start and let your heart catch up.
CyclingVO2maxIntermediate 50 min
Norwegian 4 × 4 on the bike
The Norwegian 4x4 for cycling: four 4-minute efforts at 106–118% of FTP, with 3 minutes of active recovery between each. 16 minutes of work in a 50-minute session. A format studied extensively in running, carried over to the bike here and checked by heart rate.
Session profile11 blocks
At a glance
- Duration
- 50 min
- Main target
- 106–118%FTP5 Z5 · VO2 Max
- Time at target
- 16 min
- Estimated load
- 52
- Structure
- 4 × 4′ at 106–118% FTP, 3′ recovery
- Level
- Intermediate
- Equipment
- Power meter · Heart rate monitor
The session in detail
FTP
Time in zone
- Z115 min
- Z219 min
- Z516 min
What the targets mean
| Target | Zone | Time | FTP 200 W | FTP 250 W | FTP 300 W |
|---|---|---|---|---|---|
| 106–118% | 5VO2 Max | 16 min | 212–236 W | 265–295 W | 318–354 W |
| 55–65% | 2Endurance | 9 min | 110–130 W | 138–163 W | 165–195 W |
Put this session on your bike computer or watch
Wattson works out the targets from your FTP and sends the session to your Garmin, Wahoo, Coros or Suunto.
What this session is for
The 4 × 4 targets your VO₂max, the maximum amount of oxygen your body can use. Four minutes is long enough to bring your heart and breathing close to their maximum and keep them there for a while; three easy minutes are enough to repeat the effort four times at the same power.
The protocol comes from Jan Helgerud's group in Norway, who tested it in running. Over 8 weeks it raised VO₂max more than long endurance riding or threshold work, for the same total work. Nobody has tested it as such on a bike: the session rests on the reasonable, but unverified, idea that the same cardiac stimulus has the same effect in the saddle.
Who it's for
Healthy intermediate to advanced riders who know their FTP and want a VO₂max session that's easy to remember. A heart rate strap is very useful: the original protocol is set by heart rate, and it's what tells you whether your power is right. If efforts above threshold are new to you, start with something shorter, such as 30/30s on the bike.
When to do it
One or two VO₂max sessions a week is a common guideline, with 48 hours before another hard session. In Helgerud's study, participants did three a week for 8 weeks, but that was a study protocol. Avoid the day before a long ride or a race. To progress, move on to 5-minute intervals, then Seiler's 4 × 8 min.
How to do it
Warm-up
15 min5′ 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. If you're on the turbo, switch the fan on before the first effort: on this session it is not a comfort item.
Main set
25 min4 × 4′ at 106–118% FTP, 3′ recovery
Four 4-minute efforts at 106–118% of FTP, or 265 to 295 W for an FTP of 250 W, with 3 minutes at 55–65% between them, or 138 to 163 W. Start at the bottom of the range: the power is there straight away, but your heart takes a good two minutes to climb, and the first minute feels too easy. By the end of each effort, your heart rate should reach 90 to 95% of its maximum. All four efforts are held at the same power.
Cool-down
10 min10′ at 40–55% FTP
10 very easy minutes at 40–55% of FTP. If your heart rate never got above 90% of maximum, your power was too low; if you couldn't finish the fourth effort, it was too high. Adjust within the range next time.
How it should feel
Very hard. The first minute is deceptive, then your breathing runs away and by the end of each effort talking is out of the question. The three minutes of recovery fly by, and the fourth effort is ridden on willpower. Guide: 9 out of 10 at the end of each effort.
Common mistakes
Trusting the watts alone
The 106–118% range is an approximate translation of a protocol set by heart rate. Depending on your profile, it may be a little high or low for you. Your heart rate at the end of each effort, 90 to 95% of maximum, is the check that matters.
Confusing it with Seiler's 4 × 4
Stephen Seiler's 4 × 4 is ridden at maximal effort with 2 minutes of recovery. Same name, different intensity and recovery: don't mix the two in one session.
Riding without airflow
On the turbo, heat pushes your heart rate up regardless of your effort, and your power fades before the end. A strong fan and a ventilated room make all the difference.
When to skip it
Before you start
- A recently measured FTP.
- Some experience of efforts above threshold, even short ones.
Skip it if
- You have a known heart condition, or doubts about your health: get medical advice before near-maximal efforts.
- You're very tired, or a long ride or race is planned for the next day.
Origin and evidence
Level of evidence
Moderate evidenceLevel 3 of 5
Helgerud and colleagues (Med Sci Sports Exerc 2007) compared four training programmes with equal work in 40 moderately trained men, over 8 weeks at 3 sessions a week. The 4 × 4 minutes at 90–95% of maximum heart rate, with 3 minutes of active recovery at 70%, increased VO₂max by 7.2%, more than long endurance and threshold work; stroke volume rose by about 10%. The study was done in running: the transfer to cycling has not been tested. The translation into 106–118% of FTP, the VO₂max level of Coggan's zones, and 55–65% for the recovery is a Wattson approximation, as are the warm-up and the cool-down. Bottom line: a well-established protocol in running, transfer to the bike plausible but untested.
Sources
- Helgerud J. et al., Med Sci Sports Exerc 2007;39(4):665-671
Frequently asked questions
What power should I ride a Norwegian 4x4 at on the bike?
At 106–118% of FTP: 212 to 236 W for an FTP of 200 W, 265 to 295 W for 250 W, 318 to 354 W for 300 W. It's a translation of the original protocol, which is set by heart rate: check that by the end of each effort your heart rate reaches 90 to 95% of its maximum.
Does the Norwegian 4x4 work on the bike as well as for running?
Probably, but nobody has tested it as such. Helgerud's study was done in running. On the bike, the same cardiac stimulus should have a similar effect, but the power that matches it varies from rider to rider: that's why the heart-rate check is still worth having.
What should I do during the 3-minute recoveries?
Keep pedalling at 55–65% of FTP without stopping: it's an active recovery, as in the original protocol, where it's done at 70% of maximum heart rate. It brings your breathing down without letting your heart drop all the way before the next effort.
4 × 4 or 5-minute intervals?
The 4 × 4 is shorter and more intense per effort, ideal as a first go at long VO₂max efforts. Five-minute intervals build a little more time close to your maximum, a notch below the intensity of the 4 × 4. Start with the first, move to the second once it becomes routine.
How many 4x4 sessions a week?
One, sometimes two, with 48 hours before another hard session: a common guideline. The three sessions a week in Helgerud's study were part of an 8-week research protocol, in runners, without the rest of their usual training.
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