Norwegian 4x4 Intervals
Four 4 minute intervals at 90 to 95 % of maximum heart rate with three minute active breaks, the interval format developed in Trondheim.
- Duration
- 53 min
- Distance
- 10.5 kmestimated
- Effort
- 66
- Level
- Intermediate
- Focus zone
- VO2max
Your values
Targets relative to your threshold values. Enter your values to see absolute numbers.
100% is your threshold pace. Higher values are faster, lower values are slower.
| # | Step | Length | Target |
|---|---|---|---|
| 1 | Warm-upEndurance Easy jog | 15 min | 78-88% threshold pace68-78% HRmax72-82% FTP |
| 4 ×Repeat these steps | |||
| 2.1 | IntervalVO2max Hard, 90 to 95 % HRmax | 4 min | 105-112% threshold pace90-95% HRmax104-112% FTP |
| 2.2 | RecoveryEndurance Easy jog, about 70 % HRmax | 3 min | 78-88% threshold pace68-78% HRmax72-82% FTP |
| 3 | Cool-downRecovery Easy jog | 10 min | 70-78% threshold pace55-68% HRmax60-72% FTP |
About this workout
The 4x4 session consists of four intervals of four minutes at a high effort, each followed by three minutes of easy jogging. The target is heart rate, roughly 90 to 95 % of your maximum by the end of each interval. That is why this workout uses heart rate as its default target.
The format comes from research at the Norwegian University of Science and Technology in Trondheim, where it was used to raise VO2max in athletes as well as in people training for health. Heart rate takes a minute or two to climb, so the first part of each interval feels easier than the last. Keep the pace steady and let your heart rate rise into the zone.
It suits intermediate runners and anyone who trains by heart rate. Use it once or twice a week in the build phase. Runners without a heart rate sensor can run it at about 3k to 5k effort.
Tips
- Do not chase heart rate in the first minute of each interval.
- Jog the recoveries at an easy aerobic effort, around 70 % of maximum heart rate.
- A chest strap gives more reliable readings than a wrist sensor.
Origin
Developed by the exercise research group at the Norwegian University of Science and Technology (NTNU) in Trondheim.
Good for5k10kGeneral fitness
Season phaseBuild