Norwegian 4x4 for Fat Loss: Burn More in 16 Minutes
EPOC afterburn, ~16 minutes of hard work, and how the app keeps intensity honest.
HIIT Calorie Calculator
How many calories does a Norwegian 4x4 session burn? Estimate it from your heart rate or from the activity, phase by phase.
Estimates a full Norwegian 4x4 session: warm-up, 4 × 4 min intervals, 4 × 3 min recoveries and cool-down (43 minutes).
An estimate for training, not a medical diagnosis. Talk to your doctor before starting hard exercise if you have a heart condition, high blood pressure, take heart medication, or have symptoms when you exert yourself.
The two methods
Heart rate (Keytel et al., 2005). Energy use rises in a straight line with heart rate during moderate-to-hard exercise. The equations add your weight, age and sex:
Men: kcal/min = (−55.0969 + 0.6309 × HR + 0.1988 × kg + 0.2017 × age) ÷ 4.184Women: kcal/min = (−20.4022 + 0.4472 × HR − 0.1263 × kg + 0.074 × age) ÷ 4.184Without your average heart rate, the calculator assumes typical 4x4 values: 65% of max in the warm-up, 90% in the intervals, 70% in the recoveries and 60% in the cool-down (HUNT formula for max).
Activity (METs). One MET is the energy you use at rest, about 1 kcal per kg per hour. Calories = MET × weight in kg × hours, using approximate values for each phase based on the Compendium of Physical Activities.
| Activity | Intervals (MET) | Recoveries (MET) | Warm-up / cool-down (MET) |
|---|---|---|---|
| Running / treadmill run | 11 | 6 | 6 |
| Incline walking | 8 | 3.5 | 4.3 |
| Bike | 10 | 4 | 5.5 |
| Rowing machine | 10 | 4.8 | 6 |
| Elliptical / cross-trainer | 9 | 4.5 | 5 |
Calories, HIIT and fat loss
A Norwegian 4x4 session burns a solid but unspectacular number of calories. Its real value for body composition is different: it raises VO2 max, improves insulin sensitivity and helps reduce visceral fat, the harmful fat around your organs. Weight loss still comes mostly from diet. Read the Norwegian 4x4 fat-loss guide and HIIT vs steady-state cardio for fat loss, and track your waist with the waist-to-height ratio calculator.
Frequently Asked Questions
How many calories does a Norwegian 4x4 workout burn?
For most adults, roughly 350–600 kcal for the full 43-minute session (10-minute warm-up, 4 × 4-minute intervals, 4 × 3-minute recoveries, 5-minute cool-down). A 70 kg (154 lb) runner burns about 395 kcal by the activity method; heavier people and those working at higher heart rates burn more.
Is the heart-rate method more accurate?
Usually, yes, because it reflects how hard you actually worked. It uses the Keytel et al. (2005) equations, which link heart rate, weight, age and sex to energy use. Expect an error of 10–20% either way. Fitness watches use similar models.
Does HIIT keep burning calories after the workout?
A little. Excess post-exercise oxygen consumption (EPOC, the "afterburn") after a hard interval session typically adds about 6–15% of the calories burned in the session, so tens of kilocalories, not hundreds.
Is HIIT better than steady cardio for burning calories?
Per minute, yes; per session, not necessarily. A 45-minute steady jog can burn as much as a 4x4 session. The 4x4’s advantage is a bigger rise in VO2 max and insulin sensitivity for the time spent. For fat loss, total weekly activity and diet matter most.
Why does the rowing machine show a different number?
The Concept2 monitor uses a fixed formula based on watts that assumes an average-sized person, so it doesn’t account for your weight. This calculator uses your weight and heart rate.
Sources
- Keytel LR et al. Prediction of energy expenditure from heart rate monitoring during submaximal exercise. J Sports Sci 2005;23(3):289-97.
- Herrmann SD et al. 2024 Adult Compendium of Physical Activities: a third update of the energy costs of human activities. J Sport Health Sci 2024;13(1):6-12.
- LaForgia J, Withers RT, Gore CJ. Effects of exercise intensity and duration on the excess post-exercise oxygen consumption. J Sports Sci 2006;24(12):1247-64.