From 10,000 steps to true peak fitness: the power of Norwegian 4×4

This method is an interval training developed by Norwegian sports scientists Jan Helgerud and Jan Hoff at the Norwegian University of Science and Technology (NTNU). This method 4×4 method is also called The Norwegian Protocol and has rightly received a lot of attention. This way of training is one of the most efficient ways to increase your cardiovascular fitness. It's really quite simple, you work in four four-minute intervals at an intensity of 85-95% of your maximum heart rate. Between each interval there is a 3-minute active rest. This means you keep moving but at a pace where you come back to about 70% of your maximum heart rate. The total programme takes about 30 minutes. This includes a proper warm-up and the time you need to let your body gradually recover from the exercise. Many people use the word cooling down, but frankly, that's a bit of an odd term. Your body does not drop in temperature in five minutes. It's not like turning on a fridge for a while. Rather, think of it as an engine that you let out quietly after a brisk ride. And while we're being critical, also warm up is not quite what happens. You can do a good "warm-up" without actually raising your body temperature. But the idea of preparing your body for the desired activity and revving up the engine beforehand still sounds somewhat like what you want to achieve

The effectiveness of the Norwegian 4×4 method has been well researched and described in the literature. The actual study that demonstrated the effectiveness of this method was published in Medicine & Science in Sports & Exercise in 2007. In this study, forty healthy, moderately trained men were randomly assigned to four different training groups, demonstrating this mode of exercise was more effective than performing the same total amount of work at lactate threshold or at 70% of maximum heart rate for improving VO2max. More recent studies from 2022 and 2023 show that training this way like Norwegian 4×4 yields better results than, say, sprint intervals for improving VO2max. And this holds true for both well-trained men and women. This confirms the power and especially the specificity of the 4×4 method for increasing your cardiovascular capacity.

Research by this Helgerud and his colleagues shows that athletes following the 4×4 protocol saw their VO₂max increase by 11% on average in just eight weeks. In addition, you can improve your maximal oxygen uptake per workout by about half a percent. This means that your heart muscle becomes stronger, allowing it to pump more blood and thus oxygen around the body per beat. After 10-12 training sessions in this way, your heart can function in the same way as an average 20-year-old. In really well-trained young people, these values are obviously higher but the results remain impressive. Also for long-term health, this is extremely effective and much more decisive than those dull 10,000 steps a day.

To understand why the Norwegian 4×4 method is so effective, we need to delve deeper into the physiology underlying this way of training. The VO2max represents the maximum amount of oxygen your body can absorb and use during exercise. It is expressed in millilitres of oxygen per kilogram of body weight per minute (ml/kg/min). This unit is considered the gold standard for cardiovascular fitness because it represents the efficiency with which your heart, lungs and muscles work together to utilise oxygen during intense exercise. So an important factor in this is stroke volume (SV). This is the amount of blood your heart can pump around per beat. The greater the stroke volume, the more oxygen becomes available. The Norwegian protocol is so effective precisely because it significantly increases your stroke volume. A higher VO2max is also associated with a reduced risk of mortality, making it one of the strongest predictors of cardiovascular health and longevity.

Your maximum heart rate (HRmax) is the highest number of heartbeats per minute your heart can reach during maximum exercise. This value forms the basis for determining your training intensity. The Norwegian 4×4 method works in the zone of 85-95% of your maximum heart rate, meaning you train in the highest aerobic zone without becoming completely anaerobic. In Norwegian 4×4, you train in the highest aerobic zone. This means that your heart and lungs are maximally stimulated, while still using just enough oxygen to avoid going completely anaerobic. In this aerobic mode, your body gets most of its energy from oxygen: efficient, sustainable and therefore longer lasting. If you go too fast, you end up in the anaerobic zone, where your muscles have to make energy without oxygen. You only keep that up for a short time because lactate, also known as lactic acid, is made as a residual product. This can be recognised as acidification during maximal exercise. 

The beauty of 4×4 is that you train in exactly the right zones. Heavy enough to train your VO2max optimally, but not so hard that you immediately blow yourself up. You could compare it to an engine that you rev heavily on the motorway, but still stays under the red revs. Powerful, efficient and longer lasting. You also train just below the lactate threshold. This is the point at which lactate (lactic acid) is produced faster than it can be eliminated. The Norwegian 4×4 protocol is specifically designed to work just below or at this point, teaching your body to better tolerate and process lactate.

One of the most special aspects of the Norwegian protocol is its enormous applicability. Research shows that short-term outcomes are determined less by age and more by your current level of fitness. In other words, the protocol is effective for both young and old and untrained and trained! 

In patients with heart disease, the Norwegian protocol has been shown to significantly increase both peak oxygen uptake and stroke volume with 16% and 17%. This means a stronger heart that performs better during exercise but also recovers faster at rest. Not for nothing is the method mentioned in the Norwegian guidelines for physical activity after heart attack and is used in clinics in Norway and abroad.

If maximum exercise is relatively new to you, start slowly. Start around 85% of your maximum heart rate and make sure you can complete all four intervals. Always use a heart rate monitor to train as accurately as possible. After a 3-4 weeks, you can slowly increase the intensity to 95% of your maximum heart rate.

Norwegian 4×4 is certainly tough, but with 1-2x a week you can already achieve these goals. Twice a week is ideal, but even one session a week can already have an effect, especially when combined with other forms of training. Whereas classic endurance training often takes several hours a week, you can achieve the same and even better results with 16 intensive minutes. That's because with 4×4 you train in exactly the right intensity zone. Heavy enough to stimulate improvement, in the right heart rate zone. The method is also extremely flexible. You can do the intervals with running, cycling, rowing, skiing or a cross-trainer. This means that your heart is the limiting factor rather than your technique or the strain on your joints. This also makes the method suitable for people with physical complaints.

Research shows that you get better results with this form of training (interval) than with traditional endurance training. With more long-term cardio, your body easily gets used to the load, causing you to plateau after a while. The Norwegian 4×4 protocol is basically a form of HIIT(high-intensity interval training), but is distinguished by the longer four-minute intervals. This duration is exactly why the results are so good. Long enough to call on your VO2max, but short enough to recover from this in between and sustain it several times in a row.

The Norwegian 4×4 method is possibly a shift in how we look at effective fitness training. Whereas 8,000 or 10,000 steps a day are a good basis for general health, the key to real results lies in targeted interval training. It increases the heart's ability to pump blood. And that is ultimately what it is all about.

With just 16 intense minutes twice a week (plus warm-up and run-out), you can achieve results that normally take much longer with traditional training. From beginners to the elderly, heart patients to world champions, the Norwegian protocol is a powerful, safe and efficient tool to transform your cardiovascular health.

So if you're serious about your fitness and health, it's time to go a step further than simply counting steps. With Norwegian 4×4, you are investing directly in a stronger heart, better performance and longer life.

Want to start? Always do a medical check-up first and consider guidance from a qualified trainer, especially if you are new to high intensity.