If you want to protect and improve your heart health without spending hours in the gym, the Norwegian 4 × 4 workout is a powerful option. Rooted in scientific research and widely used across cardiac rehab and performance settings, it’s a protocol that delivers serious results.
What Is the Norwegian 4 × 4 Protocol?
This high‑intensity interval training (HIIT) protocol involves:
4 × 4‑minute intervals performed at 85–95 % of your maximum heart rate
3‑minute active recovery between intervals (at approx. 60–70 % HRmax)
A proper warm‑up and cool‑down bracketing the session
This structure forces the heart into zones that boost oxygen uptake and efficiency — essential components of cardiovascular health.
What the Study Shows
The study monitored 39 active men and women performing a single 4 × 4 cycle ergometer session. Key findings include:
Participants spent over 80 % of the 16‑minute interval work time between 85 and 95 % HRmax, despite a drop in power from interval 1 to 4
The heart rate steadily increased across intervals (from ~160 bpm in interval 1 to ~169 bpm in interval 4), even though power output fell from ~75 % peak to ~54 % PPO.
This means even as fatigue sets in, your heart remains under consistent high‑stress periods — the stimulus you need to drive adaptation.
The study confirms that the 4 × 4 protocol reliably targets the cardiac training zones necessary for improving VO₂ max and vascular function.
Why Just a Couple of Sessions per Week Is Ideal
According to cardiac exercise research from NTNU, doing two sessions per week tends to yield optimal results, while one session is often enough to maintain current fitness levels. Beyond that, increasing frequency to 3+ times a week can lead to diminishing returns or burnout, especially in non‑elite individuals who may struggle to recover fully.
Helgerud and Hoff at CERG report that each session can improve maximum oxygen uptake by around 0.5 %, meaning after 10–12 weeks of twice‑weekly workouts, heart efficiency can resemble that of an average 20‑year‑old.
Health Benefits for Your Heart
Improved VO₂ max and Pump Efficiency
Sustained periods in the 85–95 % HRmax zone elevate VO₂ max, which is a proven predictor of longevity and lower cardiovascular mortality.
Stronger Heart Function
The heart adapts to handle higher blood flow demands — a bit like training it to lift heavier loads over time.
Better Blood Pressure & Vascular Health
HIIT has been shown to counter atherosclerosis and improve endothelial function—even used in controlled rehab settings for coronary artery disease patients.
Time‑Efficient Calorie Burn & Recovery
With fatigue setting in across intervals, you burn lots of energy, including post‑session metabolism boost thanks to lactate accumulation and clearance cycles.
How Admac Fitness Helps You Deliver This Safely
At Admac Fitness, we can help you:
Adapt the protocol for your fitness level—especially helpful for beginners and older members
Monitor recovery, scheduling Zone 2 days or strength training to maintain balance and reduce the risk of stagnation or overtraining
If heart health matters to you — and it should — the Norwegian 4 × 4 workout is an ideal tool in your toolbox. It’s backed by science, widely used in clinical and elite settings, and when done just twice per week, can deliver serious gains without wrecking your energy.
Want to improve your health and fitness? Let the AdMac Fitness Personal Trainers help…
AdMac Fitness has been helping the people of East London transform their health and fitness for nearly a decade.
We help people using tried and tested fitness approaches. Our expert team of personal trainers, based in both Bow and South Woodford can help you get a grip of your health forever. With our guidance and experience, you can relax knowing that your fitness journey is going to be guided by some of the best personal trainers in East London.
For more information on who we are, what we do and how we can help you achieve your health and fitness goals, contact us on… 07921465108 or email us at admacfitness@gmail.com. We look forward to hearing from you!
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