The Best Training for Your Heart

How Do You Train the Heart?

The most effective way to train your heart is by exercising at an intensity where it becomes completely filled with blood — and stays there long enough to get stronger. Considering that your total blood volume is about 4–5 kilograms, it takes about 1–2 minutes at the right intensity to fully load the heart. From there, you need to maintain that intensity for another 2 minutes to get maximum benefit.

That’s exactly what the 4x4 interval method is designed to do. Based on exercise physiology research, 4x4 training specifically targets the heart and circulatory system.

What Is a 4x4 Interval Session?

A 4x4 workout consists of:

• Four 4-minute intervals
  
  
• Three-minute active breaks between each interval
  
  

During the first two minutes of each interval, your heart fills with blood. The following two minutes keep it working at full capacity. The 3-minute breaks give your body time to flush out lactic acid, so you’re ready to complete the next interval at the right intensity.

It’s long enough to challenge your cardiovascular system — but short enough to avoid excessive fatigue.

4x4 in a Nutshell

Here’s what a full session looks like:

• 6-minute warm-up at moderate intensity
  
  
• Four 4-minute intervals, ideally on a treadmill with at least 5% incline
  
  
• During the intervals, reach 85–95% of your max heart rate by minute 2
  
  
• You’re at the right intensity if you’re breathing heavily after 2 minutes, but feel no discomfort or stiffness
  
  
• 3-minute active breaks between intervals, where your heart rate drops to around 70% of max (a pace where you can still talk)
  
  
• 5-minute cooldown at a comfortable pace
  
  

How to Find the Right Intensity

Not sure what your maximum heart rate is? No problem — you don’t need fancy gear to train effectively. Here are some simple rules of thumb:

• After each 4-minute interval, you should feel like you could go for 1 more minute
  
  
• After completing all four intervals, you should feel like you could do one more
  
  
• If you can hold a conversation during an interval, the intensity is too low
  
  

Want a rough estimate of your maximum heart rate? Measure your heart rate at the end of the final interval and add 15 beats — that will give you a good approximation.

How Often Should You Do 4x4 Training?

Each weekly session of 4x4 training — beyond the first — improves endurance by about 0.5%. Just two sessions per week are enough to maintain a biological age of 20, even as you grow older.

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