As triathletes, we often push ourselves to the limit, seeking to shave seconds off our times and improve our performance. We all check Strava after our session, looking at our average speed, the trophies or comparing the times to the last time we did that route. But have you ever stopped to think about how harmful that is to your end-goal?

One crucial aspect of training that is often overlooked is the importance of triathlon training at a low heart rate. Yep - that means SLOWING DOWN!

This method, known as low-intensity training, can yield significant benefits for endurance athletes like you. Let's delve into this a bit more...

Understanding Low Heart Rate Training

Low heart rate training focuses on maintaining a steady, comfortable pace that keeps your heart rate within a specific range - a range that is usually much lower than your ego would like you to be training at.

This approach prioritizes aerobic efficiency, allowing your body to utilize oxygen more effectively and enhancing your endurance. Two popular methods to gauge this, and that we use with our athletes here at BLOC, are the MAF method and Zone 2 training.

The MAF Method

Developed by Dr. Phil Maffetone, the MAF method emphasizes training at a heart rate that promotes optimal aerobic function.

To calculate your MAF heart rate, you simply subtract your age from 180, then adjust based on your fitness level and health.

For example, if you're 40 years old, your MAF heart rate would be 180 - 40 = 140 beats per minute (bpm). This method helps prevent overtraining and reduces the risk of injury while building a solid aerobic base.

Zone 2 Training

Zone 2 training, a widely recognized approach in endurance sports, refers to exercising at a heart rate that is 60-70% of your maximum heart rate. This zone is often called the "fat-burning zone" because it promotes fat oxidation and increases mitochondrial density, leading to improved energy efficiency.

For a rough estimate, you can calculate your maximum heart rate by subtracting your age from 220, then multiply by 0.6 and 0.7 to find your Zone 2 range. For a more precise range, we test our athletes.

Benefits for Triathletes

Enhanced Aerobic Capacity: Low heart rate training improves your body's ability to transport and utilize oxygen, essential for endurance events like triathlons. This leads to more efficient energy use and less reliance on glycogen stores.

Increased Fat Metabolism: By training at a lower intensity, your body becomes more efficient at burning fat for fuel, preserving glycogen for higher-intensity efforts. This is particularly useful in endurance racing, as your body will be less dependant on fast-release carbohydrates.


Reduced Injury Risk: Lower intensity training puts less strain on your muscles and joints, decreasing the likelihood of overuse injuries common in high-intensity training.

Improved Recovery: Training at a low heart rate allows for quicker recovery between sessions, which is obvious once you've considered point 3 - you're not stressing your body as much, so you can recover faster, enabling more consistent and sustained training over time.

Sustainable Training: Incorporating low heart rate sessions helps maintain motivation and prevent burnout, making training more enjoyable and sustainable in the long run.

Increased Enjoyment: this for us is the most important! If you slow down, stop worrying about being fast through that strava segment and stop comparing your average speed to Fred's, then you'll find you enjoy your training so much more. There's less pressure. Not only that, but you'll find you appreciate the outdoors so much more and look forward to your sessions! All of which means your adherence goes up.

The Dangers of Ignoring Low Heart Rate Training

Neglecting low heart rate training can be detrimental to athletes. When athletes consistently train at high intensities, they risk overtraining, which can lead to chronic fatigue, decreased performance, and an increased likelihood of injuries. - This is what we often see, 99% of the time when we take on new athletes here at BLOC, they're been putting max-effort in to EVERY session, they're tired, injured, demotivated, stressed and usually reached a plateau with their times as a result.

Overreliance on anaerobic workouts without a solid aerobic base can also result in a limited capacity to sustain prolonged efforts, making it challenging to excel in endurance events like Ironman.

Additionally, high-intensity training without adequate recovery can lead to mental burnout, reducing motivation and overall enjoyment of the sport. Hence, balancing training intensity with low heart rate sessions is essential for long-term success and well-being.

Still not sure that training slow means you can race fast?

Several triathletes have experienced remarkable improvements by incorporating low heart rate training into their routines. For instance, Mark Allen, a six-time Ironman World Champion, credits the MAF method for his success. After struggling with overtraining and injuries, he adopted a low heart rate approach, leading to a significant boost in his performance and longevity in the sport.

Another example is Chrissie Wellington, a four-time Ironman World Champion. Although she didn't wear a heart rate montior, she emphasized the importance of building a strong aerobic base through low-intensity training, which allowed her to maintain high performance levels and achieve outstanding results.

Implementing Low Heart Rate Training

To incorporate low heart rate training into your routine, start by determining your MAF heart rate or Zone 2 range. Introduce introduce low-intensity sessions, aiming to spend a significant portion of your training time within these heart rate zones, usually around 80% of your total training per sport. It's essential to be patient and consistent, as improvements in aerobic efficiency take time.

MAF running in particular can be incredibly frustrating to begin with, as you'll likely need a walk-run approach to maintain your heart rate within the zone. But be patient, you'll soon be running at that super-low heart rate and your speed will increase at that same heart rate over time.

Triathlon training at a low heart rate is crucial for triathletes aiming to enhance their performance and longevity in the sport.

By focusing on aerobic efficiency, reducing injury risk, and promoting sustainable training, you can achieve remarkable results. Embrace the benefits of low heart rate training and witness the transformation in your triathlon journey.

Need help? coach@bloc-raceteam.com

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