Nuances of Heart Rate Training for Runners (Part 1)

Hi there! 👋

Hope your training is going well! In this month’s newsletter, we wanted to talk about heart rate zones, and in particular, certain scenarios where you might need to ignore your heart rate and pay closer attention to other factors such as how the effort feels. This is a two-part email, since there’s a fair amount to explain here! 

Firstly, let’s start with discussing how heart rate responds to changes of intensity. We all know that heart rate takes time to respond when you begin running harder. In fact, it can take several minutes for your heart rate to stabilise at a level that reflects the intensity you’re working at.

Does this mean that, through those first few minutes where heart rate is still rising, you’re not working as hard? 

Absolutely not!

Even though your heart rate may not have fully risen, you’re still asking your muscles to contract at the same force, meaning you’re recruiting the same number of muscle fibres, and the energy demands within the muscles are still largely the same. 

In fact, certain systems are being worked harder through these first few minutes, such as your ability to extract oxygen from the blood passing through your muscle capillaries, and your ability to shuttle lactate between muscle fibres. 

You might argue that since your heart rate is not as high, the heart muscle itself is not being trained as effectively, and this would be a fair point. However, once you get beyond a beginner level, the extent to which you can develop the heart muscle is relatively minimal, and by far the biggest training adaptations occur at the muscles. From the perspective of the muscles, you’re working just as hard (if not harder) at the beginning of an interval or hard effort compared to the end, even though this isn’t reflected in your heart rate. 

Ultimately heart rate is just one snapshot of how hard the body is working, and doesn’t tell the full picture. 

So let’s look at our first scenario where you might want to ignore heart rate…

1. First Few Minutes of an Interval/Effort

We have heard runners say that, if they have an interval session planned such as 3x 10-mins at a Zone 4 heart rate, they feel the need to add an extra effort on to the end of the session, to account for the fact that heart rate isn’t in the ‘right zone’ for the first few minutes of each effort. 

However, as should now be clear, these first few minutes still represent productive training time, and you’re still working the intended energy systems and muscle fibres. The extra effort is unnecessary. 

Furthermore, by adding on an additional effort beyond what was planned, you run the risk of either overtraining, or compensating by reducing the intensity slightly to account for the higher volume of running, which means you’re not working the body in the way you originally intended, and may not get the adaptations you’re looking for. 

Through the first few minutes of an interval, we’d recommend paying attention to how the effort feels subjectively, your speed or pace (if running on a consistent gradient) and/or your power if you have a power meter. These are far better indicators of running intensity in this scenario. 

In next month’s email, we’ll continue to explain a couple more scenarios where you should largely ignore heart rate in your training…

News

We’ve been adding to our selection of training plans this month. We now have a selection of different 50km trail/fell race plans, as well as several fell/trail marathon plans. You can view the options here, and we’ll be adding more over the coming months! All plans come with a detailed PDF user guide to help provide guidance you’d usually get from a coach, and the plans are tailored to three different runner levels:

• Improver:already completing 4-5 hours of running per week and comfortable with running at least 1-hour at a time.

• Intermediate: already completing 5-7 hours of running per week and comfortable with running at least 2-hours at a time.

• Advanced: already completing 7-9 hours of running per week and comfortable with running at least 3-hours at a time.

That’s it for this month! If you’re relatively new to the mailing list and want to see previous instalments, then you can do so here.