By James Eacott
Now that you’ve started using a heart rate monitor in some sessions each week, we look at how you will use it both during and, importantly, after your session. Then, how you are going to use heart rate to improve race performance.
It’s all covered here!
Before we get stuck in, I’ve had a couple of questions after the previous articles about the differences between Current HR, Lap HR and Average HR. So, I’ll clarify that now…
What’s the difference between Current, Lap and Average HR?
Your GPS watch will likely give you three heart rate display options:
- Current HR. Your heart rate at this moment.
- Lap HR. This is your average HR for the Lap you’re currently in. Get into the habit of hitting Lap every time you start and finish an interval.
- Average HR. This is your average for the entire run.
How to use HR during and after a session
For all sessions, heart rate is useful to observe both during and after a session. Glancing at your watch mid-run will inform you whether your pace and effort are on point to nail the objectives of the session.
Looking at the data after the session (Garmin, Suunto, Polar etc all have platforms which allow you to upload your data and review) is also good practice to get an overall picture of the session.
Zones 1 and 2
As I mentioned before, using a HR monitor for your Zone 1 and Zone 2 sessions is key to ensuring you keep the effort level low enough. During the session, display both Current HR and Average HR. Keep an eye on the numbers and make sure it doesn’t drift above that Z2 ceiling.
You can delve into the file post-run to see if you had any peaks or troughs, which may occur when gradient and terrain change.
When it comes to Zone 3 tempo sessions, heart rate plays a critical role in keeping you within the right zone. During the session, you’ll want to be able to see both Current HR and Lap HR. You’ll want to focus on both numbers. Here’s why:
If I’ve done an easy warm up for 10 minutes, my heart rate might be 125bpm. I hit Lap and start running at tempo pace. My HR doesn’t change immediately, but after 90 seconds it’s up to 145bpm. Which is still on the low side for a tempo session, for me. However, after 2 minutes, it’s at 152pm and I’m in the right zone – I continue to run at this HR for the remainder of the interval.
At the end of the interval, the Lap pace (the average for that Lap) has me at 146bpm. No problem though, it’s only lower because I started the interval at 125bpm and it took a few minutes for my HR to respond (and thus, Lap HR to adjust).
As a result of this lag, my advice would be as follows: When doing shorter intervals, of less than 5-10 minutes, it’s best to look at Current HR rather than Lap HR. Longer than 10 minutes, and Lap HR becomes a better reflection of your work.
Zones 4 and 5
Running around and above threshold is still a heart rate affair and follows the sample principle as Zone 3. That is until you become really proficient and so in-tune with your body that you “just know” what your effort is, using a HR will help ensure you’re hitting the right effort level to maximise gains.
Look for improvements. If your training is successful, you should see your HR decrease for the same speed. If 08:00mm used to have you at 140bpm, you’d hope to see this drop to 135bpm after a few weeks or months of structured training.
Keep an eye out for anomalies. If you discover HR spikes in your data post-session, this is a good indicator of your weaknesses (or just poor pacing!). You might struggle on the ups, or perhaps HR drops too low when descending and you need to push harder on the downs. You can use these anomalies to find your weaknesses and inform your training so that you focus on them.
Racing with heart rate
Heart rate is a very useful tool when it comes to racing ultras. It’s a much better indicator of how your body is responding to what you’re asking it to do than pace is. If you race flat road half marathons and marathons, pace becomes a better tool to gauge effort.
This is because there aren’t usually the range of external factors at play which can affect your physiology during an ultra, such as:
- Changes in terrain
- Sleep deprivation
All of the above can have a physiological effect over time which deem mindlessly sticking to a set pace futile. Your HR, on the other hand, will tell you how hard you’re pushing, despite all the above. It’ll also tell you what your body is doing despite how you are feeling.
So while you may be in a trough, your HR is low and under control, which might tell you, for example, that you don’t need to slow down, you just need some food.
It’s important to keep a few things in mind.
When you choose to work harder, for example up a hill or to overtake a competitor, keep an eye on what your HR is doing. Have a ceiling over which you will not let your HR rise for more than a few minutes – this will be somewhere around your threshold heart rate.
Spending too long over this threshold may feel easy for a few minutes, but you’ll be burning matches that, in an ultra, need to be saved for efficient pacing and consistent effort output.
Remember, the quickest route from A-B is to pace as evenly as possible. Ultimately, courses are lumpy and this means your effort will change somewhat. But utilising HR will allow you to keep these changes under control and keep your HR as constant as possible.
Remember, HR is very individual and to get the best from yourself, you need to use your own zones. Complete the Test I described in Part 1, and don’t worry if your threshold HR is higher or lower than your mates.
The final piece of advice, and perhaps the most under-utilised benefit of measuring HR is this: heart rate is a very useful tool to keep track of overtraining. On a regular basis, take your HR the moment you wake up.
This HR should remain quite consistent each day, perhaps varying by +/- 5bpm. But on days where you’re particularly fatigued, your HR will be a higher. This is a hugely valuable indicator informing you to either take a day off or just take it easy.