Triangulate your fitness and performance

Last time, we looked at how obsessing over pace can seriously affect our confidence. We touched on monitoring ‘relative perceived effort’ (RPE) and heart rate. But if you’ve never done this before, what do you do?

To get started with RPE, all you need is to score each running session out of 10 for intensity, making sure that the score fits in with the session purpose. For example, it is counter productive to run at 8 for an easy run or to run at 4 for intervals.

Another way to think of RPE might be to compare it to your starting effort for various race distances. I say starting effort because all races get harder towards the end when you fatigue. 1-2 could be a walk, 3-4 an ultra marathon, 5-6 a marathon, 7 a half marathon, 8 a 10k, 9 a 5k.

Different individuals may be inclined to underestimate or overestimate their effort but as long as the estimates are relative to each other they will be useful.

It is a more subjective metric but it gets you to think about how you feel rather than just watching numbers. This is important because it allows you to get more in tune with what your body is doing and allows you to decide when to push and when to hold back.

Heart rate monitoring is a little bit more complicated but is an invaluable tool. Firstly, you’ll need to invest in a chest strap monitor and a compatible watch (if you don’t own one already).

Many watches include wrist based heart monitoring but it isn’t very accurate compared to a chest strap. The wrist based monitoring can be very glitchy or generally non-responsive to intensity changes. However, most of the watches that have wrist based monitoring also allow you to pair a chest strap over bluetooth.

Next, you’ll need to work out what your ‘heart rate zones’ are. These are generally worked out as percentages of your maximum heart rate but it’s also difficult to find out what your maximum heart rate is.

The general rule of 220 – age is good enough to at least start off and see whether the numbers are in the right ballpark. Beware that some of the heart rate zones on tracking software like Strava and Garmin Connect also seem to be way off for most people.

To keep things simple for now, think of 3 intensity zones relating back to RPE, easy (up to 4), medium (5-7), hard (8 and up). You simply need to find your medium band. The lower end would be a pace and intensity you could maintain for a long time (several hours) and the top end is an intensity you could only keep going for an hour.

Using your maximum heart rate, try 80% for the lower end and 87% for the upper end. Over time you can tweak these numbers to be more accurate for you. Don’t forget heart rate is still a sliding scale not a stepped scale. The boundaries between intensity zones are not concrete so the bottom of the medium zone will be close to easy while the top is close to hard.

  • Example:
  • Runner Age: 36
  • Max HR: (220 – 36) = 184
  • Easy/Medium boundary (Aerobic Threshold) = (80% of 184) = 147
  • Medium/Hard boundary (Lactate Threshold) = (87% of 184) = 160

So all easy running should be 147 or below and harder interval sessions should be 160 or higher. Anything else such as marathon pace efforts or tempo running will fall between 147-160.

As said earlier, these are generic guidelines and you should fine tune these thresholds to what your body is telling you. At an easy pace, you should be able to maintain the same pace and heart rate for at least an hour. If you’re running harder than easy, your heart rate will drift up.

Just under your lactate threshold, the effort should feel ‘comfortably hard’, meaning that you feel like you are working hard but not struggling. It’s a pace you could keep going at for about an hour. Over your lactate threshold, you should start to feel heavy legs setting in and a feeling that you’d like to stop in much less than an hour.

As your fitness changes, so will your thresholds so it’s important to keep listening to your body and be honest about whether you’re pushing too hard or not hard enough. Over time, you can use the combination of all three to know exactly where your general fitness is and gauge your performance on any given day.

There is a lot of information presented here and you can get even more detailed. However, if you have only ever tracked pace then getting started on heart rate and/or RPE will open up a new dimension to your training tracking. The key takeaways are:

  1. Ensure your easy runs stay easy allowing you to hit harder workouts at the intensity required.
  2. Use heart rate and/or RPE in tandem with pace monitoring to better gauge your performance in a session.

As always, if you find this helps or have any questions about getting started, please mail me at