How do I usefully interpret running metrics?

I haven't been running for long. I've got a heart monitor and a GPS watch (all the gear and no idea), but I get a buzz from seeing the metrics anyway.

I'd like to know how to interpret the metrics I collect though.

What is the key elements to look for in these metrics?

  • 2
    Voted to close as it is entirely specific to the individual. I would put it to you, though, that the only metric that counts is race times.
    – JohnP
    Commented Mar 6, 2013 at 0:04
  • @JohnP The only metrics I have are mine, any other examples are fine (I was hoping people might offer their's up as examples too). What I want to know is how to interpret the metrics so I can spot problem areas and train to improve.
    – BanksySan
    Commented Mar 6, 2013 at 0:09
  • 1
    @Kate Nothing stands out as abnormal, the metric I wanted to improve I assume is the heart rate. I'm doing the Tough Mudder in September and so want to be as healthy as possible for it. Mostly though, I wanted to know what to look for in order to spot things I might not know.
    – BanksySan
    Commented Mar 6, 2013 at 11:13
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    @Dave Newton, its pretty clear to me that Banksy is asking for a way to extract some useful knowledge abut himself, his training and the fields in which he lacks from the data he can collect using his equipment. He is NOT asking you to interpret them for him (which is good, as that would be a too localized question). This question has the potential to help others with similar problems. Maybe the answer is - you cant really get any reasonable and useful conclusions from these metrics/data, but still, I think this is a good question
    – K.L.
    Commented Mar 7, 2013 at 9:55
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    I think I know a way to answer to keep this as a question. If the question would be reworded to say something more like "I have a GPS, these are the metrics it produces. How can these metrics be applied to a training program?" or similar it might be better.
    – JohnP
    Commented Mar 7, 2013 at 18:16

2 Answers 2


As per JohnP's answer, looking at individual GPS logs in isolation is of limited use: if you're trying to track improvements then so many other factors (fatigue, weather, stress, etc) can make it look as though you performed 'better' in one session than another. Garmin's interface isn't very helpful at examining this because (mostly) it presents each run in isolation from the rest.

A more attractive way of looking at the data is to put it into Smashrun - gives you some handy things like average speed over a month and the trailing 90 days mileage, but again, it may not be so helpful if you're doing periodisation, and (at the moment) it struggles to interpret interval training, but there's some trending. Strava is also useful for comparing your performance on particular segments, but I find the emphasis on competing with other people to be needlessly distracting.

Where I think it can be useful is when you're doing interval training. Your heart rate from the half marathon is pretty flat throughout, whereas on the other two runs it moves around a lot, and (from what I can see of the elevation and your pace) I don't understand why it's moving about so much. Compare with this track session I ran this week: http://connect.garmin.com/activity/426003767 - what I'm looking for is how fast my heart rate drops between each 1200m lap, and how consistent I am through the laps themselves. Very roughly speaking, the faster your heart rate goes down from the end of a period of hard exertion, the fitter you're getting, and the more consistently you can get your speed and heart rate to match up, the better you're getting at running at that particular speed.

Since I've got a foot pod, I can also track cadence - in this case, I can see that I was probably starting each interval a bit too quickly, as my cadence declines on every one. Again, I'd be looking for ways to improve your consistency at running at a certain speed, and knowing that I tend to go out a bit too fast then becomes helpful the next time I run that session.

When you're not running laps of consistent terrain, each log is less helpful in isolation; these tools are most helpful if you're comparing the same thing on different days, and you have lots of different data points to compare.


The problem with GPS and heart rate and all the data that the little gizmo's give you is that they are short term metrics, that are generally only applicable to that day and point in time. Yet everyone wants to use them to change the way they train tomorrow, and it doesn't work like that.

Take your heart rate. Today you go out and you run a 6 mile out and back course, and it's windy and cold, and you end up with an average heart rate of 180. Four days after that, you run the exact same course, and it's windless with moderate temperatures, and your average heart rate is 165. Did you suddenly gain fitness in those four days?

Data is data. It is best collected and averaged out over long periods of time (months to years), and instead of comparing one week to the next, you look for trends in whatever metrics you are tracking. So if you are looking at heart rate, you want to see a general trend lower over the same types of courses/conditions as you get fitter. Or, if your heart rate is staying the same, hopefully you are running it in a faster time.

Conversely, if you track it and over the last 3-4 weeks you are noticing a rise in the heart rate, then you can look at factors that influence it. Have you been stressed, eating different, not sleeping, overtraining, etc. and correct it.

The reason that I stated the only metric that matters is race times, is that you can train according to the numbers all you want, but if your race times are not improving, then either you have maxed out your abilities, or there is something else that you need to consider.

FWIW, I track mileage and training times, and I track power with a powermeter on the bike, but I've never tracked heart rate at all. If they ever come out with a commercially viable powermeter for shoes (There are some attempts out there, but I'm not impressed yet) I'll be the first one in line, but HR (to me) just isn't a great metric, there's too much that influences it. However, other people swear by HR based training, so your mileage may vary on that one.

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