Run efficiency analysis

Running – for many it’s the greatest sport in the world. For others, it is the hardest part of a triathlon. Hour after hour is invested into steady state training. Training theory claims that it is worth the effort, but what are the actual training effects on your body?

For most runners, who don’t spend a lot of time analyzing their data, this question is still unanswered. Do you actually manage to adapt and optimize your physiology to run more efficiently, i.e. faster with the same heart rate? Or do you need to change your training?

Läufer auf der Straße


Steady state training improves your body’s efficiency in every sport. During and after extensive training in low intensities, your body adapts its metabolic processes in order to use less energy for the same effort. These adaptations include:

  • Movements get automated and more efficient
  • Improved fat metabolism
  • Adaptation of the cardiac system
  • Improved oxygen intake
  • Improvements of the nervous system triggering your muscle cells

These adaptation processes start after a training duration of at least 75 minutes over the course of several months.

My run efficiency

Analyzing your run efficiency isn’t easy at all. The heart rate is affected by so many factors that comparing two runs on the same course at different days to determine run efficiency progress is virtually useless. Differences in your heart rate at a specific pace might be caused by different temperatures, stress levels, your sleep the night before, headwind, etc. You would have to analyze a lot of runs to detect any underlying trend in your run efficiency.

Another way of testing your efficiency is doing regular lactate tests. However, these are not always available and they are rather expensive.

The run efficiency analysis by PerfectPace continuously scans all your run data and tells you how much your run efficiency has improved. Trainers especially love this tool, as it shows them how effective their athlete’s training really was.

Credits @derSteira - Markus Fritz

How it works

PerfectPace analyses your runs and presents you with a simple chart that shows your run efficiency progress. For every month, you see what heart rate your body required to run at a specific pace. When your training is effective in improving your run efficiency, you’ll notice a downward trend; for the same pace you require a lower heart rate.

Flat segments

The data you see in your run efficiency analysis is of course derived from your run workouts. However, not just any data can be used. For instance, during a short sprint at the start of your workout, you will achieve a high pace at a low heart rate. But this is obviously not an indicator of high run efficiency!

The analysis only uses the parts of your run workouts where you ran with a stable heart rate on a flat course. In this context, stable heart rate means that it does not change faster than three beats per minute. From this filtered data, your average heart rate for each of your pace zones is calculated. With a bit of statistical analysis, this results in a model of the relationship between your pace and heart rate. It represents the reaction of your body to various loads during a specific month of your training. The change of this reaction is shown in the run efficiency analysis.

Not everyone has a flat course available for training. Therefore, there is also the option to analyze your run efficiency based on all your run data.