Running charts

At the start of 2021, I decide I really ought to get into better shape, so took up running. To start with I was just going to try once per month, but built up to 2 - 3 time a week. I realised if I kept it up I could reach 100 runs by the end of the year. Unfortunately after a two week holiday in summer, followed by moving house, stopped and didn't get back into it, ending the year with 61 runs.

At the start of 2022, I had found a new circuit to run and made a New Year's resolution to run 100 times (at least 3km each time). And this time I managed to hit my target. I planned to run less at the start of the year, ramp up, have a week off for summer holiday, then tail off until, just running a few times in December. As it happens, after getting a bit behind, I over-achieved in September and October, hit my target in November and then pretty much lost interest.

Doing so much running, meant I had a lot of time for think (nearly 48 hours it turns out), and one of the things I thought about was how many more runs I had to do that week and that month to keep on track with my goal. So I decided to write something that could show my runs over the year, along with the distance and pace, since I was recording that too (on my Fitbit and Garmin watch, though the latter broke towards the end of the year).

Below is the chart I generated. The code for it is here, but it I wrote it for my own use, so it's not very user-friendly.

I'm quite pleased with how the chart turned out. It makes quite a few trends clear. You can see how I gradually ramped up the frequency of runs at the start of the year and then tailed off at the end of the year. You can also see that my pace gradually increased until June, after which is got worse (not quite sure why that was - partly it was the hotter weather in July and August, but it never recovered). You can also see where I tried a few runs of longer distance, including a 10k, which was noticeably slower.

There's also a couple of things I'd not realised before: that I ran most often on Thursdays, and least often on Fridays; I ran eight consecutive Mondays in September and October. Before that, in May through to July, I only ran one Monday each month. One thing it maybe doesn't show so well, is days of consecutive runs. For a long time I avoided running two days in a row, but eventually tried in mid-July. Once I did three runs in three days, but it's not obvious from the chart.

One last thing I wanted to mention is that the radius of circles is proportional to the distance run. In general, I think you should make the area of a circle proportional to the value you want to display. Your eyes pick up the changes in area, rather than radius and if you double the radius, the area will be four times larger, so disproportional to the change in value. However, in this case I think the amount of effort required to run 10km is more than double the effort to run 5km, since the second 5km you run you are already exhausted. So I think showing the circle as four times bigger is justified, though whether the effort is four times, who knows.

Once I'd generated the chart for 2022, I went back and generated the chart for 2021. Every year since starting this I have created a new chart.

I had to adapt the code a bit to work with some flakey data from 2021. When I first started running, I only recorded the date of the run, not the time or distance. Which might be for the best, because those early runs were very short and very slow. I haved used crosses to show them on the chart.

You can see I started off slowly, both in run frequency and pace. By May I was running regularly and by June, I got pretty quick. Then in August, I had a two week break, tried to get back into for a week, and basically stopped. We moved house in September, so I wrote that month off. I tried a few times in our new house, but was clearly a lot slower, and gave up for the winter. You can also see I tried more longer runs in 2021 than in 2022.

2023 was not a good year for running. After hitting my goal of running 100 times 2022, I felt I'd done what I wanted, and also that I wouldn't be able to top it in 2023 (especially since we had a 4 week holiday to Singapore planned). I did slightly update the chart code to show total distance by month and average pace for the year.

In 2024, I got back into the swing of things. My goal was to run 500 miles (~800km) which I managed. I also tried more longer runs, and also tried improving my speed for the longer runs, getting them to a pace 5 min / km or less. This was the first year that I ran in December.

Another good year. This time my goal was 1000km, which half-way through the year, I didn't think I'd hit, but made it after a very good October and November. This year, again I went for more longer runs, and tried to get my speed up. No red runs this year.

After making these calendar style charts for several years I wanted to generate some charts that looked a trends across the years, ideally showing that I was running more often, further, and faster. So I made several new charts plotting all the data in different ways. As I write this it's nearly mid-2026 which is why that year shows partial data in these charts.

This first one was originally just going to be a bar chart of the number of runs per year. Then I thought I could make the width of the bar proportional to the average distance of a run (so the area of the bar was proportional to the total distance run that year), and colour the bar based on my average pace that year. Then I realised I could have a stacked bar chart where the width of the sections differed, so I can see all the individual runs.

This makes it clearer how consistently I go for longer runs and also makes it easier to see how I have improved my pace for the longer runs. The numbers at the bottom of each bar show the minimum, median, and maximum distance of runs that year. The vertical gridlines show 5, 10 and 15km, but I think they might just add too much noise.The colour of the year on top of each bar is based on the median pace. The colours show up better on a white background, but I like having transparent charts on my blog.

The previous chart showed number of runs, but it was hard to see which years I actually ran further and by how much. It doesn't show how I tend to run less in the winter months. This chart is simply the cumulative distance each year.

This chart shows how I tended to stop running in the winter months, until 2025 when I kept it up until the last couple of weeks (once I'd reached my goal of 1000km for the year). You can see when I went on holidays as flat weeks of no running. It also shows how I started 2026 running even more than in 2025, but slowed down so the total distance was the same, before picking up the distance again.

This chart break runs down month to show the trends over each year. The pace is shown by its position in the y-axis, the total distance for the month is shown by the size of circles. The chart shows how my pace generally speeds at the start of the year, until plateauing in summer, speeding up again in autumn, before slowing in winter. It also shows how it has been improving year on year, except for 2023.