running km per day trend analysis

With December travel now complete following completion of my post-injury physical therapy, I've been focusing the past weeks on running versus cycling. I decided to analyze how my trend has been in running distance.

It's common to plot running distance versus week, but this can yield artifacts. For example, if the week starts on Sunday versus Monday, it could shift a Sunday long run a full week. This is too crude a time precision for good trend analysis.

So instead I plotted distance per day, including running and hiking but not walking (since walking is so ubiquitous in daily activity it's hopeless to try and track it without wearable sensors). I then fit an exponential curve using an unweighted least-squares fit to analyze the trend.

The plotted data extend back to when I started running again post-injury. I had done a few treadmill workouts well before this, in August, but these left me hobbled, and so I basically restarted from scratch on 31 Oct due to the encouragement of my physical therapist (Dave @ Potrero Physical Therapy).

So I'm basically at 6.4 km per day right now with a rapid rate of increase over the trend period (it's shown as 23.8%/week, but that should really be 26.9%/week, since the plot makes a linearization assumption of the exponential function which is invalid at this rapid rate of increase). That increase makes sense with very intermittent running, but I won't be able to sustain it, obviously. But it's good to know the trend has been upward and the distance number gives me a good baseline to judge future running as I think about going after a trail run in January.