3 min read

Rolling Mileage Windows

Rolling Mileage Windows

A few days back, I completed the final 2 miles of a long run much slower than the initial 16. Scientists call this a bonk. It was hot, and yes, a there was a hill during mile 17, but these elements do not fully explain what happened.

Weekly Mileage

The first metric I looked at to understand my bonk was weekly mileage. At the start of training, I neurotically plan to avoid a sudden hike in distance, which I've learned is a sure fire path to injury. I am also a devoted adherent to the 80/20 rule for endurance training, which recommends that one never run more than 20% of mileage at a strenuous pace. My plan also makes sure that I never come close to the 20% ceiling. So, I know it's not my total mileage or the total hard miles I'm doing.

However, my planning consists of 4-week cycles, with three hard weeks followed by an easy week. I know I'm not breaking any weekly limits that might result in overtraining or injury. Yet, what if I change the timescale for how I assess mileage?

As a definite nonprofessional athlete I must weave my runs into daily life. As a result, sometimes my mileage and hard efforts cluster. Conversely, I watched a Kofuzi video explaining his 9-day cycles where he separates all hard efforts with two day recovery periods. Must be nice.

I decided to look at 3, 5, and 14-day distance totals in addition to the 7-day totals I use for long term planning. My 7-day total was 60 miles, typical for the past few weeks. However, on the 3, 5, and 14-day scales I hit 36, 52 and 136 miles respectively, each a peak not seen for at least the past two and a half months.

Another approach is to convert these timescale distances into 7-day equivalents. Running 36 miles over three days seems fine, but the 7-day equivalent is 84 miles.

36 miles in 3 days is equivalent to x miles in 7 days.

That is about 10 more miles than I've ever run in a week and I'm currently aiming for 50-60 miles per week. A 40% increase over my aim would have raised concerns during my planning had I been able to see it coming.

The rolling 5-day total for the week was 52 miles, a bit steep, but again it masks the real load due to clustering. 52 miles in 5 days is proportional to running 73 miles in a week. Here again, I'm floating 20% above what I intend to run.

The same overtraining story emerges when looking at my 14-day rolling total of 136 miles, averaging 75 miles per week, which is significantly high for me.

Very Normal Training Spreadsheet™️

This week has shown me that tracking weekly distance and the percentage of hard effort alone isn't enough to avoid overtraining. Looking at 3, 5, and 14-day rolling totals along with their 7-day equivalents, illuminates how real-world clustering of miles can trigger mini periods of overtraining within just a few days.