When you think about it, a lot of running involves math. The standard measure of performance (pace) is supported by explanatory metrics such as cadence, stride length and heart rate. That data allows us to analyze trends and calculate indicators like V0² max. I’ll admit to loving statistics, but I know many people don’t.

Besides my increasing skepticism of my heart rate monitor and my frustration with a stagnant pace, I’m not going to write much about any of that stuff today. Right now I’m looking at statistical frequency. Now don’t stop reading, this isn’t really about math. It’s more about finding an optimum balance between running and resting.

When I stopped my daily commute at the beginning of May, I committed to increasing the number of miles I’d run a month. Seven years ago, I was averaging close to 20 miles a week. I typically took one rest day and totaled more than 80 miles a month. I did shorter runs during the work week and longer distances on weekends. When I was training for a 10K or a half marathon, I would cover as much as 12 miles.

Last April I ran a pathetically low 27 miles. Since then, I’ve steadily climbed from 57 in May to 82 in September. Just like I was doing doing in 2012, I’m again running six days a week and reaching 80 miles a month. However, that’s where the similarity ends. My pace has declined measurably and I’ve only run more than four miles twice this year.

I’ve decided to make a change in my run schedule to give me more recovery time and allow for longer runs. My average distance per run is about 3.1 miles and getting back to the 5+ range will hopefully boost my stamina. If that happens, I may be able to nudge my pace back into respectable territory.

So here’s the math problem:

1. There are seven calendar days in a week. I am currently running six days each week and taking a rest day every Wednesday.
2. The ratio of run days to rest days is 6:1.
3. Running six days in a row is fatiguing and it invites repetitive injuries, especially to the feet.
4. The cumulative fatigue discourages longer runs.

Here (I think) is the solution. See chart at top:

1. Instead of keeping a specific rest day every calendar week, I will run six days out of every seven, but will insert a rest day after every third run.
2. The ratio of running to resting drops from 6:1 to 3:1.
3. Rest days happen based on the sequence, not on a fixed day, so some calendar weeks can have two recovery days.

This change has many positives but it could have an effect on my monthly mileage. The fixed rest day method typically resulted in 26 run days a month while the 3-on, 1-off method will be closer to 24. It will be harder to reach 80 miles a month at my present distance-per-run average, but I’m hoping that more frequent rest days will encourage me to add more miles per run. Knowing I’m never more than three days to a recovery day (or cross-training on the rower) should be a motivator.