I keep a Google Doc spreadsheet of all my training sessions, which includes mileage, any speedwork mileage, time spent in strength training and other active, intentional physical effort, and estimated distance walking. I also track known lifetime training mileage, and a self-created stat called Chops.
Chops is named after the musician term chops, which describes a performer’s current musical skill. Similarly, my Chops number provides for me an estimate of how many miles I can comfortably run at full strength over the following week.
The base formula for chops is fairly simple, calculated automatically in my Google Doc:
Chops = Total miles run in the last 7 days, to the 6/7th power
If you calculated chops for a previous day, you don’t need to calculate the previous week’s mileage. Simply add the previous day’s Chops number to today’s mileage, and take that total to the 6/7th power.
Why the 6/7th power? The 6/7 exponent degrades the previous week’s estimated mileage as the days pass, while the present day’s mileage adds to and establishes the current training volume baseline.
I wouldn’t call this a metric. It’s based on basically no verified science. Developed from observational trial and error, it largely serves to give me an idea of how much mileage I am capable of running at full rest in my current fitness, assuming of course that I train smart and don’t put myself in position to burn out or get injured.
It indicates that if I go far over the number, that will probably burn out or injure me. It indicates that if I train at less than that number, I may lose fitness. But there’s no bonafide data behind that information. It’s just a personal estimate.
And it’s worked well for me. When planning training… if I want to run, say, 50 miles a week, but my chops indicates I’m only trained for 30-35, then I need to devote some base training to slowly building up my tolerance for 35, 40, 45 miles and so on before expecting to train at my desired volume.
Meanwhile, if I want to train at 25-30 miles a week, for something like a 10K, and my chops is in the high 30’s… I can probably reduce the length of many runs, and this indicates I can comfortably incorporate new speed and tempo workouts.
Likewise, if I want to add speed and tempo workouts, but my chops has been increasing recently… this indicates I’m still working on adding mileage to my fitness base, and that adding speed or tempo workouts might be too much. Meanwhile, if my chops has been mostly steady over recent weeks, then adding new speed workouts might be safe since I’m not adding the stress of increased mileage in addition.
Basically, the stat is a tool more than anything. It tells me where my training volume is at and which way it’s trending. I can run a graph to note the trend of my chops, and this can help me determine whether making changes to my training is a good idea or necessary.
P.S.: Some other estimates you can make using chops:
- Chops divided by 7 is your recommended distance for a typical distance run. Example: If my chops is 35.0, then my typical distance run ought to be 5.0 miles (35/7).
- Chops divided by 3 is the suggested max length for your long run. Example: If my chops is 42.0, then my max long run should be 14 miles (42/3).
- Chops multiplied by 1.25 is the maximum mileage you can safely run in a peak week. Example: If my chops is 26.0, then my peak volume for a week is 32.5 miles (26 x 1.25).
- Chops divided by 6 is the maximum distance you should run in a single tempo run. Example: I want to do a long marathon pace run and my chops is 45.0. The suggested max length for my M-pace run is 7.5 miles (45/6).
- Chops divided by 12 is the maximum distance you should run in a single speedwork session (reps, intervals). Example: I want to do a hard workout of 400 meter repeats. How many of them should I do? My chops is 36.0, so (36/12) indicates I can do 3 miles of these repeats. A mile equals a bit over 1600 meters, so 3 miles equals 4800 meters. Divide 4800 meters by 400, and the max number of repeats I should do for my workout is 12. So, 12x400m.