What is the real opportunity cost of 100 mile weeks?

I am an adult who runs 30-40 miles per week and I do about 10-15 races per year. I consider myself an actual runner (though some on this MB would call me a hobby jogger). I am in my mid-30s and I can still throw down a sub-5:00 mile and I can still win some local/regional 5Ks.

I was thinking the other day: As an adult with a family and career, how do people run 100 mile weeks? (I am talking about non-professional runners, which is 99+% of this MB). This led me to the question: What is the real opportunity cost of running 100 mile weeks (as opposed to 40 mile weeks)? Here are some initial thoughts:

1. The Value of Your Time

Let’s say that someone has an earning potential of $25 per hour.

If you run 100 miles per week and you average 7:00 pace, that is 700 minutes of running per week.

If you run 40 miles per week and you average 7:00 pace, that is 280 minutes of running per week.

So that is a difference of 7 hours per week.

At $25 per hour, your running is costing you $175 per week in earning potential (or about $9,000 per year).

2. Grocery Bills

Let’s assume that groceries for someone running 40 miles per week if $100.

Let’s also assume that someone running 40 miles per week is consuming around 20,000 calories per week and someone running 100 miles per week is consuming 30,000 calories.

The increase in groceries would be about 50% … so groceries will cost $150 per week.

That is a difference of $50 per week (or about $2,500 per year).

3. Running Shoes

Let’s assume that a runner pays on average $100 for each pair of running shoes.

Let’s also assume that this runner replaces shoes every 300 miles.

At 40 miles per week, they will go through about 7 pair of shoes per year.

At 100 miles per week, they will go through about 17 pair of shoes per year.

That is a difference of 10 pairs of shoes (or about $1,000 per year).

Just looking at these three factors … running 100 miles per week costs you over $12,000 more in opportunity cost per year than running 40 miles per week.

To be clear, I have no problem with people who run triple figure mileage … I just want to make sure they understand the opportunity cost involved in said activity.

Thoughts?