The One Key Number Behind Our Marathon Training Plans

We won't do you like one of those cooking blogs where you're trying to get a chicken piccata recipe, but the chef makes you read their full life story first. The number is 80... 80% to be exact. There ya go. Bon appétit!

You can probably guess where we're going with this 80% figure, and ya could stop reading now, but that would only be about 10%. And that's just not gonna cut it. So humor us for a moment and allow us to explain our light science, math, and philosophy behind this wonderful percentage...

Of our 16-week marathon training plans, we encourage Bandit Program athletes to complete 80% of it. We have two mileage-based plans: 30-55 MPW, and 45-70 MPW. Let's take a quick look at what 80% looks like...

The lower mileage plan is 21 marathons worth of running, and the higher mileage plan is good for 28 marathons. Take that in for a sec.

There's 112 days in a 16-week marathon training block. It is highly unlikely (read: impossible?) that all 112 of them will go according to plan. At some point, you're probably going to come down with an illness or a nag, work will run late, a wedding will land on the same weekend as a long run, or we'll get one of our patented wildfires causing terrible air quality. 

80% is not some magic physiological threshold. The body does not unlock marathon fitness the moment your training log reaches 80.0%. It is a practical philosophy: enough structure to demand real commitment, with enough flexibility to account for the fact that training happens inside a life...

No single 45-minute run makes you marathon-ready. No single interval session transforms your anaerobic system. No single long run finishes the job. Fitness is created by repeatedly applying stress, recovering from it and doing it again. The body responds to the accumulation of those cycles across weeks and months. It is the full body of your work that matters—not whether every single workout was checked along the way. And put other way around, your fitness does not disappear because your calendar became inconvenient on the Tuesday of Week 7.

CAVEAT: NOT ALL MILES ARE EQUAL

Completing 80% of the mileage is not necessarily the same as receiving 80% of the plan's value.

Imagine one runner who completes nearly every long run, most of the Wednesday speed sessions and the majority of the supporting easy mileage, but occasionally drops a recovery run when life or fatigue intervenes. Or perhaps, they cut a long run slightly short or subtracts a rep or two off in an interval session.

Now imagine another runner who records the same total mileage but repeatedly skips the long runs and harder sessions, replacing them with comfortable miles whenever convenient.

The totals might look identical, but the value is not. 

Here's our rules of thumb when aiming for 80%..

1. Protect the long run.
2. Protect the primary speed session.
3. If you're not feeling up to the full session, cut it short rather than fully out.
4. Think about recovery miles in time rather than miles and go slow. Your job is not  to sustain or gain fitness in recovery runs, it's to help your body build back up. Now read that back.

So, the goal is not to complete a random 80%... It's to preserve the architecture of the plan while factoring in the realities of a full life. Think about evaluating your completion percentage two ways:

• Volume Completion = Miles Completed / Miles Prescribed
• Structural Completion = Priority Sessions Completed / Priority Sessions Prescribed

And the last few things we'll say on the 80% rule:

• Athletes will often think because they missed a session, they need to make up for it and go harder/longer the next time. Wrong. Don't chase it. Let it go. Stick to the plan. If you chase, you will negatively impact the next sessions.
  
  
• Perfectionists rarely make good marathoners. If you chase 100%, you'll almost inevitably get hurt because you'll be ignoring what your body is trying to tell you it needs. And psychologically, a person who aims for 80% and hits 80% is better off mentally than someone who aims for 100% and (regretfully) hits 80%. 
  
  
• There's a difference between listening to your body and negotiating with yourself every morning. Skipping a run because of a little rain is not the same as because your body is tired. Be honest with yourself.

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If you're training for a marathon this Fall or Winter, try out our 100% free training app, The Program.