QT: Diz’s Law of Accumulated Fatigue for Runners

I’m not sure why, but I was recently reminiscing back to my high school chemistry days.

Anyway, the subject that was rattling around my brand for some still-unknown reason was Boyle’s Law.

Chemistry Refresher Course

You’re familiar with Boyle’s Law, yes?

Well then, here’s a quick rundown.

Boyle’s Law defines the relationship between volume and pressure of a fixed amount of a gas at a constant temperature.

If the amount of volume the gas can fill increases, the pressure decreases.

And if the volume is reduced, the pressure increases.

Pretty straight forward, right?

What Does Boyle’s Law Have to Do With Running?

Well, at least not anything directly.

You see, Boyle’s Law is all about relationships within a closed environment.

And how if you alter one variable within the environment, there is a predictable response from the other variables.

Those relationships? Have everything to do with running.

More specifically, those relationships have everything to do with how our bodies respond to the demands of running.

And that relationship is the genesis of Diz’s Law of Accumulated Fatigue.

Diz’s Law of Accumulated Fatigue

Before we dive into the intricacies of Diz’s Law of Recovery, let’s look at the law as a whole.

My law (seriously, how douchey am I to “create” my own law?!?!) asserts that the amount of fatigue that will build up in your legs is relational to training volume, training intensity, and how much recovery work you’re doing.

If you increase your volume and/or intensity, your level of fatigue also increases.

But if you increase the amount of recovery work you do, your level of fatigue will decrease.

Seems simple enough, eh?

It is definitely pretty straight forward.

But that doesn’t necessarily mean that it’s simple.

A Closer Look at Each Component

In order to really understand Diz’s Law of Accumulated Fatigue, it’s important to make sure that you’re clear on how each component of the equation works.

Training Volume

To put it simply, training volume refers to how many miles you’re running in a given amount of time.

Miles per day. Per week. Per month.

The more miles you’re running, the more fatigued your legs will likely be.

Training Intensity

Training intensity refers to how hard you are working when you’re running.

Note, this isn’t the same thing as speed/pace.

Yes, if you’re running faster you’re typically running at a higher level of intensity. But there are plenty of situations where your pace is slower than usual but you’re working at a higher intensity.

Recovery Work

This is probably the least straight forward component of the law, because recovery work comes in so many different forms.

We all have a natural rate at which we recover from physical activity, but we have the ability to speed up that rate in a variety of ways.

Getting more sleep. Easy activity. Getting a massage. Quality food choices. Doing yoga.

Those are just a few of the ways we can reduce our levels of fatigue.

The Relationship Between the Parts

This is where the rubber meets the proverbial road.

I think it’s pretty straight forward to see how a change one front impacts the amount of accumulated fagitue.

But where it gets a little more complicated is how a change in one variable impacts a change in another variable, which likely has a bigger impact on the amount of fatigue that will accumulate over time.

This year, one of my goals is to run the year.

One of the ways I’m looking to get all the miles is to add some running on Wednesdays to my usual mix.

In doing so, I’m increasing my training volume which results in a bit more accumulated fatigue.

If only it were that simple…

You see, in addition to increasing my volume I’m also decreasing my recovery work!

How so?

Well, I used to do some easy cross-training on Wednesday instead of running.

So not only am I adding running to the mix this year, but I’m also not doing my Wednesday rides.

That combination of factors has resulted in additional fatigue building up in my legs, and it is something I must address if I’m hoping to hit my goal of 2,020 miles by the end of the year.

The Blessing/Curse of Accumulated Fatigue

Is accumulated fatigue a major issue? Something that should be avoided at all costs?

The fact of the matter is that pushing our bodies to the point where fatigue accumulates is necessary for our growth as runners.

That said, this is one of those cases where too much of a good thing is not a good thing.

If too much fatigue builds up in your legs, it can limit the quality of your runs.

It can also make you more succeptable to injury.

That’s why it’s important to monitor, and manage, the amount of fatigue that builds up in your legs.

If too much is building up and it’s impacting your training? Figure out where you can either cut back on your volume and/or intensity or add a bit more recovery work to your routine.

And if you’re never feeling tired/fatigued due to your workouts? There’s a case to be made that the work you’re doing isn’t providing many benefits in terms of improved fitness.

In this case, maybe an increase in volume or the introduction of a harder workout on occasion may be a good idea.

(I can’t think of a situation where reducing the amount of recovery work you do would be a good idea, however.)

As you’re continuing on your running journey, keep Diz’s Law of Accumulated Fatigue in mind.

Because fatigue in something that you definitely want to keep an eye on, and manage appropriately, along the way.

Follow Diz's Law of Accumulated Fatigue to avoid doing more than your legs can handle. #runchat Click To Tweet

What is Your Take on My Law?

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