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WARNING: This video contains profane language!

I command you to grow!

CT Fletcher says if you want big arms, you have to be OBSESSED, and work arms every time you step inside the gym.

Maybe that worked for CT to get big arms, but I wouldn’t try that for your running. The idea, "To run fast you have to go fast," is true to some extent, but that doesn't mean you should go fast every time you run. And believe it or not, going fast doesn't make you fast in and of itself.


Stress/Adaptation Cycle

For simplicity sake, we can think of the process of improvement in terms of the stress/adaptation cycle. When we put aspects of our body under stress (pressure/strain), pushing it beyond what it is used to, it will suffer a little, and in the period immediately following it won’t perform as well (think tiredness, soreness). Then, after a period of recovery, we hope that our body will emerge stronger/fitter/faster, and we will perform slightly better.


If we keep it up over time, it can look like this:

good Stress%2Frecovery adaptation cycle.png

What we want to avoid


Stressing yourself too much, so it takes too long to recover, and you likely don’t emerge stronger.

bad (too big of stress) Stress%2Frecovery adaptation cycle.png


Re-stressing yourself too early in recovery, digging yourself deeper into an overtraining/injury-risk pit.

bad overtraining pit (too soon of stress) Stress%2Frecovery adaptation cycle.png

Training so light that you recover quickly to baseline and don’t improve.

bad overtraining plateau (too little of stress) Stress%2Frecovery adaptation cycle.png

The Body's Widget Business

This stress/adaptation model is further complicated when thinking about the different types of stress you are putting your body through.

  • Metabolic Stress: Stressing the energy systems that produce energy to supply working muscles.
  • Mechanical Stress: Stressing muscles primarily, but also tendons/ligaments/bones. (and can further think about this in terms of different muscle areas)
  • Mental Stress: A hard workout is taxing on your mind as well.


Imagine the body as a widget-building business with three different departments:

  • Raw Material Digging and Transport: Getting ore out of the ground and transporting it to the factory.
  • Widget Assembly: The people and machines assembling the widgets.
  • Innovation Department: Those dreaming up the newest widget design to bring to market.

If you want to make more widgets (improvement)...

  • You need to hire more people to mine the ore, purchase more trucks to transport the stuff (or improve the transportation system). How long does it take you to hire and purchase the resources necessary to ship more ore to the factory? 
  • You need to purchase more assembly-machines and conveyor belts. They take time to get built. 
  • The innovation team needs to stop getting distracted by office politics and get to work delivering great ideas! And even when they are on the top of their game, they can only generate so much creativity.

It is possible for any one of these to be lagging behind the others, depending on how long it takes to hire workers, purchase machines, and whether you have the capital to do it. Maybe the technology side of the business (your non-running life) is using up a lot of the money trying to release their newest smartphone app (like staying up at night with your newborn child).

So going back to running... (remember: Metabolic Stress, Mechanical Stress, and Mental Stress). Each of these will take differing amounts of time to recover after a stressful workout, depending on how severe the stress is, and what other things you are doing in your life to aid or hamper recovery.

Concluding Application


Recovery is where the Magic Happens

Many mistakenly focus only on the workout. Once you crank out a hard workout, you’ve put the work in, and can live the next 24-48 hours doing whatever you want: staying up late, eating what you want, catching up on lots of busy work, right? 

But it’s actually in this period of recovery that your body is rebuilding itself, and you want to do everything you can to make sure you don’t interrupt the process by giving your body other things to worry about, otherwise it will redirect it’s resources to helping you stay up late working, instead of helping you recover faster and stronger.


Variety is the Spice of Life, and Training

Given the model of stress/adaptation cycle, it’s important to mix it up throughout your weeks (“Run your hard days HARD and your easy days EASY”), but you can also think of mixing it up in terms of the types of stress (make sure you aren’t re-stressing your quads doing a leg strength workout after a long hilly run the day before; or give yourself a mentally relaxing day after a tough breakthrough workout).


Learn More

Check out this article from The Science of Running, if you want to a little more depth (science and complexity):