The Stress of Life:

Adaptation is a fairly simple process.  You apply a stimulus, or a “stressor” to the body and it adapts.  Go lift weights, break down some muscle, and your body responds by making the muscle stronger.  The actual process along that path is very complex and we’ll go into that shortly, but really training and adaptation is as simple as that.

Stimulus-> adaptation.

As coaches, we obsess over the workout part.  We carefully plan what needs to be done and when it needs to be done in order to get the adaptations we want.  We know when to apply that threshold run to get a generalized aerobic stimulus or when to start those 400 repeats to cover the other side of the spectrum.

In fact, the entire coaching profession is based on the assumption if we give a workout and give enough recovery, then they’ll adapt.

That’s generally a safe assumption to make, and often times it comes true.  If something goes wrong, we generally think, oh we pressed it too hard and they couldn’t adapt, or we didn’t give them enough recovery, and so on.  After a while, as coaches, we get a handle on how much someone needs to be pushed and how much they need to recover to continue along the path of gradual adaptation.

But…are we missing part of the picture?

We control everything that is running related, but that creates a situation where we tend to think in isolation.  If we give X hard workout on Monday then follow it up with maybe a shorter easy run on Tuesday and Wednesday, then we’ve covered the hard part and the recovery part.  Everything should be good.  But what about life outside of running?

General Adaptation Syndrome:

The concept of stress wasn’t always as prevalent as it is today.  A Scientist named Hans Selye essentially formulated how we respond to stressors and thus paved the way for us exercise nerds knowing how to program training based on adaptation.

He stumbled upon doing a lot of experiments on some mice and applied various stressors to them (think heat, cold, poking and prodding, etc.) and found that no matter what the stress, there was a generalized response to them.  So the body had a sequence of events that it went through no matter the stressor.  This and a bunch of other studies gave rise to the concept that we respond to stress in a certain patterned way.  So, regardless of what the stressor is, there’s a generalized response that accompanies the specific response.

Most people think of this in terms of physical stressors only.  But the reality is that your body is programmed to respond in similar ways to mental stressors too.  So, you get mentally stressed out, your cortisol levels jump, you’re on edge and your sympathetic nervous system is firing more, just to be prepared.

Adaptation to workouts:

As coaches, you know there’s only so much each athlete can handle in terms of volume and intensity.  These are your stressors in training.  If we go over some amount for each person, they’ll “burn out” and performance will suffer because they simply haven’t adapted and absorbed the training.  The key concept to remember is adaptation.  We have to be able to adapt to the stressors.

What Selye found is that if he removed the stressor soon enough, the mice would adapt and become better able to resist that stressor.  If he left that stressor there too long, in many cases the mice would die or become less resistant to that stressor.  So the key was giving them enough of a stressor to adapt but not too much.

Tieing it all back together now, if we have our running related stressor (workouts), and we apply that at the same time as when some other stressor is going on in our athletes life, will he have enough room for adaptation?

The answer is sometimes no.

You only have so much “stress” you can adapt to.  And as we learned earlier, there is a general response to stress so that there is overlap between doing 4x1mile repeats and being stressed because your boyfriend just dumped you or you are about to take a mid term.  Prepping for that mid term gives you many of the same stress responses that you had in prepping for that workout.  So if we got both going on at around the same time, we’ve got your body trying to adapt and handle two different stressors.

If it’s too much for you, your body won’t adapt to the workout.  Even if the workout in itself wasn’t too hard, when it’s combined with something else that is a stressor it might push you over the top.

In essence, your body only has so much it can adapt to.  It’s best thought of as an adaptation reservoir.  You have so much “energy” you can use to adapt and handle different stressors.  If you use up the reservoir, it’s depleted and you won’t adapt until it’s filled up again.  So if we go and do that hard interval session in the middle of finals and our athlete maybe just broke up with his girlfriend and is generally freaking out, will he adapt?

Where’s the science?

A recent research article by Ruuska et al. (2012) examined what happened when they took a group of untrained adults and put them through a very specific and controlled aerobic exercise program for 2 weeks.  They tried to control the workouts so they were all at 75% of their max HR and for the same duration.  They also gave them a stress questionnaire to
see what their levels of stress were during this 2 week period.  After the training, they measured a slew of physiological variables including the traditional VO2 kinetics, but also performance variables such as power output.

What happened?

The change in performance variables was a little as no change all the way up to a 40% increase. The level of improvement in both Vo2 and power output was associated with stress level, meaning that the lower “stress” levels they had, the more they improved.

So for all the individuals who had a lot of stressors in their life, had no or very minimal changes in fitness.  They didn’t adapt.

But, that’s not the only study that shows this association.  There have been several studies that have found HR variability, which is used as a surrogate marker for the state of the CNS(Central Nervous System), associated with training response (Tulppo et al. 2003).

More Science

If you comb through the research you’ll start to notice that several stress or stress buffering hormones or markers all relate to adaptation.  For instance, another few studies mentioned in the Ruuska et al. piece showed DHEA-S has been associated with whether there was a training adaptation in elderly adults, with people low in DHEA-S (which acts to counteract stress in many ways) not showing improvement in fitness (Huang et al. 2006).

A study by Lee et al. (2006) found that DHEA-s was related to adaptation to altitude.

Why is this interesting?

Because if we looked at adaptation to altitude for a few of the elites I’ve worked with, they did not show positive adaptations in blood markers or in training if they had high cortisol levels going into and during altitude.  So the higher the cortisol levels, the lower increases in Hemoglobin or RBC mass on several athletes. This was a somewhat common theme, and with some I had to really get creative in making sure to knock down the stress or to up their nutritional support to make sure they could adapt.

Altitude in itself is another stressor (so you get the same generalized stress response) so when you combine it with someone who already has a high stress level (high cortisol) and/or low stress buffering (low DHEA-s) you’ve got to change something or else they won’t adapt.

Just a hunch, but I’ve thought that part of this high/low responder to altitude thing is simply a stress response thing.  So, word to the wise if you go to altitude, check cortisol and DHEA-S or Testosterone before you go!

What does this practically mean?

  1. Pay attention to what goes on outside the training world.  I know this is crazy hard to do in the high school or collegiate world because there is always stress on students, but be aware of it and feel free to adjust if needed as a coach.
  2. Individualize I harp and harp on this concept on this blog, but how much “adaptation reservoir” someone has determines how much work load they can handle.  For elites, what I’d do is look at the various markers in the blood.  Look at Testosterone to cortisol ratios, basal cortisol levels, DHEA-S, etc.  You can also look at someone’s Heart rate variability
    or even something as simple as resting HR or the change in HR from lieing down to standing up.  There are no perfect measures, but the point is, if you see something out of whack, then know you have to adjust.

There are certain athletes who have high stress responses.  It just means that you have to be extra careful in not pushing them over the edge.  Knowing that a high stress response athlete might only be able to handle X, while someone else at the same ability level can handle X+1.  Don’t just give the high stress athlete the increase volume/intensity because that’s what they “should” be doing for someone who races at their speeds.  Realize, that getting continual adaptation is the key, and perhaps pressing too far will lead to no adaptation.

For athletes:

All of the above is important, but also use the information to prioritize your life.  When you’ve got a big training block coming, try to minimize outside stress.  That doesn’t mean live like a hermit, because people have different activities that are stress reducers, but it means try and minimize triggers for stress.

Secondly, look at how you approach practice.  I love the sayings by Renato Canova where he talks about how Africans generally approach training with lower stress and anxiety than their American counterparts.  Realize that getting super anxious and stressed out before a workout could do more harm than good.

The take away message is that stress, whether it’s internal or external, effects the body in similar ways.  There’s only so much we can adapt to.  If you’re outside life gets too complicated, maybe that’s why you aren’t adapting to the workouts?  And for coaches, maybe they can’t do as much as you thought, not because you aren’t giving them enough recovery after, but because you haven’t taken into account the external stressors of life?

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    1. Steve Pero on November 7, 2012 at 2:34 pm

      Phil Maffetone has been saying this for years….balance your life, make a list of stressors. Training is just another stress added to your life.

    2. John on November 8, 2012 at 2:02 pm

      I super interested in reading your 2nd article about "zone training". When you have a chance could you please write it.

      The 1st part was fascinating!

      Thanks so much

    3. Chuck Wall on November 8, 2012 at 4:33 pm

      I enjoy reading your blog and I always learn a lot! You've written quite a bit about HIIT and related training styles. Given that HIIT is a larger than usual dose of exercise stress, what can we say about the timing and amount of HIIT over the course of a season or a year? When other life stresses are active, should we dial back or eliminate high intensity training? Thanks!

    4. andrea dugato on November 8, 2012 at 10:19 pm

      hi steve
      really great article!
      i read it with very interest
      stress it's fundamental, but as everything of life, we don't have to abuse
      balance it's the key, as everything of life!

    5. 13gentj on November 21, 2012 at 2:32 am

      Great article. It'd be interesting to compare how much running can be a stress to how much it can be a stress reliever.

    6. Anonymous on November 24, 2012 at 6:59 am

      What do you think might be the effect of falling/crushing on the ground at the very begining of a marathon race on the final time/ or the glycogen consumption rate compare with "normal" start?

    7. Caiytlin Perry on December 4, 2012 at 2:14 pm

      Exercise is a healthy way in fighting stress. This post made me remember my college admissions counselors , they go for a run on weekends.

    8. on December 26, 2012 at 4:50 pm

      The Stress of Life: How stress can impact your workout. Posted by Steve Magness. The Stress of Life: Adaptation is a fairly simple process.

    9. Anonymous on January 3, 2013 at 9:18 pm

      In coaching amateurs this is the hallmark of what I do. Balance stress. It's not the workouts or the yearly progression, it's managing what they can and cannot handle on a weekly/monthly basis. Optimizing down to the day with their schedules if need be. Makes coaching my professionals easy!!!

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    12. Anonymous on July 19, 2013 at 3:07 am

      Stress has driven evolutionary change (the development and natural selection of species over time). Thus, the species that adapted best to the causes of stress (stressors) have survived and evolved into the plant and animal kingdoms we now observe.

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