CORTISOL – What is it and what does it do?

I’ve had a heck of a time recovery wise since my 12 hour Echo Bike ride and my way of dealing with it is figuring out exactly what my body went through and how I can help it in the recovery process.

Today Im going to give you some perspective on Cortisol and how it effects your body, performance and recovery and how you can help yourself use it to your advantage.

Cortisol is a steroid hormone that is produced by your 2 adrenal glands, which sit on top of each kidney. When you are stressed, increased cortisol is released into your bloodstream. Having the right cortisol balance is essential for your health, and producing too much or too little cortisol can cause health problems.

The sympathetic nervous system, also known as “fight or flight,” is usually what state we are in when we are at work, paying bills, yelling at the dog, cleaning up puke from the dog or twins, cleaning up poop from the cat or twins, having a friendly “debate” with Rach LOL, and, oh yeah, when we TRAIN. Anything that isn’t relaxing and promoting rest is sympathetic.  When we are in a sympathetic state, our body bumps up cortisol.   This is a good thing; we NEED cortisol to optimally handle stress.

It’s well known that endurance athletes are more susceptible to chronically elevated cortisol levels than the general population (Skoluda et al., 2012). Relative to endurance exercise, cortisol rises in proportion to intensity. So during high-intensity training, cortisol production will be supercharged, once again – a good thing. This extra “hit” gives you the boost you need to do those hard workouts. When it comes to lower intensity aerobic exercise, cortisol is still elevated, but not to the degree of high-intensity efforts. But it’s not really the degree to which cortisol is elevated that gives us the problem. It’s how LONG cortisol is elevated and whether or not it’s going down enough between efforts.

Here’s an example. If you do a 30-minute high-intensity training session or a 20 min AMRAP, cortisol will spike high and stay high throughout that 20 – 30 minutes.  But, what about if you go swim 30 minutes, bike for 1.5 hours, and run for another 1 hour at a much lower intensity? OR What if you ride an Echo Bike for 12 hours?  True, your cortisol might not be elevated to the degree that it was in the 20 – 30 minutes of high intensity, but it will still be elevated. Additionally, it will be elevated for 5-10 times as long. Another way to think about it might be: you now have 2.5-11.5 hours less time allowed for cortisol to return to normal levels in your day compared to when you did the high-intensity training for 20 – 30 minutes.

When cortisol becomes chronically elevated, the effect on performance can be dramatic. Here are some reasons why you DO NOT want this to happen.

  • Negatively impacts hormones 
  • Suppresses immune system
  • Impairs recovery
  • Increases risk of injury
  • Breaks down muscle, and stores fat – negatively impacting body composition
  • Increased inflammation
  • Increased fatigue
  • Negatively impacts bone health and ligament health
  • Decreases quality of sleep
  • And more!  But hopefully, that’s enough.

This is literally my life right now! Not only did I go through 4 months of 3+ hours of training 5-6 days a week, I ran a business, I have 3 kids, 2 of which are 2 years old. I have a house we built and are trying to sell, we moved during this time and I moved the WHOLE house by myself. I have 0 actual rest days a week. I never sit and never relax. I got bronchitis, the flu and probably some version of Covid during training. Now my body is busted and blood work has been a mess and its time to pull myself out of this HOLE.


Prepare your body

Evidence shows that cortisol responds more favorably during and after exercise in well-trained individuals (Popovic et al., 2019).  It might seem counterintuitive, but you NEED those long, hard efforts.  Keep doing them, but pay extra attention to the other strategies in this section.  On the other hand, if you are CURRENTLY experiencing several signs from the list above, it’s time to back off and take rest.  In this case, a couple of weeks off from training is probably a good idea. 

Meditation/mindfulness routine

Give meditation a try.  There are tons of great apps and resources available to help you get started.  Research shows that meditation results in reduced serum cortisol (Turakitwanakan et al., 2013).  Remember, like anything, meditation takes practice to become proficient.  A deep breathing routine has also been shown to lower cortisol (Perciavalle et al., 2017).

 Get enough sleep

 Sleep is essential for too many reasons to mention, endurance athlete or otherwise.  Obtaining adequate sleep is critical for keeping cortisol levels in check (Leproult et al., 1997).

 Stay hydrated

Make sure you’re staying hydrated both during training and in daily life.  When you’re dehydrated, cortisol rises (Maresh et al., 2006).

Make time for rest

Always PLAN for rest and relaxation.  If you don’t make it a priority, it probably won’t happen.  A training program that incorporates periodization can be useful in this regard.   

Have Fun!

Doing things that make you happy is one of the best things you can do to lower cortisol (Steptoe et al., 2009).  Laughter, spending time outdoors, and taking up hobbies will all prove beneficial

Eat a healthy diet

What you eat can very much influence cortisol.  Of course, what you eat very much depends on your particular diet.  We believe there are no “one size fits all” diets for ultra-endurance sport or otherwise.  Use common sense and be mindful of what you’re putting into your body.

 Recovery after training

 Proper recovery after training is essential for keeping cortisol levels from creeping up. Take advantage of the 30-minute recovery window by immediately consuming a drink or meal with a 3:1-4:1 carbohydrate to protein ratio.  This is most easily done in the form of a rapidly digesting drink. Ingesting adequate carbohydrates during long efforts and immediately following all training sessions keeps cortisol in check and ensures optimal glycogen replenishment. 

I hope this helps shed some light and maybe help you pull yourself out of a rut, Im curently in a rut and its not fun but time and the right path will lead me to better days.

Coach Dan