Chronic Cardio - How much is too much?


A staggering number of Americans have been bitten by the cardio bug at some point in their lives. Even for those who do not particularly enjoy endurance exercise often rely heavily on cardio as an exercise staple. This is not necessarily a bad thing. Easily accessible from a space and equipment standpoint, endurance training provides substantial cardiovascular benefits, and, the endorphin dump is fantastic.

But how much cardio is too much?

For all the benefits that come along with endurance training, there is a downside of going too far. Once over the 60-minute-ish mark our bodies begin to elevate cortisol and prolactin. Prolactin secretion causes the sex hormones (estrogen and testosterone) to temporarily down-regulate - particularly impacting women since prolactin has a stronger effect on estrogen than on testosterone.  Note: Men and women have both hormones but at different levels as these hormones help produce sex traits. Long bouts of cardio with proper downtime between sessions makes this a nonissue. However, when prolonged workouts are stacked so that there’s not enough time for recovery between sessions, chronically lower hormonal levels are created.

Now imagine the paired effects of prolactin (decreased estrogen and testosterone) with the effects of cortisol – the stress hormone.  Think: Body. Shutting. Down. While the whole picture is more complex than that, elevated levels of cortisol are not desired.  Much like prolactin, higher cortisol levels and its effects are temporary. Which isn’t an issue in our current stress-free modern life!  😉  Jokes aside, most aspects of life include ebbs and flows of stress.  Your body reacts accordingly by adjusting your cortisol levels.  This paired with more cortisol as a result of long bouts of cardio means prolonged levels of elevated cortisol wreaking havoc on your body in the form of poor sleep, nutrition, libido, cognition, weight gain, and the list goes on.

Now that I’ve painted a pretty dark picture - know there’s hope! I am a fan of endurance work. Personally, it is my time to unwind, ground myself in nature, and listen to the wind and my breath. The simplest way to avoid the pitfalls of chronic cardio is to limit it to smaller bouts. Shrink your training sessions to under 60 minutes so that you haven’t overly depleted yourself and can perhaps do two quality sessions in a day. More is NOT always better.

On the other hand, if you are set on the path of chronic cardio because you enjoy long workouts, or you are training for a long distance race, there are a couple of ways you can fight against these hormone changes.  The first step is to plan ahead.

Here are 5 ways to improve recovery from endurance training sessions:

  1. Focus on meditation and/or breath work the day before and the day of longer training sessions.
  2. Increase intake of electrolytes and essential amino acids.
  3. Rest and sleep longer after long training sessions.
  4. Increase caloric intake slightly with well balanced meals to supply your body with hormone and connective tissue precursors.
  5. Enjoy some contrast therapy (alternating between heat and cold) to speed up stem cell production.

Looking for more on recovery, check out Amanda’s blog: Skip Your Workout for more ideas.

Plan ahead with recovery techniques and workout timing so you can make the most of your training.  Do you have a favorite recovery technique?  Share below! Then, get outside and enjoy the process of improving this rediculous machine we call the human body! See you on the trails!



About Author

Ryan Wands

Ryan Wands is an Associate Recreation and Fitness Program Coordinator at the Recreation and Fitness Center with a passion for endurance and mobility training. He enjoys teaching our SAS family intuitive movement while ensuring no one takes themselves too seriously. If you want to talk coffee, obstacle course racing, or metabolism his door is open!

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