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Cortisol Output: HIIT vs. Steady State

I’m trying to manage chronically high cortisol levels and I can’t figure out which type of cardio I should focus on. There is a big disconnect between what I read and what I have actually experienced.

Everything I’ve read says steady state will elevate cortisol worse than HIIT, but I’ve had several instances of performing HIIT where I felt so wired afterwards that I couldn’t sleep. I never really had cortisol issues until I started sprinting several times a week for several months. Conversely, I did steady state for years without any negative side effects.

Anyone have any thoughts?

Good question! I think the proof is in the hormonal pudding, so to speak. Whatever the studies say about cortisol production in other people, it appears your (OP’s) body produces more from HIIT than LISS (low-intensity steady state.) My body seems to respond similarly to yours; a half-hour on an elliptical or a few mile jog, even if somewhat intense and tiring, leaves me feeling upbeat and ready for more the day after. HIIT, on the other hand, zaps me if I do it frequently when also lifting.

I’m glad to hear someone else feels the same way. I think maybe all the “LISS raises cortisol” hype assumes people are running 5 to 10 mile distances. I run 3 miles at a moderate pace. A good 400m sprint workout can last longer than it takes to run those three miles.

Having a very quick look at Google scholar it looks like cortisol levels collerate pretty well with intensity. As in cortisol increases with intensity, which is kinda what you’d expect. I don’t know where the idea that it’s the opposite came from.

Chronic Elevate Cortisol

How did you come to that conclusion? Did some lab work indicate that? Or are you just guessing?

The Vilification of Cortisol

Cortisol is NOT the evil villain that it has been portrayed to be.

Acute elevation in cortisol increases the use of body fat for energy (burns body fat), increases bone density and trigger inflammation that is necessary for healing.

Inflammation has also been unjustly vilified. Acute inflammation is part of the healing and recovery process with exercise.

“The poison is in the dose”

Large doses of Steady State or HIIT over a period of time eventually lead to Overtraining, which produces a chronic elevation in cortisol.

Overtraining is a symptomatic condition brought on by a poorly written and executed training program.

Epinephrine and Norepinephrine

Any type of high intensity training like HIIT or Metabolic Condition Training jacks up your epinephrine and norepinephrine, adrenaline.

It is somewhat like taking amphetamines.

With that in mind, “Would you take an amphetamine before going to bed?”

This is a Neon Sign

You just stated your issue is due your chronically overtraining for months.

Common sense should be applied. If something is creating a problem for you, WHY continue to do it?


This is defined as short term stress that is place on the body.

A well written progressive exercise program incorporates Over-Reaching into a Periodization Training Program Cycle.

The progressive program increases the loading and stress over a number of weeks. In the final week of the program, exercises are pushed to failure or near failure.

After the final week of high intensity is completed, the intensity of the next Periodization Training Cycle is dropped down, allowing recovery to take place.

The new Periodization Training Cycle is then progressively increased over a number of weeks ending in going to failure or closet to it.

General Adaptation Syndrome

Periodization Training is based on Over-Reaching. Short term stress is place on the body with an exercise program, making it a little weaker.

It is followed by backing off and allowing the body to recovery.

The body responds and adapta by increasing strength.


This occurs when Over-Reaching has taken place and you continue to train hard and push it without allowing recovery to take place; over a period of months, which you have.

The end result is a decrease in strength and not feeling well.

The length of time require to recovery from Overtraining has to do with…

“Wound Healing”

The greater and longer the trauma to the body, the longer the recovery time required.

Think of it like this. You recover from a small cut on your finger fairly quickly.

Major surgery is much greater than a small finger cut, requiring a greater recovery time.

The same applies to Overtraining.

Months of Chronic Overtraining is going to require some recovery time.

Continuing to push yourself with sprints is just going to make thing worse.

Take Home Message

  1. Chronic Overtraining is the problem.

  2. Continuing to push HIIT weekly sprints will exacerbate your issue even more.

  3. To resolve the issue, you need to follow a Active Recovery Program.

Active Recovery means a light, easy exercise program. This type of program is more effective than Passive Recovery (sitting around doing nothing).

Keny Croxdale

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Your a tard if you think something like sprinting twice a week causes overtraining

The issue issue isn’t ONLY sprinting twice a week.

The issue is the accumulative effect in combining it with other training.

Kenny Croxdale

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@KennyCrox is correct. The issue lies in your volume and improper programming of the energy systems. The majority of these HIIT protocols, that you find online are slopped together, with a mish-mash of intensitiesXwork:rest ratios and call it conditioning.

While, your muscular system may be recovered, your nervous system may not be. High intensity activities, like sprints or maximal effort deadlifts put your nervous system in a sympathetic dominance state. Optimal recovery doesn’t take place, untill your body returns to a parasympathetic state. Google “The Parasympathetic Secret” on elitefts for a better understanding of this.

I understand that, I would say for the average in shape person, someone could handle 5-6 session a week of ATP/CP energy system sessions weather thats HIIT or weight training and do 3 or 4 LISS cardio session causally.

I compete at a high level for my sport and put in a lot more than that in a week with skill sessions and such

Overtraining is largely an overused term, you would have to do some pretty terrible things to your mind and body for it to happen

Cortisol is not necessarily bad. It is important in the myelination of nerve cells. Meaning if you want to improve at anything from passing a test to squating 500 lbs. you are going to need cortisol to do it. When you stress yourself you release cortisol in order to myelinate the neurons so that when you experience the stressor again your nerves will process the signals at faster rate. The problem comes when there is a negative stressor and those signals are processed faster every time you experience that negative stressor.

So it is very possible that cortisol released from the stress of training may facilitate improvements in exercise performance, but cortisol released from a bad day at work may facilitate the negative aspects of having a bad day at work.

Of course, much of this is still being researched so no one knows anything for certain at this point.