Psychology Today’s “Exercise and Fasting Linked to Brain Detox” & my exercise class

My colleague, Chris Palmer, MD, recently posted to his Psychology Today blog.  And then thist happened…

So I was at my Friday HIIT boot camp. The topic of “Exercise and Fasting Linked to Brain Detox” came up. Chris’s article highlighted how fasting and exercise improve brain health. People got excited.  We all loved that our exercise efforts were neuroprotective while also increasing our fitness level.


Then the questions started. Wasn’t it always known that exercise was healthful for the body? What about exercise frequency and intensity? Monica asked: “What about intermittent fasting?” I’ll try to answer these questions and then open up the discussion. .

HIIT exercise fasting metabolic brain health happy ladies
These are my beautiful exercise peeps. Clockwise from bottom left. Monica, Ruth, Struggle (our beloved trainer and taskmaster), me, Kerstin, Carol and Atia.

What exactly did the Harvard study show? And why should we care?

Here’s the study Chris wrote about.

The skinny on the implications about fasting and vigorous exercise? Each independently improve the cellular cleanup process that allows cells to stay healthy.  Cellular debris is toxic when it remains inside of a cell too long. In brain cells, this toxic debris is what gives rise to scary neurodegenerative disorders. Some examples are Alzheimer’s, ALS, and Parkinson’s. These are debilitating diseases we all obviously want to avoid.

So exercise and fasting are preventative measures to avoid disease.  Yay!

But what kind of exercise?

But what kind of workout and what kind of fasting.  Let’s unpack exercise first.

The study reported that just 9-11 minutes of vigorous exercise makes a difference. This is what we in the bootcamp world know well as HIIT or high intensity interval training.  But, you don’t have to be a bootcamper to benefit. That’s because HIIT is well known to be a scalable workout that people of various levels of fitness can do successfully.  You go hard, as defined by your level of fitness, then you rest. Then you repeat at designated intervals, for example 30 seconds hard, 30 seconds rest. It is the repeat part that’s key!  This study used HIIT, what isn’t known yet is what other types of exercise may also help cellular detox. More research is needed.

Did you get that?  9-11 MINUTES not hours, days or years.  That’s like the exercise version of flossing. A little effort done repeatedly can produce outsized health benefits.

Next comes the “Wasn’t this already known” question.  Yes, we already knew exercise was healthy. But this study found actual cellular evidence of change in an intracellular chemical, cAMP.  This change accounts for this particular benefit of exercise.

Fasting and brain detox

Let me start with the good news. When people think about fasting they think it involves suffering, hunger and discomfort. Understandable. We are talking fasting-lite here. The Harvard study found that a 12 hour fast did the trick in improving cellular detox. 12 hours!  So this “fast” means stop eating at 7, after dinner, and eat again at breakfast at 7. So this is fasting without ever missing a meal!

That’s what the study reported.  Now for the fasting related questions.

Fasting questions

Let’s start with the popular topic of intermittent fasting, or IF. The study’s 12 hour fast interval would be the mildest version of IF, a 12-12. That is, in a day, eat during a 12 hour window, fast during the other 12 hour window.  Also remember, IF is for adults, never for children, as their dietary needs are different.

There are more intensive versions of IF. I’m talking here about 16:8, 24 or 36 hour fasts, and alternate day fasts to name a few. A quick Pubmed search reveals recent articles about fasting in the medical literature. One review article proposed benefits of this way of eating while highlighting areas for future research. The article in Aging Research Reviews says that IF can help with weight loss while improving many health indicators.  For example, improvements in insulin resistance and decreases in cardiovascular disease risk factors. They report cellular and molecular changes that improve health. This includes activation of pathways that improve mitochondrial health. (Remember from high school, the powerhouse of the cell, and therefore you.) Also, these activated pathways repair DNA  and regenerate stem cells. Now all of these areas need randomized controlled clinical trials to validate them. But it sounds like this is a helpful eating pattern that can be used to improve health and prevent disease. And, back to our Harvard study, it did find a validating bit of data to strengthen this idea. Research is already being done and more needs to follow.

In the meantime, I do three 24 hour fasts each week.  I’ll write about my experience in a future post.

I hope this answers some the excellent questions generated by the gals in Friday’s bootcamp!

P.S. Did you notice my Ketofest 2018 tee shirt? That’s where I met my brilliant co-founder Cecile Seth!  You can read more about How my mother’s suffering spurred me to find keto.


Mattson, M.P., Valter, D., Longo, M.H. (2017). Impact of intermittent fasting on health and disease processes. Aging Research Reviews, 39, 46-58.


Nothing in this article is intended as medical advice. Anyone contemplating fasting, the ketogenic diet, a particular form of exercise, or any intervention as a treatment for an illness is urged to seek medical help from a competent medical provider trained in treatment of the underlying condition as well as the specifics of the proposed treatment or intervention. No healthcare provider-patient relationship is created by this article, or by any responses to comments posted in this forum by Christie Barnett, APN or Chris Palmer, MD.

More on the ketogenic diet – mental health – metabolic connections

Christie Barnett, APN

Christie is an Advanced Practice Nurse with over 35 years experience working with people in mental health care. She currently has a private, outpatient psychotherapy practice in Millburn, NJ. You can follow her on Instagram at keto.nj

2 Responses

  1. Emmy McBride says:

    Christie thank you for this information. I am so excited to pass this on to my sister. Such hopeful research!

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