CrossFit Longevity Experience

Dr. Jason Fung: I recently gave a presentation at the CrossFit Health conference in Madison and met lots of great people. I had a great discussion regarding cancer with Dr. Thomas Seyfried and caught up with Gary Taubes at lunch. I also met a couple of guys, Mike and Craig who are helping to make a dent in chronic diseases, and asked them to share their story here. Mike sends a free daily email to a fasting support group, and crazy guy that he is, wakes up at 1 am to get it done. You can email him at to join.

Mike and Craig:

In the past, I practiced mainstream general internal medicine, following guidelines for the treatment of acute and chronic diseases.  Nutrition and exercise were not the work of doctors.  We prescribe medication when patients “inevitably” fail.  We manage chronic disease but don’t improve it.

Observation led me to question the “hyperglycemia causes the ills of Type 2 Diabetes” paradigm.  Patients with fatty liver and “idiopathic neuropathy” were obese with normal glucose levels, often with a family history of diabetes.  They developed diabetes (hyperglycemia) years later.  Then we declared they had “diabetic” neuropathy and fatty liver.   I suspected something other than high glucose was needed to explain this phenomenon of disease preceding cause.

We started to discuss Metabolic Syndrome but insulin resistance wasn’t part of the discussion. That language came years later.

After 30 years of group practice and mainstream medicine leadership, I opened a concierge practice in 2011.  Patients appreciated the attention and access, but I wasn’t any better at improving my health or the health of my patients.  I had the chronic disease of obesity.  I later realized I am insulin resistant.

My carotid intima media thickness (CIMT) scan confirmed my atherosclerosis, which was developing in spite of statins.  My obesity worsened as I ate a low fat, high carbohydrate diet.  I added CIMT measurement to my practice, addressing the findings with standard approaches and uninspiring results.

In 2012, I was challenged by Mike Suhadolnik, a past neighbor and trainer who had benefitted from Crossfit.  Mike had the vision to transform fat doctors and other health care leaders to start a movement to fix community obesity.  He called it Doctors Get Fit.  Little did we know where it would take us.

I weighed 235 pounds and measured with a 35% body fat using a DXA scan.  I changed to eat Paleo and was thrown into Crossfit as the first client of Doctors Get Fit.  I lost 65 pounds, 12 inches off my waist and dropped to 19% body fat.  I was never fitter or happier.  Thus began the Crossfit Instinct Longevity class for older individuals who wanted better health.

I became an authentic and inspiring example whose advice about nutrition and exercise became more compelling.  My patients joined me as we got off the carbs and off the couch.

In late 2013, I discovered the Bale Doneen Method.  It offered a life free of heart attack and stroke.  I was convinced by the evidence-based approach that optimally addresses root causes of arterial disease.  Insulin resistance is called out as a ubiquitous root cause in the inflammatory and dyslipidemia milieu causing atherosclerosis.

We implemented these recommendations in our patients.  It challenged mainstream orthodoxy but got inspiring measurable results for my patients.

I opened my practice to consult with patients with atherosclerosis beyond my concierge practice to reverse this chronic disease.  We created The Center for Prevention Heart Attack and Stroke.  My partner in the care of patients with chronic disease is Mike and Crossfit Instinct Longevity in Springfield, IL.

Chronic disease is “diabesity.”  It is increasing because humans are suited to thrive in an environment of scarcity. That environment has been replaced by ubiquitous and addicting processed food that is fueling the epidemic of chronic disease.

We learned from clients who sought improved health.  The Crossfit nutrition prescription of “vegetables and meat, some fruit, nuts and seeds and good fat” coupled with “constantly varied functional movement with high intensity” achieved inspiring results.  This developed into the Longevity class to enable those with chronic disease to benefit from Crossfit.

Mike discovered the compelling benefits of time restricted feeding and intermittent fasting.  He offered this to Longevity members and others. At The Center for Prevention, we embraced it and recommend it.  We encourage intermittent fasting and time restricted feeding while getting off the carbs and off the couch.

Many are unable to commit to Doctors Get Fit or Crossfit Longevity due to expense or time.  They are, however, willing to fast, eliminate processed food and come to a monthly meeting.  They are encouraged to eat only meals of real food and to strive to eat only within an 8 hour window daily. They break their fast with protein and fat, not sugar.  They lose fat quickly and sustainably.  They are inspired by those who succeed.  They inspire others.

High intensity exercise is optimal.  Most of our measured patient/clients are not Crossfitters.  However, Crossfitters get the most dramatic improvement.  The results from the synergy of real food, intense exercise, resistance training and the community of support is second to none.

BioImpedance Analysis provides quick, objective and compelling data to patients with chronic disease.  Motivated by the data, we change behavior.   We Measure, Motivate, reMeasure to Maintain Momentum:  The healthier M&M’s.

After baseline measurement, we remeasure at 2 weeks and then every 2-4 weeks.  Measurement of percentage body fat and visceral fat reveals much more than the scale and weight.  Watching fat disappear inspires behavioral hard wiring.

Fasters receive a daily email message with consistent advice to avoid sugar and processed food and to eat in an 8 hour window while drinking water throughout the day.  Each email comes with a new motivational message.  While some “do Crossfit,” it is not mandatory. Fasting and the support is free, but we encourage participation and sharing.

2528 pounds of lost fat and 487 pounds of lean body mass gained in the past year represents all who have been measured more than once on our BIA device.  We are going to dig deeper to separately analyze those who are Crossfitting, Fasting or both.

We believe that the principle of Fasting coupled with detailed measurement, accountability with daily inspiration and mutual support is the secret to our results.  Exercise augments nutrition, but it isn’t the core ingredient of success.

We are excited to share our results and look forward to comments.  We are happy to engage with like minded providers to push this successful paradigm to replace the unsuccessful current mainstream approach to chronic disease.

Craig A. Backs MD

Executive Medical Director

The Center for Prevention

Springfield, IL


Michael Suhadolnik

Level 2 Trainer

Crossfit Instinct Longevity and Doctors Get Fit


2018-08-08T10:27:29-04:006 Comments

About the Author:

Dr. Fung is a Toronto based kidney specialist, having graduated from the University of Toronto and finishing his medical specialty at the University of California, Los Angeles in 2001. He is the author of the bestsellers ‘The Obesity Code’ and ‘The Complete Guide to Fasting’. He has pioneered the use of therapeutic fasting for weight loss and type 2 diabetes reversal in his IDM clinic.

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SandyJoey Dorwart CraneDanadr amardeep garg cardiologistJonathan Backs Recent comment authors
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My question is after these changes has the Dr had a new scan that indicates either a halting or even an improvement in heart disease?

Jonathan Backs

Hello Jeff, yes we regularly retest people in the program to make sure that the prevention plan that we have implemented is working. We are able to measure to make sure we have stopped the progression of disease and are reversing the damage. See the link below to see some of the examples

dr amardeep garg cardiologist

no doubt intermittent fasting is excellent tool for diabetic cure. but body works 24 hrs. bile is getting produced continually. all our body secretions are also getting secreted though at a lesser date. isn’t this will predispose to cholelithiasis


Why would a gallbladder develop stones from doing its job?

Joey Dorwart Crane
Joey Dorwart Crane

Hello! I am a 36 year old male that weighs around 150-155 and 6’1″. BMI about 20. I’m very fit, exercise and eat very well. Plenty of whole foods and healthy fats. My mom was recently diagnosed with glioblastoma. She is very thin and cannot stand to lose any more weight. As two thin people, my question is this: how can I incorporate fasting as a cancer prevention tool? I understand she is a much more complicated case. So let’s start with me. She is very hesitant about keto and fasting. Thank you very much!


Joey look up Thomas Seifried’s work on Cancer, and using ketosis to starve the cancer cells. So many times due to the muscle wasting in cancer too much protein is recommended, which will turn to glucose (gluconeogenesis), and this feeds the cancer cells. Also, some intermittent fasting can be used to stimulate autophagy (body eating it’s own bad cells, i.e. cancer cells), or even a fasting mimicking diet (see Valter Longo’s work), if you are concerned about prolonged calorie restriction.