John – First off, I want to start out by saying I’m a big fan of your site, knowledge, etc.
I’ll be brief so I don’t waste your time, but I have a unique question that I think you might be able to answer.

Long story short, a few years I was diagnosed with Type 1 Diabetes (even though I was super lean). I then naively and liberally started insulin shots on an endocrinologist’s recommendation and ballooned up over 60 pounds. Then I found CrossFit and then about a year into CF, I corresponded with Robb Wolf and went ketogenic (sub 30g carbs daily)- it was truly life saving. I lost 30 pounds, got off all of my insulin, etc.

But currently, I’ve stalled out and I am about 220 pounds with about 15% body fat.

I’ve read up on the iso-caloric recommendations and am really want to try to move the lion share of my carb intake to pre/post workout. But here’s the conundrum/question I have (that my endocrinologist can’t or won’t answer):

Because I am diabetic, my blood glucose spikes during workouts and eating only compounds that, but it always comes down very quickly after the workout.

I say all of this to ask, if the whole goal is to keep my blood glucose low and level, is it a bad idea (for me) to eat carbs pre/post workout? Meaning, am I playing both ends against the middle and screwing the benefits of insulin mediated glucose disposal?




While I am not a doctor and never claimed to be, let me take a stab at it.

As you know, Type 1 diabetes, it is an autoimmune disease where the beta cells of the pancreases are damaged or destroyed and looses the ability to produce insulin.

The fact you are type 1 and able to get off all exogenous insulin means your beta cells are damaged but LIKELY able to produce a minute enough amount of insulin to keep your basic functions working. A ketogenic diet is often helpful as the ketones are backfilling what glucose was generally providing previously, but largely sparing you the need for exogenous insulin.

If your body produced no insulin, you would experience what 100 years ago was called the “wasting disease” where no matter what you ate, ketogenic or not, you wasted away to nothing and eventually died. Good thing this is not the case and you are able to live a normal life free of daily insulin.

The issue with glycolytic heavy training systems like CrossFit is they are extremely hard on the CNS which results in increased stress with a massive cortisol release – think fight or flight. The body spikes blood sugar in response to cortisol. However, there is thing called non-insulin mediated glucose uptake where if blood sugar spikes you can use exercise to bring it back down.

I used a glucose meter for a few months and whenever I would eat something that would spike BS, I would jump on my Assault Bike for 20 minutes and it would fall. One night I ate Chinese food and was having trouble driving because my eyesight was so poor. Turns out when blood sugar rockets it can damage the blood vessels in the retina and impair vision.

I suspect if we could see your blood sugar in real time – a few minutes into the workout it would fall through the floor only to have it rebound. I believe that rebound is what you are seeing.

Robb Wolf wrote a great post on CrossFit and Type 1 where he discussed “mapping”. This is where you test your blood sugar is response to different workouts.

“Start the intensity low (this may mean stepping back a little…you can do it) and mapping your blood glucose response after various WOD’s. How much does Fran elevate your numbers? Helen? Filthy Fifty? You need to build an inventory of what WOD’s do what to you. Then…hope for the best, because every time you do a WOD like these things are different. And you may have a dramatically different response than you might have guessed…hence, recommendation number 4.”

In past, I had a type 1 client and I prescribe a steady diet of heavy weights and mild aerobic training with a heart rate monitor. Remember the intensity (not the percentage type we use when talking about 1 rep maxes) you exert during a glycolytic workout is what causes hepatic glucose release.

If your goal is to stay off all exogenous insulin, then I would live a life that keeps blood sugar in check – sleep, lift heavy weights with more than adequate rest between sets, mild aerobic work coupled with a ketogenic diet.