"To dose, or not to dose pre-workout?" That is the question.

Have you ever experienced a HIGH blood sugar POST workout?

Experiencing low blood sugars during (or post) workout tends to be the typical experience for a Type 1 so this concept may seem a tad foreign. 

The idea of needing insulin prior to a workout can seem like one is just asking for a random low--which can be true, it just depends on the type of workout (and a few other variables)! 

Physical activity can actually affect blood sugar in multiple ways. 


Example #1: Aerobic exercise. i.e. jogging, hot yoga, elliptical, cycling. 

These types of exercise raise your heart rate for an extended period of time which consequently will generally trigger your blood sugars to fall. This type of exercise uses glucose primarily for fuel. 

A blood sugar drop is triggered due to enhanced insulin sensitivity and accelerated glucose consumption by muscle cells. 

Tip: You can reduce your insulin dose, increase carbohydrate intake, or a do combination of both prior to this style of workout.


Example #2 Anaerobic exercise. i.e. HITT, Crossfit, Weight Training, etc. 

This style of exercise is what can cause a SPIKE.

Trial and error have been my BFF for this because I start my day with Crossfit first thing in the morning within minimal active insulin & food in my body. 

I would wake up with an amazing 84 reading, head to Crossfit, and check my blood sugars post workout and they would be 200+!

Blood sugar rise during anaerobic exercise is caused by a surge of stress hormones that oppose insulin’s action and cause the liver to dump extra sugar into the bloodstream. 


So now what? 🤔 

Think like a pancreas! 

In higher intensity/stress environments, we need extra insulin.

In a working, healthy pancreas, it knows what to do: it churns out some extra insulin to offset the “fight or flight” response. This is due primarily to the stress hormone production or “adrenaline rush” that accompanies this style of workout. 

But not mine. 

And not yours (if you're Type 1). 

Okay, so now what? --- Trial & error. Keep a log journal. Consistently monitor blood sugar levels and look for trends.

My routine typically looks like this:

1. Wake up, 

2. Check my blood sugars,

3. Dose around 1-2 units (depending on what my number reads)

4.  Eat 15-20g of carb 20 minutes before my workout session. ( i.e.1/2 sweet potato, 1/2 banana, or protein shake with banana). Carbs + small insulin dose mixed with high intensity exercise will turn off your livers sugar tap!


Despite my efforts, I still experience a random high here and there but they have been drastically minimized and better controlled. 

So....."to dose, or not to dose pre-workout?" If you are doing aerobic exercise you shouldn't need to, but if you are doing anaerobic training, dosing is likely necessary to avoid the spike (especially first thing in the morning).

Please remember, there is no exact science in managing this disease. There are countless variables that affect our blood sugar levels, i.e. hormones, anxiety, protein, fat, weight gain, medications, stress...... and the list goes on but we will save these for a future post!

Closing thoughts:

1. Minimize high carbohydrate meals for optimal control and blood sugar balance.

2. The less you need to inject (stick with lower carb, nutrient dense meals), the less variability you will experience!

Do you have any tips or tricks on how to avoid lows and/or highs during your workout routine?