Happier Blood Sugars During Your Workouts

Are you feeling that the good that comes from working out is often watered down by an undesired, exhaustive blood sugar reading?

I feel you.

Working out with type 1 diabetes can be discouraging.

Despite my love affair for staying fit & active, there are some days diabetes makes its (uninvited) presence loud and clear in the most inconvenient ways. 

A mid-workout low or post workout high are both frustrating scenarios you can find yourself stuck in.  

But despite the unpredictability that this disease brings, it is possible to greatly reduce the interruptions of high and low blood sugars. After much trial and error, I have discovered a really solid routine in bringing some PEACE back into my workouts: 



Timing; Early AM/Fasted Workouts

Working out fasted (no food), removes the stress of excess active insulin from your day of eating.

I used to workout after work (around 6pm-7pm), and I would always have to be super cautious of my dosing’s earlier in the day. I could never be fully present in the class because the risk of a low was always weighing heavily on my mind. If my dose(s) from earlier in the day weren’t perfectly calculated, my workout would be effected by a low—guaranteed. No food = minimal active insulin to sabotage your workout! 

With all of that said, I still bolus pre-workout. I typically (aim to) wake up around 100mg, and 2 units of insulin when I wake up covers:

Dawn Phenomena—Morning hormone surge causes you to be more insulin resistant and have higher blood sugars.

Liver Dump—My workout (Crossfit) consists of strength training & HIIT, i.e. anaerobic exercise. Aerobic exercise typically causes your blood sugars to fall, while anaerobic causes a spike due to your liver dumping glucose. 

Aerobic exercise examples: walking your dog, cardio machines, spinning, running, swimming, hiking, aerobics classes, dancing, etc. Aerobic exercises can become anaerobic exercises if performed at a level of intensity that is too high but these exercises typically don't require insulin, and tend to lower blood sugars. 

Anaerobic exercise examples: HIIT, sprinting, weight training, interval training, etc. During intense exercise periods your body breaks down glycogen (stored glucose) with the expected rise in blood glucose levels. These style of workouts raise the blood sugars and require insulin (increased basal%, increased bolus). 


Consistency is KEY when it comes to managing your blood sugars. 

Just like changing your food selection too much on the daily, frequently changing when you workout and the type of workouts you do will leave you feeling frustrated. 

“Consistent action creates consistent results.” …..for the most part :) Type 1 diabetes has its own agenda sometimes (despite all intentional, disciplined effort). 

This doesn’t mean you can’t try new things. It just means, find something that works for you, and stick with it 80% of the time to increase your peace and see balanced, controlled trends in your blood sugars. 


The best way to see trends in your blood sugars is to log—keep a small journal just for your blood sugars.

Hormones, stress, certain foods, life events, etc. each play a role in your blood sugars.

Sneaky culprits can be brought into the light a lot easier when we have some data to look back onto. 

Example: I have found that leading up to my cycle, like a week before, I am super resistant to my bolus in the morning. My typical 2 units do not cover my workout, and I trend in the 200’s. I am still fine tuning this (adjusting basal, increasing bolus), to figure out the best solution, but logging and taking notes has helped so much in this process. 


Who knew so much evaluating, calculating, & stress went into working out? 

Some days when I am in a workout class I look around and feel a little envious towards those who have one thing on their mind: the workout! 

With that said, I have come a long way with always fearing and correcting lows. Now, I am mainly learning and understanding how to master the random highs (pesky hormones). 

If working out is something you don’t do, I encourage you to start!

You’ll get happier.

Your immune system will be stronger.

Your mind will be clearer.

You will sleep better.

You will feel more confident.

Your blood sugars will improve.

Your insulin resistance will decrease.

….the list goes on & on!

Working out has been my saving grace for my mental and physical health and I could not imagine not starting my day with it.

In summary, don’t let this disease limit you from things that nourish and serve your body.

--If you feel fearful incorporating workouts, start with a morning walk or light jog. Working out fasted will decrease yours fear and allow you focus on the benefits versus the risks. 

--If you keep spiking from a workout, you are likely performing an anaerobic exercise and your body is breaking down glycogen stored in your liver.  Increasing basal and/or bolus will support in counteracting this rise in blood sugars. Log, stay consistent, & try to workout fasted so you can focus on the spike (versus low) and discover a dosing adjustment that works for you. 

--If going low during your workouts is a frequent occurrence, there could be a few factors at play, but the main one is likely having too much (insulin) bolus on board. Stick with lower carb (or fast) pre-workout. The beauty of working out first thing in the AM is that your body is primed to burn fat for fuel instead of glucose; this GREATLY decreases your risk of a low.

Seek guidance from your endocrinologist or diabetic counselor to support you with your personal dosing needs & requirements.


Other good reads:

5 Tips to Better Exercise With Type 1

HIIT Training With Type 1

How to Safely Exercise With Type 1