How Exercise Timing Impacts Your Blood Glucose

00:00 Intro
00:41 Experiment Design
01:12 Day 1 No Exercise
02:13 Day 1 Interpretation
04:56 Day 2 Exercise then Smoothie
05:34 Day 2 Interpretation
08:35 Day 3 Smoothie then Exercise
09:09 Day 3 Interpretation
09:56 Discussion
10:54 Conclusions

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Hosting, Research, Writing & Post-Production by Lara Hyde, PhD

Music & Video Production by Robbie Hyde

The information in this video is not intended or implied to be a substitute for professional medical advice, diagnosis or treatment. All content, including text, graphics, images and information, contained on or available through this video is for general information purposes only.

Additional Footage
Photo by Ave Calvar Martinez from Pexels
Dance footage from Urbanity Dance Creative Class performance April 2022, choreographer Danielle Pastuszak

References

Our bodies have developed a beautiful, dynamic system to maintain glucose levels, whether you’re hiking a mountain, doing a dance, or snuggling a poodle. It all relates back to supply and demand, what glucose is coming in, what do we have in storage, and what is the demand of the system? Eating carbs supplies the body with glucose. Exercise demands glucose as fuel. But here’s the thing - that timing of supply and demand impacts our metabolism, and manipulating that timing can impact health. To get some data on how exercise timing impacts blood glucose responses, I’ve designed a little n of 1 experiment. Each day, I’ll drink an identical smoothie for breakfast. One day I’ll refrain from exercising before or for 2 hours after my smoothie, one day I’ll exercise immediately after my smoothie, and the other day I’ll exercise immediately before. I’m using a continuous glucose monitor which measures a proxy of my blood glucose every 5 minutes. The goal with today’s set up is to get a sense of my baseline postprandial glycemic response. Glucose is delivered to cells through the blood, but this glucose can’t just diffuse directly into cells. When GLUT4 is in the membrane then glucose slides through to get into the cell, but when GLUT4 is absent then glucose is trapped outside. GLUT4 isn’t always in the cell membrane. Often it is stored in little balloon-like vesicles inside cells. Inserting GLUT4 into the membrane requires a signal from the hormone insulin. The goal of insulin is to lower glucose levels by signaling cells to insert their pre-made GLUT4s into the membrane. When I start exercising, we actually see my glucose level rise because my muscles required extra fuel. The muscle started off by using glycogen - a whole bunch of glucose units all bound together. It turns out that contracting muscles causes those GLUT4 doorways to get inserted into the membrane without any help from insulin, allowing the muscle to take in glucose from the blood. This is called insulin-independent GLUT4 translocation - because GLUT4 is getting inserted into the membrane without insulin’s help. So that’s what we see here, we see my glucose level dipping a bit because my exercising muscles are taking in glucose from the blood. Since this exercise was pretty intense, it caused the stress hormone adrenaline to be secreted[6]. Adrenaline triggers the liver to breakdown some of its glycogen and release glucose into the blood. That’s what we see here with the rise in my glucose level during exercise - my glucose was rising because the liver was providing fuel for working muscle.

[racquinox]

I'm so happy to have found a channel talking about health from a scientific perspective rather than fads and conspiracies. Thank you 🙏

[humannutritionist]

Finally a doctor that is actually talking in their area of expertise, and not some half baked m.d. misrepresenting their credentials for the sake of $. I've subscribed, with sincere thanks for your philanthropic resource.

[scotthelsel]

Thank you for adding the graphics. It helped me understand how the mechanism of Glut 4 works. Great explainer on how exercise can immediately impact your blood sugar!

[jonathanmein]

Very well done and informative! Keep it up, Dr. Lara!

[sony]

I've been following how food impacts blood sugars for years and this video so far is the best explained video about. Thank you!

[kaekillay]

I've been searching for a clear explanation. Now I've got it. Thank you soooo much. All the best ❤

[pavelzin]

I knew all of this, but the way you presented it here is really great. It really shows you know what you are talking about. Thank you.

[jstanley]

You answered so many of my questions in one video. Thank you!

[kausalyanallainathan]

Thanks for this video. Good explanation. For me when I do an intense workout after my meal the curve is stable but it goes up after an hour and stay up for more than 2 more hours.

[michaelmurphy]

Great job. Thanks for putting a little science into my beliefs.
I was diagnosed with Pre-diabetes and I am trying to reverse it.

I have changed my diet, meditation daily, and use supplements.
I try to have 1 cheat meal a week. I walk 30 minutes to the restaurant and 45 minutes after. It seems that my hypothesis might be right about exercise and blood glucose.

[bjmorgan]

This is very informative. I learned about the Glut4 and how glucose get into the cell. I love your demonstration.

[Upperwestsidemolar]

Thank you!! I’ve been struggling with hypoglycemia post exercise for some reason, and this is helpful in my mission to figure out how to prevent this!

[kalaivignesh]

I'm a computer science background person, i loved your explanation and the content you produce...
I saw digestion foundation and it's interesting and metabolism foundation too.. it bit sciencey because of chemical reactions...but it would have been much useful when I'm from a science background person...trying to learn about my body through your videos...thanks for your knowledge ❣️

[ChicagoJ]

This video was perfect for me. Appreciate the experiment.

I’m a fitness person, have a good diet (usually), and have normal blood sugar levels when I visit my doctor for a checkup.

However, around 9:30 - 10:00am, I have a drop in energy every day. Usually, I have my first meal and am fine. But, right after that second small meal, I get hit with sluggishness. I have to eat because I’m hungry. Then, boom, get tired.

I’ve been trying to figure out why I get this energy drop for some time as it’s a constant battle.

But, sometimes i don’t get it at all and have perfect energy all day. I’ve been trying to figure it out. This provides some info about it.

It’s too bad those glucose monitors require a prescription. Most of us don’t have one. I’ll ask for one next doctor visit. And will experiment with foods, consistency in workouts, and timing to try and optimize this.

[pradanal.m.r.]

Could you please make a video of how exercise helps diabetes person? I have a hard time explaining it to my mom and my best friend, and your explanation actually very simple and user friendly for common people

[Divchyk]

Thank you, Dr. Lara! Great material! I wish, if you haven't done yet (will go through your videos later as just found you), you could do the same for different times of day. Glucose in our body works differently in the morning and in the evening.

[videogazer]

This is a great video. Don’t have many more like this?

[bleo]

Thanks for the video, very informative. It would be good if you could also have a video on fasting, and its impact on women's hormone.

[MrCvdx]

I exercised before eating breakfast for around a month and my weight decreased by 10 -15 lbs

Thanks for the great informations

[carolineyunker]

I think it's clear that exercise AFTER eating is optimal. It's more even. But any excercise is better than no exercise.