How Exercise Boosts Your Body’s Ability to Manage Blood Sugar: The Science Behind Insulin Sensitivity

Graphic showing the link between exercise and blood sugar management

Okay, so that last blog was only an intro to the science. Now I will explain how working out, as the title says, boosts your body's blood sugar management, and what that can do for your performance. Obviously, that last part is actually great for everyone, diabetics and non-diabetics! This is going to be a "quick" list discussing the overall benefits of exercise and blood sugar management.

Exercising and glucose uptake!
- How Exercise Enhances Glucose Absorption
  In simple terms, exercise boosts how your cells absorb glucose (sugar), even without insulin! When you work out, your muscles contract and become better at pulling glucose from your bloodstream. This process lowers your blood sugar levels because your muscles need that glucose to function, effectively giving them the "fuel" they need. That’s why exercise is a top recommendation for diabetics—it’s a game-changer for managing blood sugar levels.
- The Benefits of Regular Exercise on Insulin Sensitivity
  Your body is like a highly efficient machine. As you keep exercising, your muscles adapt and become even better at handling glucose. They grow more insulin-sensitive, meaning they need less insulin to get the same amount of glucose into your cells. This improved sensitivity helps regulate your blood sugar more effectively and can enhance your muscle growth and fueling. Just a note: while this theory sounds promising, it’s always good to stay updated with the latest research.
What Is Insulin Sensitivity?
- Insulin Sensitivity
  When we talk about insulin sensitivity, we're referring to how efficiently your muscles use insulin to absorb glucose (sugar). Higher insulin sensitivity means your body needs less insulin to get the same glucose uptake. And after you exercise, your insulin sensitivity improves, making it easier for your muscles to absorb glucose with less insulin.
- Understanding Insulin Responsiveness
  Insulin responsiveness measures how much glucose your muscles take up when given a full dose of insulin. Improved responsiveness means that when insulin is at its peak effectiveness, your muscles can absorb more glucose. In simpler terms, higher responsiveness means your muscles can handle more glucose when insulin levels are high.
How Exercise Supercharges Glucose Uptake
- Calcium Release Boosts Glucose Absorption
  When you exercise, your muscles start releasing calcium from their internal stores. This calcium then triggers Ca2+/calmodulin-dependent protein kinase (CaMK) II. Think of CaMK II as a key player in the process—it helps muscles grab glucose from your blood, even without insulin. So, when you're working out, you're essentially fueling your muscles with the sugar they need to keep going. This is why exercise is so incredibly beneficial for diabetics—it helps regulate blood sugar levels more efficiently.
AMPK Activation Drives Glucose Transport
- AMPK Activation
  Exercise sparks AMP-activated protein kinase (AMPK), a crucial player in how your body handles glucose. Here’s the lowdown: during exercise, your cells use up ATP (adenosine triphosphate), which is their primary source of energy. As ATP levels drop and AMP (adenosine monophosphate) levels rise, AMPK gets activated. Think of AMPK as a signal booster that ramps up glucose transport in your muscles. It helps your muscles become more efficient at pulling in glucose, even without relying heavily on insulin. This boost in glucose uptake aids in better blood sugar control and overall energy management, making every workout session a win for your body’s glucose handling.
Long-Term Benefits of Exercise
- The Actual Benefits of Exercising
  Even though the immediate spike in glucose absorption from exercise might wear off within a few hours, the benefits don’t end there. Your muscles keep their enhanced glucose-absorbing power for several days after you work out. This extended boost happens especially when you keep your carbohydrate intake in check, which means your body doesn’t quickly replenish its glycogen stores. So, this lasting effect is like a bonus for better management of your blood sugar over time.
How Exercise Boosts GLUT4 Transporters for Better Glucose Uptake
- The Importance of GLUT4
  GLUT4 (glucose transporter type 4) proteins are the MVPs when it comes to moving glucose into your muscle cells. When you exercise, your body ramps up the number of GLUT4 transporters on the surface of your muscles. This increase means your muscles can pull in glucose more effectively. Even after your workout is over, those extra GLUT4 transporters can stick around for days, particularly if you’re keeping your carbs in check. This lingering boost makes your muscles stay more responsive to insulin and other glucose signals, giving you an extended period of improved glucose management.
Broad Sensitivity: More Than Just Insulin
- The Many Benefits of Moving
  Exercise doesn’t just boost your muscles’ insulin sensitivity; it also enhances their response to other signals like low oxygen levels (hypoxia). This means your muscles get better at picking up various cues, not just insulin, which helps with overall glucose management and muscle function. So, after a workout, your muscles become more adaptable and effective at managing glucose from multiple sources.
The Role of Serum Factors (from what we know, or I was able to find)
- How Exercise and Insulin Mingle
  For exercise to truly ramp up insulin sensitivity, a specific serum protein in your blood is needed. This protein isn’t present in artificial lab settings, which is why studies in these environments often miss the mark. The exact role of this serum factor is still a mystery, but it’s essential for the increased insulin sensitivity seen after exercise.
Mimicking Exercise: What Works?
- AMPK Activators
  Some compounds, like AICAR, can activate a protein called AMP-activated protein kinase (AMPK) in a way that’s similar to the effects of exercise. Think of AMPK as a switch that helps your body use glucose more efficiently. When you exercise, your muscles naturally activate AMPK to help absorb glucose. AICAR and similar compounds can turn on this switch even without working out, potentially offering some of the same benefits for managing blood sugar.
- Lithium
  A substance sometimes used in treatments for mood disorders, can also improve how your muscles take up glucose, much like exercise does. The interesting part is that lithium doesn’t rely on certain blood proteins that are needed for exercise-induced effects. This makes it a distinct option for enhancing glucose sensitivity, though it’s not a replacement for physical activity.

With Ongoing Research: The Quest Continues

Even with great strides, many aspects of how exercise enhances insulin sensitivity are still being explored. Researchers know exercise affects various pathways, but the exact molecular processes are still under the microscope. This ongoing research highlights the complexity and excitement of understanding exercise’s role in glucose transport and insulin sensitivity.

Now, hopefully, you read all of that, but it's a LOT of information. If you're part of the TLDR crowd: exercise is amazing to help you not only increase your hormonal sensitivity but with insulin specifically, your ability to build and maintain muscle. This blog also just happened to have a bunch of science to prove it. The sources where I was able to gather much of the information to put this stuff together will be below, but there are so many hormonal benefits to exercise that NOT exercising.. kind of becomes willingly embracing a crappy life. Overall, it takes more effort than to simply sit on a couch, but less effort than you think to start feeling amazing, and for me at least, to not feel guilty about eating pizza once in a while! Haha.. Sources: 1. Exercise and Glucose Absorption

Source: "Physical Activity and Insulin Sensitivity"

Journal: Current Opinion in Endocrinology, Diabetes and Obesity

Link: https://journals.lww.com/co-endocrinology/Abstract/2020/12000/Physical_activity_and_insulin_sensitivity.7.aspx

2. Calcium Release and Glucose Uptake

Source: "Calcium and Glucose Metabolism in Muscle Cells"

Journal: Journal of Physiology

Link: https://physoc.onlinelibrary.wiley.com/doi/10.1113/jphysiol.2016.315100

3. AMPK Activation and Glucose Transport

Source: "AMP-Activated Protein Kinase: A Key Regulator of Glucose Metabolism"

Journal: American Journal of Physiology-Endocrinology and Metabolism

Link: https://journals.physiology.org/doi/full/10.1152/ajpendo.00271.2007

4. GLUT4 Transporters