Exercise is one of the most powerful tools for managing diabetes, but not all exercise affects blood glucose the same way. Understanding how different types of training work, and how to exercise safely, can transform your diabetes management
Understanding Diabetes and Exercise
Diabetes affects how your body uses glucose for energy. In Type 1 diabetes, the pancreas produces little to no insulin. In Type 2 diabetes, your body becomes resistant to insulin or doesn’t produce enough. Both types benefit from exercise, but the approach differs
How Exercise Improves Insulin Sensitivity
The fundamental benefit of exercise is improved insulin sensitivity, meaning less insulin is required to transport glucose from the bloodstream into your muscles. Here’s what happens:
During Exercise:
- Muscle contractions increase GLUT-4 transporter molecules on cell surfaces, allowing more glucose to enter muscle cells in response to insulin
- Your muscles essentially become more receptive to the insulin your body produces
Long-Term Adaptations:
- Resistance training increases muscle mass, providing more sites for glucose storage and lowering overall blood sugars
- Aerobic training improves mitochondrial density, enhancing your body’s ability to use glucose for energy
- Exercise reduces inflammatory markers and increases inflammatory markers, which contributes to decreased insulin resistance
- Exercise reduces excess fat, especially around the organs, restoring healthy insulin response
Exercise Recommendations: What the Evidence Shows
Aerobic Exercise
Aim for at least 150 minutes per week of moderate-intensity aerobic activity, spread across at least 3 days with no more than 2 consecutive days without exercise.
Moderate intensity means you can talk but not sing comfortably during the activity:
- Brisk walking
- Swimming
- Cycling
- Dancing
- Team sports
Important note: While moderate aerobic exercise typically lowers blood glucose, high-intensity anaerobic exercise can temporarily raise glucose levels due to stress hormone release. This is normal but important to understand for safety.
Resistance Training: The Key to Insulin Sensitivity
Resistance training should be performed 2-3 days per week on non-consecutive days. This is where we focus on building muscle mass and strength—critical for improving insulin sensitivity.
Evidence-based prescription:
- For strength: 4-6 repetitions, 3-4 sets
- For muscle mass: 8-12 repetitions, 3-4 sets
- Total volume: 8-12 sets per week per muscle group
- Focus on large muscle groups: quadriceps, glutes, hamstrings, pectorals, and latissimus dorsi
These large muscles have the greatest capacity for glucose uptake and storage, making them priority targets for diabetes management.
Flexibility and Balance
Stretching and balance work help maintain mobility and prevent falls, especially if you have neuropathic complications.
Safety Considerations: Type 1 vs Type 2 Diabetes
For Type 1 Diabetes:
- Check for ketones if blood glucose is above 15 mmol/L—exercise should be avoided if ketones are present
- Understand “insulin on board” and how it affects exercise timing
- Be cautious with late-evening high-intensity exercise due to nocturnal hypoglycemia risk
- Timing of exercise relative to meals and insulin varies individually
For Type 2 Diabetes:
- Monitor blood glucose before and after exercise initially to understand your patterns
- If on insulin or certain medications, carry fast-acting carbohydrates during activity
- Focus on consistency over intensity when starting
Blood Glucose Safety Zones
Safe to exercise: 5.5–13 mmol/L
Treat low first: Below 4 mmol/L—consume fast-acting carbohydrates and recheck before exercising
Light exercise only: Above 15 mmol/L without ketones present
Avoid exercise: Above 15 mmol/L with ketones present
Complication-Specific Modifications
Retinopathy: Avoid high-load exercises with valsalva maneuver (straining while holding breath)
Peripheral neuropathy:
- Reduce high-impact activities
- Favor swimming and cycling over running
- Check feet daily for cuts or blisters
- Ensure proper footwear
Nephropathy: Avoid exercises that cause significant blood pressure spikes
Different Exercise Types, Different Glucose Responses
Understanding how your body responds to various exercise intensities helps you exercise safely:
- Moderate aerobic exercise: Usually lowers blood glucose during and after activity
- High-intensity and heavy resistance exercise: May temporarily raise blood glucose due to stress hormone release
- Combined aerobic and resistance training: Produces the most stable glucose levels over 24 hours
Making It Work for You
The most effective exercise program is one you’ll maintain consistently. Whether it’s swimming, group fitness classes, or morning walks, find activities you genuinely enjoy.
Starting out:
- Begin with 10-minute sessions if you’re new to regular exercise
- Gradually increase duration and frequency
- Monitor your blood glucose patterns to understand how your body responds
- Work with an Exercise Physiologist to optimize your program
Moving Forward
At Movement Rehabilitation, we create safe, personalized exercise programs based on your diabetes type, complications, medications, and lifestyle. Exercise isn’t just about burning calories, it’s about supporting long-term lifestyle changes to not only manage your diabetes, but also improve your overall health.
Tristan Surjadi is an Exercise Physiologist at Movement Rehabilitation specializing in chronic conditions including diabetes, cardiac conditions, and neuropathic conditions.
Book an Appointment
📍 Movement Rehabilitation – 645 Parramatta Road Leichhardt, NSW
📞 0449 703 967
✉️ info@movementrehabilitation.com.au
🌍 www.movementrehabilitation.com.au
For exercise physiology bookings, please book an initial consultation for a comprehensive assessment before beginning your personalized program.