Can Calf Raises Lower Blood Glucose?
Yes, calf raises and other resistance exercises can help lower blood glucose levels, but they should be part of a comprehensive exercise program that includes at least 150 minutes of moderate-intensity aerobic activity per week plus resistance training on 2-3 nonconsecutive days per week. 1, 2
Evidence for Resistance Exercise and Glucose Control
The American Diabetes Association guidelines establish that resistance training of any intensity improves glycemic control and strength in people with diabetes 1. While heavier resistance training with free weights and weight machines may provide superior improvements in glycemic control, resistance training at any intensity level—including bodyweight exercises like calf raises—is beneficial 1.
Exercise training improves insulin sensitivity, which is the fundamental mechanism by which physical activity lowers blood glucose 1, 3. Regular exercise has been proven to:
- Reduce glycosylated hemoglobin (A1C) levels 3
- Improve insulin sensitivity and glucose control 1, 3
- Favorably affect cardiovascular risk factors including lipid profiles and blood pressure 3
- Reduce body fat percentage while enhancing lean muscle mass 3
Practical Implementation
The American College of Sports Medicine recommends a specific exercise prescription for diabetes management 2:
- Aerobic component: At least 150 minutes of moderate-intensity activity per week 1, 2
- Resistance component: At least twice weekly on nonconsecutive days 1, 2
Calf raises alone would not constitute adequate resistance training. They should be incorporated as part of a broader resistance training program targeting multiple muscle groups 1.
Important Safety Considerations
Hypoglycemia Risk
For patients taking insulin or insulin secretagogues, physical activity can cause hypoglycemia if medication doses or carbohydrate intake are not adjusted 1. Specific precautions include:
- Check blood glucose before and after exercise 1
- Consider ingesting added carbohydrate if pre-exercise glucose is <90 mg/dL (5.0 mmol/L) 1
- Be aware that hypoglycemia can occur hours after exercise due to increased insulin sensitivity 1
- Patients not on insulin or insulin secretagogues have minimal hypoglycemia risk and typically require no preventive measures 1
Intense Exercise Effects
A critical caveat: intense activities may actually raise blood glucose levels instead of lowering them, especially if pre-exercise glucose levels are already elevated 1. This paradoxical response occurs due to counterregulatory hormone release during high-intensity exercise 1.
Contraindications and Precautions
Certain complications require exercise modification 1:
- Proliferative diabetic retinopathy or severe nonproliferative retinopathy: Vigorous-intensity aerobic or resistance exercise may trigger vitreous hemorrhage or retinal detachment; ophthalmology consultation is appropriate before intense exercise 1
- Peripheral neuropathy: Patients should wear proper footwear, examine feet daily, and avoid weight-bearing activities if foot injuries or open sores are present 1
- Autonomic neuropathy: Requires cardiac investigation before beginning activity more intense than usual, due to increased risk of exercise-induced injury and silent myocardial ischemia 1
Clinical Bottom Line
While calf raises can contribute to lowering blood glucose as part of a resistance training program, they should not be viewed as a standalone intervention. The glucose-lowering benefits come from the cumulative effect of regular, structured exercise that includes both aerobic and resistance components 1, 2, 3. Patients should work toward meeting the full recommended exercise targets with stepwise goal-setting and appropriate medical monitoring to ensure safety and evaluate effects on glucose management 1.