Why Exercise Matters for Diabetes
When you have diabetes, your body doesn’t use insulin the way it should. That means sugar builds up in your blood instead of being used for energy. Exercise doesn’t just help you lose weight-it directly lowers blood sugar by making your muscles more sensitive to insulin. In fact, just 30 minutes of walking after a meal can cut post-meal spikes by nearly a third. Studies show that people who stick with regular physical activity lower their HbA1c by 0.5% to 0.7%. That’s the same drop you’d see with some medications-but without the side effects.
How Much Exercise Do You Really Need?
The guidelines are simple: aim for at least 150 minutes of moderate activity each week. That’s 30 minutes, five days a week. Or, if you prefer, 75 minutes of vigorous activity. The key is consistency. Your body’s improved insulin sensitivity fades after about 48 hours, so skipping two days in a row can undo your progress. You don’t need to run marathons. Brisk walking, cycling, swimming, or even dancing counts. The American Diabetes Association says if you can talk but not sing during your workout, you’re at the right intensity.
Strength Training Isn’t Optional
Muscle is your body’s biggest sugar-burning organ. The more muscle you have, the better your blood sugar control. Resistance training-using weights, resistance bands, or even your own body weight-should be done at least two to three times a week. Focus on all major muscle groups: legs, back, chest, arms, and core. Do two to four sets of 8 to 15 reps, at a weight that feels challenging by the last few reps. Research shows combining strength training with aerobic exercise cuts HbA1c more than either one alone. People who do both see nearly 0.6% greater improvement than those who only walk or only lift.
High-Intensity Workouts: Faster Results, But Watch Out
High-intensity interval training (HIIT) is efficient. You can get similar blood sugar benefits in 20 minutes as you would in 40 minutes of steady walking. A typical HIIT session might include 30 seconds of fast cycling or stair climbing, followed by 90 seconds of slow recovery, repeated 6 to 8 times. Studies show HIIT can reduce HbA1c by up to 0.8% more than moderate exercise per minute spent. But it’s not for everyone. If you have heart problems, nerve damage in your feet, or advanced eye disease from diabetes, skip HIIT. Also, people with type 1 diabetes often see a temporary spike in blood sugar after intense sessions. That’s not dangerous, but it means you may need a small insulin adjustment afterward.
Break Up Your Sitting Time
Sitting for long periods-even if you exercise for an hour a day-is harmful. One study found that standing up and walking for just three minutes every 30 minutes during an 8-hour day cut post-meal blood sugar by 24% and insulin levels by 20%. You don’t need a gym. Set a timer. When it goes off, walk to the kitchen, do a few squats, or stretch your arms overhead. These tiny movements add up. For people with type 2 diabetes, especially those who work desk jobs, this simple habit can be more effective than a long workout once a week.
When to Check Your Blood Sugar
If you take insulin or medications that can cause low blood sugar, check your levels before, during (if exercising over an hour), and after exercise. Test 15 to 30 minutes before you start. If your blood sugar is below 100 mg/dL, eat 15 to 30 grams of fast-acting carbs-like fruit, juice, or glucose tablets. If it’s above 250 mg/dL and you have ketones in your urine, don’t exercise. That’s a warning sign your body is under stress. If you use a continuous glucose monitor (CGM), you’ll see real-time trends. Many people find CGMs reduce the guesswork and make exercise safer.
Medication Adjustments: What to Do
If you use insulin, you’ll likely need to adjust your dose around exercise. For 60 minutes of light activity, reduce your mealtime insulin by 10-20%. For moderate activity, cut it by 20-40%. For high-intensity workouts, reduce it by 30-60%. People on insulin pumps can lower their basal rate by 50% one hour before exercise and keep it reduced during and after. Always talk to your doctor before making changes. If you’re exercising for more than an hour, carry 15 grams of carbs every 30 minutes. Keep them with you-even if you don’t think you’ll need them.
What to Avoid
Not all exercise is safe for everyone with diabetes. Avoid high-impact activities like jumping or running if you have nerve damage in your feet. That can lead to ulcers or infections. Pregnant women with gestational diabetes should keep heart rates under 140 bpm and avoid lying flat on their backs. People with severe retinopathy should skip heavy lifting or activities that involve straining or head-down positions, as these can increase pressure in the eyes. And never exercise on an empty stomach if you’re on insulin-it increases your risk of a low-blood-sugar episode.
Real-Life Success Stories
One woman in York, 58, with type 2 diabetes, started walking 3 miles a day, five days a week. She didn’t change her diet. Within three months, her HbA1c dropped from 8.1% to 6.9%. Another man, 62, added two days of resistance training using bands at home. After six months, he cut his insulin dose in half. These aren’t outliers. They’re people who followed the science: consistent movement, smart timing, and listening to their bodies.
Getting Started Without Overwhelm
You don’t need a gym membership or fancy gear. Start with walking. Park farther away. Take the stairs. Do chair squats while watching TV. Build up slowly. Most people who quit exercise programs do so within six months-not because they can’t do it, but because they feel alone or overwhelmed. Find a buddy. Join a local walking group. Use a free app to track your steps. The goal isn’t perfection. It’s showing up. Even 10 minutes a day is better than nothing.
The Bigger Picture
Only about 40% of adults with diabetes meet the recommended activity levels. The reasons? Time, cost, fatigue, or fear of low blood sugar. But the cost of inaction is higher. Regular exercise reduces your risk of heart disease by 31%, cuts the chance of nerve damage, and improves your energy and mood. It’s not a cure-but it’s the most powerful tool you have outside of medication. And unlike pills, it doesn’t cost a penny.
What’s Next?
Technology is making it easier. New apps now sync with CGMs to suggest real-time adjustments before, during, and after workouts. In the next few years, AI tools will predict how your body will respond to different types of exercise based on your glucose patterns. But right now, the best tool you have is your own two feet. Start small. Stay consistent. Your blood sugar will thank you.
