Exercise and Diabetes – How to Train Safely and Effectively

What happens in your body when you exercise?

When your muscles work, they use blood sugar as energy — and this happens partly without the need for insulin. This is why even a short walk after dinner can noticeably lower blood sugar.

Regular exercise also makes your cells more sensitive to insulin (reduces insulin resistance), which is the core problem in type 2 diabetes.

Types of exercise – effects and recommendations

Activity type	Effect on blood sugar	Recommendation
Brisk walking	Lowers gradually during and after	30 min daily, ideally after meals
Strength training	Lowers, increases muscle mass long-term	2–3 times per week
Cycling / swimming	Lowers effectively	20–45 min, 3–5 days/week
Interval training (HIIT)	May raise briefly, lowers over time	With caution, monitor blood sugar
Yoga / stretching	Moderate effect, reduces stress	Good supplement
Everyday activity	Cumulative effect throughout the day	Take stairs, walk to the shop

Safe exercise – what you need to know

Check blood sugar before exercise

Always measure blood sugar before starting, especially if you use insulin or certain tablets.

● Below 5 mmol/L: Eat 15–20g of carbohydrates and wait 15 min
● 5–15 mmol/L: Safe to exercise
● Above 15 mmol/L: Postpone exercise, check ketones if type 1

Always carry with you:

Fast carbohydrates (glucose tablets, juice) during exercise. Hypoglycaemia can occur during or up to 12 hours after intense exercise.

After exercise

Blood sugar can continue to fall for 12–24 hours after intense exercise. Check blood sugar after exercise and consider a small snack if it is below 7 mmol/L.

Getting started – step by step

Week 1–2: Start with 10–15 minutes of brisk walking after dinner every day. Low threshold and very effective.
Week 3–4: Increase to 25–30 minutes. Add an extra walk after lunch.
Month 2: Add 2 simple strength sessions per week — home exercises like squats, wall push-ups and resistance bands work well.
Long-term goal: 150 minutes of moderate activity per week = clinically documented HbA1c reduction.

Everyday activity counts!

You don't need gym clothes and a gym membership to benefit. Studies show that breaking up sitting every 30 minutes with just 3 minutes of light movement reduces blood sugar spikes by up to 30%.

🚶 Take the stairs instead of the lift
🛒 Walk to the shop instead of driving
📺 Do simple exercises while watching TV
🅿️ Park further away and walk the rest

When should you consult a doctor first?

Consult your doctor or diabetes care team before starting a new exercise programme if you:

● Have had a heart attack or heart disease
● Have kidney damage or eye damage (retinopathy)
● Have frequent low blood sugar episodes
● Have been physically inactive for a long time