Exercise
How much is enough, what counts as moderate, and why a 10-minute walk after dinner outperforms an hour at the gym done once a fortnight.
The short version
- Aim for 150–300 minutes a week of moderate aerobic activity, spread over most days — New Zealand’s national physical activity guideline.
- A single session improves insulin sensitivity for 24–72 hours. It works like a medicine that wears off, so it needs a regular dose: most days, not once a week.
- 10–15 minutes of walking after your main meals blunts the glucose spike more efficiently, minute for minute, than the same walk at another time of day. If you cannot get out for a walk, try not to sit down for the first 30 minutes after eating.
- Add two short resistance sessions a week. Muscle is where glucose goes, so it matters as much as cardio.
- Triglycerides and blood pressure respond first; LDL-C responds modestly; fitness — the strongest single predictor of long-term outcomes — responds most of all.
Why exercise is the closest thing to a wonder drug
Exercise is one of the most powerful medicines that has been given to us. It improves insulin sensitivity and offers numerous benefits for cognition, mood and metabolic health. Muscle contraction opens an insulin-independent door for glucose: working muscle pulls sugar out of the blood without needing insulin to knock on. That is why a single walk can lower blood glucose within minutes, and why sensitivity stays improved for a day or two afterwards.
The lipid effects follow a similar pattern. Regular aerobic activity raises HDL-C slightly, lowers triglycerides meaningfully — especially when combined with the 7pm rule, makes LDL particles somewhat larger and less atherogenic, and improves how the lining of your arteries dilates. Blood pressure usually falls by several points. Cardiorespiratory fitness — measured as VO₂ max — is one of the strongest predictors of long-term survival in any population studied, stronger than cholesterol, smoking or diabetes on their own.
What counts as moderate?
You can talk in sentences but not sing. On an effort scale of 0–10 that is around 4–6: breathing deeper, warm, able to keep going but not comfortable doing nothing.
| If you are starting from | Do this first (weeks 1–2) | Build to (weeks 5–8) |
|---|---|---|
| Sedentary | 10-minute walk after lunch and dinner, 5 days a week | 20–25 minutes most days, plus one longer weekend walk |
| Occasionally active | 20–30 brisk walks a week in 10-minute blocks | 150 minutes/week: e.g. 30 min × 5 days, one on an incline |
| Already active | Add one interval session: 8 × 1 min hard / 2 min easy | 200–300 min/week with 2 quality sessions + 2 resistance sessions |
Anything that lifts your heart rate counts and can be stacked: brisk walking, rucking (a weighted pack), cycling, the stair machine, swimming, rowing, garden work at a pace, doubles tennis. For joint pain or neuropathy, cycling, pool work and the elliptical usually win.
The post-meal walk
Contracting muscle soaks up the glucose arriving from the meal straight off the bloodstream, so less insulin is needed and the peak is smaller and shorter. On a continuous glucose monitor the effect is obvious within a week: the mountain becomes a hill. It also stacks neatly with the 7pm rule — an evening walk after dinner doubles as the thing you do instead of grazing.
Cannot get out for a walk? Try not to sit for the first 30 minutes after a meal. Standing and light movement around the house still helps your muscles take up glucose: washing up, tidying the kitchen, hanging out the washing, or walking around the house during a phone call. If you have to sit, get up and move for a few minutes every half hour.
Add resistance twice a week
Two sessions, 20–30 minutes each, on non-consecutive days: legs, back, chest, in whatever order. Machines, bands, dumbbells, a bodyweight circuit or a class all count.
- Start with 1 set of 8–12 repetitions per exercise and add a second set after two weeks — an RPE of about 6–7 out of 10, meaning you could do 3 more reps.
- Sit-to-stand from a chair, wall press-ups, rows with a band, step-ups and carries cover nearly everything needed at the start.
- Progress by adding a repetition before you add weight. Soreness for a day is fine; sharp pain in a joint is not.
Safety and common questions
- Hypoglycaemia: insulin or sulfonylurea doses often need reducing on exercise days — carry glucose tablets, check before and after activity at first, and expect delayed lows up to 12 hours later after a hard session.
- Blood glucose very high (over ~15 mmol/L with type 1, or with ketones): do not exercise hard until it settles; a gentle walk is fine if you feel well and are hydrated.
- Feet: with neuropathy or peripheral arterial disease wear well-fitting shoes, check feet after activity, and prefer low-impact options.
Making it stick
- Pick a time that already exists in your day — after meals is ideal, because the meal is the cue.
- Lower the bar to something you will do badly. Ten minutes done beats forty planned. Consistency compounds, intensity does not rescue a skipped week.
- Tie it to company if that works for you: a walking group, a fixed call with a friend, badminton, a dog that needs the round twice.
- Track one number only — minutes of moderate activity per week. That is the target to grow over two months.
In this series: the 7pm rule, then seven steps to better sleep.
Written by Dr Huan Chan. Last reviewed: September 2026. General information only — it does not replace advice from your own diabetes or heart team.