That fact is the heart of this chapter. In Chapter 1 you met the GLUT4 doorway and saw that, in insulin resistance, the insulin signal that opens it works less well. Movement offers a second key to the same door. It is not a cure, and it does not replace food choices or medicines. But it is one of the few tools that costs little, needs no prescription, works in any country, and helps in prediabetes and in type 2 diabetes, and has a place in type 1 diabetes too, with some extra safety steps.

It also comes with real safety questions, especially for anyone who uses insulin or certain tablets, so this chapter does not stop at "move more". We begin with how muscles use glucose, and why a walk lowers your reading. We then look at which kinds of activity help and how much the evidence supports, including practical options that need no gym. Finally we cover safety: lows, highs, hearts, eyes, nerves, feet, heat, pregnancy, and age.

9.1 How Muscles Use Glucose

The biggest customer

After a meal, glucose leaves the blood mainly by entering cells, and skeletal muscle, the muscle you use to walk, lift, and stand, is the largest tissue able to take it. In Chapter 1 you saw the standard route: insulin arrives, a signal runs inside the cell, and GLUT4 transporters travel to the cell surface and open like doors so that glucose can enter. In insulin resistance, that signal is weaker, and the doors open less readily.

A second route that does not need insulin

Muscle has another way to open the same doors. When muscle fibres contract, they trigger their own signals inside the cell, and these bring GLUT4 to the surface and increase glucose uptake without insulin being involved.[@richter2013] A review of the molecular biology summarises it this way: the signalling that drives glucose uptake during exercise is distinct from the signalling activated by insulin, and exercise-stimulated uptake is preserved in insulin-resistant muscle.[@sylow2017] In plain terms, even when the insulin doorbell works poorly, the contraction route is still available.

{{fig:F9-A}}

This is why a short walk can lower glucose so quickly. The plate (Chapter 6) limits how much glucose arrives; movement helps clear what does.

What happens after you stop

The effect does not switch off the moment you sit down. The ADA's position statement on physical activity describes an insulin-independent effect that lasts for a couple of hours after activity, and improved insulin action that may last about 24 hours after shorter sessions and up to about 48 hours after prolonged ones.[@colberg2016] A later consensus statement from the American College of Sports Medicine says that improvements in whole-body insulin sensitivity after activity can last anywhere from 2 to 72 hours, depending on how long and how hard the activity was.[@kanaley2022]

Science Corner: How long does one session "last"? You may see claims that a workout lowers glucose "for 48 hours". The sources above show why that number needs care. The insulin-independent effect fades within hours. The longer-lasting part is greater sensitivity to insulin, and how long it lasts depends on how long and intense the activity was and on the person; the ranges reported are wide (roughly 2 hours to 3 days) and describe averages under study conditions, not a guarantee for your body. The practical message is the same either way: the benefit is real but temporary, so what matters is repeating activity regularly, and leaving no more than a couple of days between sessions.[@colberg2016]

9.2 What Kind, and How Much

The official numbers

Two sets of numbers are worth knowing. The World Health Organization's 2020 guidelines say that adults, including adults living with chronic conditions such as type 2 diabetes, should do at least 150 to 300 minutes of moderate-intensity aerobic activity a week, or at least 75 to 150 minutes of vigorous-intensity activity, plus muscle-strengthening activities on two or more days a week. They also say that adults should limit sedentary time, and that replacing sitting with activity of any intensity, including light activity, gives health benefits.[@who2020pa] "Moderate" means you breathe harder and your heart rate rises, but you can still talk. "Vigorous" means you can say only a few words at a time.

The ADA position statement is more specific about how to spread it. It advises most adults with diabetes to do 150 minutes or more of moderate-to-vigorous activity a week, over at least three days, with no more than two days in a row without activity, and two to three sessions a week of resistance exercise on non-consecutive days. Shorter, vigorous sessions (a minimum of 75 minutes a week) may be enough for younger or fitter people.[@colberg2016] The ADA updates its full Standards of Care every year, and the current edition contains a section on physical activity that you can ask your care team about.[@ada2026pa]

The WHO adds something easy to miss: doing some activity is better than none, and adults should start with small amounts and build up gradually.[@who2020pa] If you are not active today, ten minutes on most days is a real start. For scale, 30 minutes on five days is 150 minutes, and so is a 10-minute walk after each of three meals on five days.

Aerobic activity

Aerobic (or "cardio") activity is anything rhythmic that raises your breathing and heart rate for a sustained period: brisk walking, cycling, swimming, dancing, hiking, and jogging. A consensus statement from the American College of Sports Medicine reports that regular aerobic training improves glycemic control in adults with type 2 diabetes, with fewer high-glucose excursions during the day and reductions in HbA1c of about 0.5 to 0.7 percentage points.[@kanaley2022] For context, HbA1c is the three-month glucose average you met in Chapter 4.

Strength (resistance) training

Resistance training means working muscles against a load: weights, machines, elastic bands, your own body weight (squats, wall press-ups, standing up from a chair), or heavy carrying and digging. The ACSM statement reports that in adults with type 2 diabetes it typically produces improvements of 10 to 15 percent in several outcomes, including insulin sensitivity.[@kanaley2022] More muscle, and muscle that contracts regularly, gives glucose more places to go.

Combining, and the evidence on HbA1c

Several large reviews have pooled trials of exercise in type 2 diabetes. A 2011 meta-analysis of 47 randomised trials (8,538 patients, each trial at least 12 weeks) found that structured exercise training was associated with an HbA1c 0.67 percentage points lower. Physical activity advice alone, without structured training, produced no significant change. Trials with more than 150 minutes of exercise a week showed a greater fall (0.89 points) than those with 150 minutes or less (0.36 points).[@umpierre2011]

The largest recent review, published in 2026, pooled 100 randomised trials with 7,195 participants and found the following.[@michielsen2026]

Pooled HbA1c reductions in adults with type 2 diabetes, from a 2026 meta-analysis of 100 randomised trials (7,195 participants), as reported in its abstract.[@michielsen2026] Intervals are 95% confidence intervals; trials differed in duration, supervision, and participants.

The same review found the largest benefit with 150 to 210 minutes a week and about three sessions a week, and larger effects in supervised programmes than in unsupervised ones. It also flagged limitations: signs of publication bias for aerobic and interval training, wide differences between studies, and modest study quality.[@michielsen2026]

An earlier trial gives a picture of how the types compare. In the HART-D trial, 262 sedentary adults with type 2 diabetes trained for nine months. Compared with no exercise, HbA1c fell by 0.34 percentage points with combined aerobic and resistance training, a statistically significant change. The falls with aerobic training alone (0.24) and resistance training alone (0.16) were smaller and not statistically significant in that trial.[@church2010]

The message is consistent: the evidence supports both types, and the combination looks at least as good as either alone.

High-intensity interval training

HIIT alternates short hard efforts with easier recovery. A meta-analysis of 20 randomised trials (738 adults, mostly with overweight or obesity, not only diabetes) found that low-volume HIIT lowered HbA1c by 0.70 percentage points compared with no exercise, and did not differ significantly from moderate continuous exercise. It also noted high variation between studies and that only 30 percent were rated high quality.[@lu2025] HIIT can be time-efficient, but it is not necessary, and harder efforts call for more caution (section 9.3). The ACSM statement notes that it improves fitness and lowers HbA1c and BMI in adults with type 2 diabetes, while the ADA statement says shorter vigorous or interval sessions may suit younger and fitter people.[@kanaley2022][@colberg2016]

Science Corner: How much weight can these numbers bear? These reviews pool many small trials with different designs. Exercise cannot be hidden from participants, so blinding is not possible, people who volunteer for exercise trials may be more motivated than average, and some studies include medicine changes during the trial that blur the effect of exercise alone. The size of the effect also depends on where you start: people with higher HbA1c usually have more room to fall. So treat "0.5 to 0.7 points" as a typical average and not a promise, and remember that exercise works alongside the food and medicine plan your team recommends, not instead of it. The consistent direction of the findings across different reviews, more than any single number, is what makes the advice reliable.

Flexibility, balance, and yoga

Stretching and balance work do not lower glucose much, but they keep you moving and prevent falls. The ACSM statement notes that exercises that enhance joint flexibility are highly beneficial and that balance exercises may reduce the risk of falls.[@kanaley2022] The ADA statement recommends balance training two to three times a week for older adults with diabetes.[@colberg2016]

Yoga, which combines postures, breathing, and relaxation, has been studied too. A 2026 meta-analysis of 28 randomised trials with 2,241 adults with type 2 diabetes found an average HbA1c reduction of 0.64 percentage points (95% credible interval 0.41 to 0.87 points), but rated the certainty of the evidence as low and noted that little of the evidence came from outside India. The authors described yoga as a feasible addition to standard care, not a substitute for it.[@li2026] If yoga appeals to you, it is a reasonable addition. It is not proven to replace aerobic and strength work.

Sitting less, and moving after meals

Sitting for hours at a stretch has its own effect on glucose. The ADA statement suggests interrupting prolonged sitting with bouts of light activity every 30 minutes, at least in adults with type 2 diabetes.[@colberg2016] In a laboratory trial of 24 inactive adults with overweight or obesity and type 2 diabetes, 3-minute bouts of either light walking or simple resistance movements (half-squats, calf raises, and similar) every 30 minutes across a 7-hour period lowered glucose, measured over 22 hours, compared with sitting throughout.[@dempsey2017] A pooled analysis of seven studies in adults without diagnosed diabetes also found that light walking breaks lowered glucose and insulin after meals compared with continuous sitting.[@buffey2022]

Timing matters too. In a crossover trial in New Zealand, 41 people with type 2 diabetes tried two 2-week routines in random order: 30 minutes of walking at any time of day, and 10 minutes of walking immediately after each of three meals. Glucose after meals was about 12 percent lower on average with the post-meal walks, and about 22 percent lower over the three hours after the evening meal.[@reynolds2016] The ACSM statement agrees that activity after a meal lowers glucose whatever the type, with sessions of 45 minutes or longer giving the most consistent benefit.[@kanaley2022] Put simply: a short walk after your biggest meal is a good habit, and longer is not always necessary to see a change.

Low-cost, do-it-anywhere ideas

You do not need a gym, a pool, or special clothing. The guidelines describe amounts and intensity, not particular activities, and the WHO notes that adults who cannot meet the targets should be active according to their abilities.[@who2020pa] Anything that makes your breathing and heart rate rise and uses large muscles can count toward the aerobic total. Some ideas from around the world:

• Brisk walking, including to market, work, or school, and taking stairs instead of lifts.
• Cycling to where you need to go.
• Dancing at home, at a class, or at a celebration.
• Gardening, farm work, carrying water or shopping, and heavy housework, when done at a pace that raises your breathing.
• Body-weight strength moves: squats to a chair, wall press-ups, step-ups, calf raises.
• Elastic resistance bands, water bottles or bags of rice as weights, or a simple set of dumbbells.
• Yoga, tai chi, or stretching routines, for flexibility and balance.

The best activity is the one you will still do next month: choose something you enjoy, in a place that feels safe.

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9.3 Staying Safe

For most people, activity is safe and beneficial. But diabetes brings extra points to think about, and some depend on which medicines you take. Everything in this section is general; your care team knows your medicines, your complications, and your history.

Hypoglycaemia (low glucose)

Muscles pull glucose out of the blood, so activity can push glucose too low in people who take insulin or a sulfonylurea (a class of tablets that increases insulin release; see Chapter 11). Metformin on its own is generally considered safe for exercise without adjustment, because it does not usually cause lows.[@colberg2016] The ACSM statement advises people with type 2 diabetes who use insulin or insulin secretagogues to add carbohydrate, or to reduce insulin where possible, to prevent lows.[@kanaley2022]

A low can also happen later than you expect. The ADA statement notes that hypoglycaemia after exercise typically occurs within 6 to 15 hours, although the risk can extend to 48 hours.[@colberg2016] This is why a low can appear in the evening, or overnight, after a busy day.

If you use insulin or medicines that can cause lows, talk to your care team before you begin or increase activity. Ask what they want you to do with food and with medicines on active days. Do not adjust your medicines or make your own rules yourself. Chapter 13 covers how to recognise and treat a low and what counts as an emergency; keep fast-acting carbohydrate with you when you are active, and tell someone you are with.

Check your glucose, and know your pattern

The ADA statement notes that people whose treatment risks lows need frequent glucose checks to manage food and medicine around activity.[@colberg2016] A meter or a continuous glucose monitor (Chapter 12) shows you how your body responds: before, during (for longer sessions), and after, including later in the day. Write the results down for a few weeks and bring them to your care team; patterns such as "always lower after the evening walk" are what help them most.

Highs and ketones

Very high glucose is also a reason to pause. In type 1 diabetes, when glucose is high and the body has too little insulin, it can produce ketones (acids made when fat is used for fuel), and exercise can make this worse. The ADA statement advises testing for ketones when glucose is 250 mg/dL (13.9 mmol/L) or higher, and postponing exercise if blood ketones are 1.5 mmol/L or higher or moderate to large amounts are present.[@colberg2016] If you feel unwell, are vomiting, or have breathing difficulty with high glucose or ketones, do not exercise; this may be diabetic ketoacidosis, an emergency that is covered in Chapter 13. If you have type 1 diabetes, ask your team for your personal thresholds and what to do.

Heart, eyes, nerves, and feet

This table summarises cautions from the ADA position statement and the ACSM consensus statement; it is not a substitute for a check-up. Details of complications are in Chapters 14 and 15.

Who needs a medical check before starting? Both statements say that people without symptoms who are receiving diabetes care and wish to begin low- or moderate-intensity activity, such as brisk walking or the demands of everyday life, generally do not need a medical evaluation first. Those who plan vigorous activity, or who have symptoms or risk factors for heart disease, may benefit from a check-up and possibly an exercise stress test.[@colberg2016][@kanaley2022] If you are unsure which group you are in, ask.

Heat, water, and illness

Heat and dehydration raise the risk of feeling unwell and can make glucose harder to predict. The ADA statement advises older adults with diabetes, and anyone with autonomic neuropathy, heart or lung disease, to avoid exercising outdoors on very hot or humid days.[@colberg2016] Drink water before, during, and after activity, and choose the cooler parts of the day. As a general rule (our own suggestion, not from the sources above), pause hard exercise when you are ill with a fever, vomiting, or diarrhoea, and check with your care team, especially if you use insulin or tablets such as SGLT2 inhibitors, since illness can affect your glucose and hydration (Chapter 13).

Pregnancy, older age, and limited mobility

In pregnancy, activity is still encouraged. The WHO recommends at least 150 minutes of moderate-intensity activity a week for pregnant and postpartum women without a medical reason to avoid it,[@who2020pa] and the ADA statement mentions 20 to 30 minutes of moderate exercise on most days for women with gestational diabetes, and cautions that pregnant women using insulin should be aware that exercise makes insulin work better and can cause lows.[@colberg2016] Plan with your obstetric and diabetes team.

For older adults, the WHO advises varied multicomponent activity that emphasises balance and strength on three or more days a week, to improve function and prevent falls.[@who2020pa] If you have arthritis, a joint replacement, heart failure, or another condition that limits movement, or if you use a wheelchair, chair-based exercise, water exercise, and shorter, more frequent bouts all count. The WHO recommends adults living with disability ask a health professional or a specialist in physical activity and disability for the type and amount of activity that suits them.[@who2020pa] Not being able to reach 150 minutes is not a failure; activity according to your abilities is still beneficial.

When to seek urgent help

Stop and seek urgent medical help for chest pain or pressure, severe breathlessness, fainting, or signs of a serious low that does not improve (confusion, inability to swallow, seizure). If someone is unconscious, call emergency services and do not put food or drink in their mouth (Chapter 13).

Key Takeaways

• Contracting muscles take up glucose by a route that does not depend on insulin, and this route stays available even in insulin resistance; that is why even a short walk lowers glucose.
• The benefit lasts hours, and some improvement in insulin sensitivity can last a day or more, depending on how long and how hard you were active, so regular activity matters more than one big session.
• The WHO recommends 150 to 300 minutes a week of moderate activity (or 75 to 150 minutes vigorous) and muscle strengthening on two or more days; the ADA advises spreading activity over at least three days and doing strength work two to three times a week.
• In large reviews of trials in type 2 diabetes, exercise lowered HbA1c by roughly 0.4 to 0.7 percentage points on average, with combined aerobic and resistance training performing best; results vary between people and trials.
• Breaking up sitting every 30 minutes and walking for about 10 minutes after meals both lower glucose in trials; small amounts count, and you can start small.
• People who use insulin or sulfonylureas can get low glucose during or many hours after activity, so they should plan with their care team before starting or increasing exercise, and check glucose as advised.
• Very high glucose with ketones (type 1 diabetes), heart symptoms, eye or nerve complications, heat, illness, and pregnancy each call for extra care and individual advice.

Action Points

1. Take a 10-minute walk after your largest meal on most days this week, and note your glucose before and one to two hours after if you check it.
2. Set a sitting timer. Stand up and move for a few minutes about every 30 minutes when you sit for long periods, and note which times of day are hardest.
3. Add strength work on two non-consecutive days. Choose something you can do at home, such as squats to a chair, wall press-ups, or bands, and start with a small number of repetitions.
4. Ask your care team three questions before you increase activity: does my medicine put me at risk of lows, what should I do about food and glucose checks on active days, and do I need a check-up first because of my heart, eyes, nerves, or feet?
5. Prepare a safety kit. Keep fast-acting carbohydrate, water, a glucose meter (if you use one), and identification with you when you are active, and check your feet and shoes before and after.

This book is intended for education and does not replace personal medical advice. If you have diabetes or take glucose-lowering medication, please consult your healthcare team before changing your diet, exercise, or treatment.