Exercise for obesity: a gentle, joint-friendly way to start and keep going

What exercise can and cannot do

It helps to be clear from the start, because unrealistic promises are the main reason people stop. The US Centers for Disease Control and Prevention (CDC) explains that most weight loss comes from eating fewer calories, and that losing weight with activity alone takes a high amount of it unless the diet changes too. Activity is, however, what helps most to keep weight off once it has been lost.

The American College of Sports Medicine (ACSM) position stand, led by Donnelly, gives the figures behind this:

• 150 to 250 minutes a week of moderate activity helps prevent weight gain and gives a modest weight loss on its own.
• More than 250 minutes a week is associated with clinically significant weight loss.
• Combined with a moderate reduction in what you eat, 150 to 250 minutes a week improves weight loss.
• Strength training does not speed up weight loss, but it may increase lean mass and the loss of fat mass.

The same review recalls that a reduction of 3 to 5% of body weight already lowers health risk. For someone weighing 120 kg, that is 4 to 6 kg. It is a realistic first milestone, and a far better one than an ideal weight chosen from a chart.

The benefits that come before the scales move

Exercise changes the body before it changes the number on the scales. In a meta-analysis of 13 trials in adults with overweight or obesity, Wewege and colleagues found that both interval training and steady moderate training reduced whole-body fat mass and waist circumference, without accompanying changes in body weight. Participants trained for about ten weeks, three times a week.

The ACSM review adds that endurance or strength training improves health risk even without weight loss. In practice, this means that a month of regular walking can improve your fitness, your waist and your blood markers while your weight stays flat. Measuring your waist, as described in our guide to the waist-to-height ratio, gives a fairer picture than weight alone.

Choosing activities that protect your joints

The best activity is the one you can repeat several times a week without pain. With a higher body weight, start with forms of movement that limit impact:

• Walking, on flat ground at first, in supportive shoes. The NHS describes a brisk walk as about 3 miles an hour, a pace at which you can talk but not sing. See walking to lose weight.
• Cycling, on a stationary bike or on quiet roads, which supports your body weight on the saddle. See cycling to lose weight.
• Swimming and water exercise. According to the CDC, people are able to exercise longer in water without increased joint or muscle pain. See swimming to lose weight.
• Strength exercises with body weight, light dumbbells or machines: rising from a chair, wall push-ups, rowing with a resistance band.

Running and jumping can come later, once the body has adapted and if you want them. There is no rule that says they must come at all.

How to start: the first eight weeks

The principle is to begin below what you think you can do, so that you finish each session wanting more. Here is an illustrative progression, to adapt to your own starting point:

1. Weeks 1 and 2: walk or cycle for 5 to 10 minutes, once or twice a day, on five days of the week.
2. Weeks 3 and 4: extend each outing to 15 minutes, and add one short strength session of four or five exercises.
3. Weeks 5 and 6: reach 20 to 30 minutes per outing, with two strength sessions a week.
4. Weeks 7 and 8: approach 150 minutes a week of moderate activity, the minimum the WHO recommends for all adults.

The intensity to aim for is moderate: your breathing speeds up, you can still speak in sentences, you could not sing. The CDC uses exactly this talk test. The NHS, on its obesity page, goes further and suggests being active for 45 to 60 minutes a day, which you can break into shorter sessions. Treat that as a direction of travel, not a starting point.

Strength training: the part people skip

When you eat less, part of the weight lost can be muscle. Strength work pushes back against that, and muscle is what keeps you able to climb stairs, carry shopping and get up from the floor. The WHO recommends muscle-strengthening activity on at least two days a week for all adults.

Choose movements you can do with control and without joint pain: sit-to-stand from a firm chair, step-ups on a low step, push-ups against a wall or a table, rows with a band. Two or three sets of 8 to 15 repetitions are enough to begin. Our guide to strength after 40 explains how to progress.

Safety first

Talk to your doctor before you start, especially if you have heart disease, diabetes, high blood pressure, joint pain, breathing problems or take regular medication. Stop and seek medical advice straight away if you feel chest pain, unusual breathlessness, dizziness or palpitations during effort.

A few other precautions help a great deal:

• Wear shoes that support your feet, and check your feet after each walk if you have diabetes.
• Drink water during longer sessions, especially in the heat.
• Expect some muscle soreness in the first weeks; joint pain that lasts or gets worse is a reason to stop and get it checked.
• Ask your doctor about specialist support. The NHS explains that a GP can refer people to weight management programmes, which can include exercise classes and healthy eating advice.

Make it a habit with Never Skip Club

What makes the difference over a year is not the perfect session, it is the number of weeks in which you kept moving. Create your free account on Never Skip Club and launch a guided Easy session of 20 or 30 minutes at home, with the exercises shown in animation. Then invite two to six friends into a crew with a gentle rhythm, for example three sessions a week for a month: the ranking rewards regularity, not performance, so everyone plays on equal terms. If you would like an expert to adapt the movements to your joints, find a coach from our network, or sign in if you already have an account.