It’s not just about diet (or medication): how to tackle obesity through exercise

Physical exercise is one of the most powerful ways to counteract the impact of obesity on health

by Maria Rita Montebelli

16 June 2026

3' min read

Translated by AI

Versione italiana

Key points

From HIIT to weights to aerobics: all the benefits of exercise
Adipose tissue: a dynamic organ open to dialogue
Effects of obesity and physical exercise on the liver
Effects of obesity and exercise on skeletal muscle
Exercise: a complement to GLP-1 drugs and bariatric surgery

3' min read

Translated by AI

Versione italiana

Obesity is not just being overweight: it is a complex disease that profoundly alters the functioning of key organs such as adipose tissue, the liver and muscles, increasing the risk of diabetes, fatty liver disease (MASH) and cardiovascular disease. The good news is that physical activity acts as a genuine ‘metabolic medicine’. As highlighted in a review recently published in Endocrine Reviews , exercise improves insulin sensitivity, reduces inflammation, protects the heart and liver, makes muscles metabolically ‘smarter’ and helps restore many of the mechanisms compromised by obesity.

Its benefits go far beyond weight loss: regular exercise tackles the root causes of the condition and enhances the effectiveness of drug treatments and bariatric surgery. In other words, physical exercise is one of the most powerful tools for counteracting the impact of obesity on health.

From HIIT to weights to aerobics: all the benefits of exercise

Whether it’s high-intensity interval training (HIIT) or moderate aerobic activity, exercise ‘reactivates’ the muscles, boosting the mitochondria and the body’s ability to burn fat as fuel. In people with fatty liver, it reduces the build-up of lipids in the liver, improves insulin sensitivity and reduces inflammation. Physical activity also helps to reduce body weight, blood glucose levels and blood pressure, thereby counteracting the main cardiovascular risk factors. In people with type 2 diabetes, aerobic exercise improves insulin sensitivity by 20 per cent and reduces glycated haemoglobin levels by 0.8 percentage points.

Adipose tissue: a dynamic organ open to dialogue

Rather than simply being a store of fat, adipose tissue is a fully-fledged metabolic and endocrine organ, capable of communicating with the whole body. In obesity, this system is compromised: fat cells increase in size and number, the tissue becomes inflamed and the mitochondria – the cells’ ‘powerhouses’ – become less efficient, producing an excess of free radicals that promote oxidative stress and insulin resistance.

Physical activity, on the other hand, reduces inflammation, improves insulin sensitivity, ‘trains’ the mitochondria, making them more efficient, and promotes the production of beneficial molecules that improve metabolism. Furthermore, it alters the profile of hormones produced by fat tissue: it reduces leptin, which is often elevated in obesity, and increases adiponectin, which has anti-inflammatory and anti-diabetic effects. Just a few sessions of aerobic exercise are enough to significantly increase adiponectin levels, demonstrating just how quickly physical activity can trigger changes that are beneficial to health.

In other words, exercise does more than just ‘burn calories’: it helps to reprogramme adipose tissue, turning it into an ally of good health.

The effects of obesity and physical exercise on the liver

In obesity and metabolic liver diseases such as NAFLD and MASH, the liver undergoes profound changes in its metabolism of sugars and fats, with increased lipid production and accumulation, inflammation and reduced insulin sensitivity. These changes promote the progression of liver damage.

Physical exercise is effective in counteracting these changes. Significant benefits have been observed with aerobic training, strength training and high-intensity interval training (HIIT), even after just a few weeks.

In short, exercise not only improves overall metabolic health, but also has a significant protective effect on the liver, helping to slow down or prevent the progression of obesity-related liver diseases.

Effects of obesity and exercise on skeletal muscle

Skeletal muscle is one of the main organs involved in regulating metabolism and utilising glucose. In obesity, however, its ability to respond to insulin is reduced, making it difficult to remove glucose from the blood. Furthermore, there is an accumulation of fat within the muscle fibres and a reduction in the efficiency of the mitochondria – the ‘powerhouses’ of the cells – which impairs energy production.

Physical exercise counteracts these effects. Aerobic and strength training improve insulin sensitivity, increase the muscles’ utilisation of glucose and fat, stimulate mitochondrial function and reduce inflammation. Furthermore, active muscles release beneficial substances (myokines), which improve metabolism and the health of the whole body.

Exercise: a complement to GLP-1 drugs and bariatric surgery

GLP-1 receptor agonist therapies (such as liraglutide, semaglutide and tirzepatide) are currently one of the most effective approaches to treating obesity. However, these benefits tend to diminish (or disappear) once treatment is stopped.

The latest evidence shows that combining these medicines with physical exercise increases their effectiveness. Physical activity enhances weight loss, improves insulin sensitivity, body composition and overall metabolic health, whilst also helping to preserve lean body mass and bone mass and to sustain the benefits achieved for longer. This makes exercise a vital complement to modern anti-obesity therapies.

Even bariatric surgery, one of the most effective treatments for severe obesity, can, in the long term, be associated with a loss of muscle mass and strength, nutritional deficiencies and the regaining of some of the weight lost.

Physical activity, including aerobic and strength training, is of great benefit both before and after surgery. Exercise helps to preserve muscle mass, further reduce body fat, improve physical fitness and help maintain a healthy weight over time.