Which Type of Exercise Is Best for Weight Loss?

Exercise is an important component of any weight management programme — but its role is often misunderstood. Exercise alone rarely produces large amounts of weight loss; its greatest value lies in preserving muscle mass during weight loss, improving metabolic health, and supporting long-term weight maintenance. Understanding which types of exercise are most effective for different goals can help you make better use of your time.

Aerobic exercise

Aerobic exercise — walking, running, cycling, swimming, and similar activities — burns calories during the session and improves cardiovascular fitness. The NHS recommends at least 150 minutes of moderate-intensity aerobic activity per week for general health.

For weight loss, higher volumes of aerobic exercise produce greater results. A 2013 review in Obesity Reviews found that aerobic exercise programmes producing an energy expenditure of 2,000 kcal per week or more led to clinically meaningful weight loss. However, the body adapts over time — both by becoming more efficient and by compensating with reduced activity outside exercise sessions — which limits the long-term effect on weight.

Resistance training

Resistance training — using weights, resistance bands, or bodyweight exercises — builds and preserves lean muscle mass. This matters for weight management because muscle tissue is metabolically active: each kilogram of muscle burns approximately 13 kcal per day at rest, compared to around 4.5 kcal per kilogram of fat.

When people lose weight through diet alone, a significant proportion of the weight lost is muscle. Adding resistance training to a weight loss programme preserves muscle mass, which helps maintain resting metabolic rate and supports long-term weight maintenance.

High-intensity interval training (HIIT)

HIIT alternates short bursts of intense effort with recovery periods. Research suggests it produces similar or greater improvements in cardiovascular fitness and insulin sensitivity compared to moderate-intensity continuous exercise, in less time. A 2017 meta-analysis in Sports Medicine found that HIIT reduced total body fat and abdominal fat more effectively than moderate-intensity exercise when matched for time.

HIIT is not suitable for everyone — it places significant demands on the cardiovascular system and joints. A doctor-led assessment can help determine whether it is appropriate for you.

What does the evidence recommend?

• Combine aerobic exercise with resistance training for the best outcomes
• Aim for at least 150–300 minutes of moderate aerobic activity per week
• Include two or more resistance training sessions per week
• Choose activities you enjoy — adherence matters more than the type of exercise
• Increase daily movement (walking, taking the stairs) alongside structured exercise

For personalised exercise guidance as part of a doctor-led weight management programme, speak to the Weight Loss Wales team.