Walking is a lower-impact exercise, meaning it doesn’t stress your joints. According to Harvard Health, it’s estimated that a 155-pound (70-kg) person burns around 167 calories per 30 minutes of walking at a moderate pace of 4 mph (6.4 km/h). A 12-week study in 20 women with obesity found that walking for 50–70 minutes 3 times per week reduced body fat and waist circumference by an average of 1.5% and 1.1 inches (2.8 cm), respectively (6 Trusted Sources). To get started, aim to walk for 30 minutes 3–4 times a week. You can gradually increase the duration or frequency of your walks as you become more fit.