You will not necessarily burn more fat using a ‘fat burn’ program on the treadmill which keeps you in an intensity of 50 – 60% of your max heart rate. There is evidence to show that exercising at a light to moderate range burns more fat than strenuous exercise as the body has greater access to use fat as a fuel during these lower intensities. As you can see in the table below, a percentage of fat is used during all intensities of exercise, but at different rates. Because the rate of fat use is slow during light to moderate exercise, it is important to increase the duration of your exercise session – minimum of 30 minutes progressing to 60 minutes.
I have helped numerous clients succeed in significant weight loss journeys that involve losses of over 20-30 kg in body fat over the space of 1-2 years or more. I actually find such longer term journeys more rewarding as they allow me to teach my clients about the impact of nutrition and lifestyle habits on their physiology. This not only helps them, but also helps those closest to them as well.