Fat oxidation is the mobilisation and utilisation of the fat stores to power the body. Fat is stored as adipose tissue generally around the stomach in males and around the buttocks and thighs in women. Fat storage comes from two major sources, excess carbohydrates that the body stores and from primary fat sources (saturated fats).
To mobilise and burn fat many people believe in the misnomer that high intensity aerobic activity will do this. In fact, high intensity training mobilises glucose stores and actually inhibits the pathways that initiate fat mobilisation. The most effective way to burn fat is through low to moderate intensity exercise and research shows that running (power walking, jogging) yields higher fat oxidation than cycling.
To further enhance fat burn it is advisable to avoid carbohydrates in the hours before exercising as ingestion of carbohyrdates causes the release of insulin to reduce the blood sugar level which in turn inhibits lipolysis (break down of fat). Studies have shown that fasting longer than 6 hours prior to exercise optimazises fat oxidation (although it is not advisable to exercise follow a 6 hour fast).
In summary the best way to burn fat through exercise is to avoid eating carbohyrates in the hour or so prior to exercise. To exercise at a low to moderate intensity and to run/jog as opposed to something like cycling. It should also be noted that ingesting foods high in fat also reduces/inhibits fat, so a well balanced diet is important to assist with any weight loss.
Recent research has been looking at the effects high intensity intermittent exercise (HIIT) has on eating behaviour for weight management in the short and long term. The evidence that is currently being presented suggests that when HIIT is performed 3 times per week for 30-45 minutes, it results in meaningful appetite control. That is, following HIIT exercise participants ate less, equivalent to about 516kJ, which is enough to prevent weight gain and achieve weight loss.