The world continues in the midst of a significant public health problem related to obesity and inactivity. This epidemic has far-ranging consequences on the workforce of the world and on our children, and shows no signs of slowing down in the near future.

A significant amount of research has been performed on the effects of exercise for the reduction of body weight. A literature review was performed to address the effects of aerobic exercise, strength training, and high intensity interval training (HIIT) on obesity and weight loss.

Most studies indicate that exercise alone has a small effect on body weight reduction independent of caloric restriction. When combined with dietary restriction, exercise has a synergistic effect and enhances weight loss beyond the effect of diet alone. Exercise also has been shown to have significant beneficial effects on cardiovascular and metabolic risk factors independent of actual weight loss, and losing just a small amount of weight can have a significant beneficial effect. Genetic factors related to obesity have been found to be positively modified when individuals incorporate physical activity into their lifestyle. Sitting time also appears to be an independent risk factor for the development of metabolic risk factors; individuals who spend more time sitting and watching television have worse metabolic profiles, even if they achieve the recommended amount of physical activity per week. High intensity interval training has been shown to be a safe, effective, and well-tolerated mode of exercise in the obese population, and compliance may be better than continuous moderate duration exercise.

Continuous moderate intensity aerobic exercise has a synergistic effect with diet to enhance weight loss. Resistance training has significant cardiovascular and metabolic effects independent of weight loss. High intensity interval training is effective, time efficient, and well-tolerated in the obese population.