1. Sprint exercise resulted in 3 times more fat loss while expending 1/2 the calories compared to those who performed aerobic exercise. (Tremblay)
2. Low intensity aerobic exercise participants lost lean body mass. Over the long term, reduced lean body mass results in a lower resting metabolic rate and thus reduces the ability to burn fat. (Mouglos)
3. One study found that the addition of 4 hours of aerobic exercise per week had no effect on weight loss, while another found performing 45 mins of aerobic exercise 5 days per week for 12 weeks had no effect over dieting alone. (Van Date, Utter)
4. Twenty minutes of interval/sprint training, 3 times per week for 15 weeks led to greater fat loss compared to steady state aerobic exercise. (Trapp and Boutcher)
So is cardio pointless? Even thought it pales in comparison to other modes of exercise in the ability to burn fat, cardio is still effective. However, cardio should not be done alone as one's only form of exercise. Cardio is effective in promoting CNS recovery from intensive exercise and should be a small part of an exercise program that includes proper eating, muscle-building resistance training, and fat-burning intervals.