A recent study in the British Journal of Sports Medicine analyzed all research published in English/Spanish/Portuguese via a systematic review and meta-anaylysis to determine if HIIT (high intensity interval training) or moderate-intensity continuous training was more effective for fat loss. All of the studies reviewed had to be human trials, original research, minimum of 4 weeks duration and directly compare HIIT with moderate training. They looked at over 40 quality studies (of the 786 published, the rest were not considered scientifically sound). The results concluded that HIIT results in 28.5% GREATER reduction in absolute fat mass than moderate training. So, if you are short on time and need results, focus on a clean diet, avoiding processed foods and sugar (no need for diet fads) and consider HIIT workouts for 20 minutes 3-4 days per week and watch the fat melt away. No more wasting hours in the gym!!