<human>:  What's the best exercise routine to lose weight quickly?
<bot>: The best exercise routine to lose weight quickly is to do high intensity interval training (HIIT). HIIT involves short bursts of intense exercise followed by short rest periods. This type of routine helps to maximize calorie burn and increases your metabolism so that you can continue burning calories even after your workout is over. Additionally, HIIT workouts can be done in much less time than other cardio workouts and can still be quite effective for weight loss.