Your time is precious — and limited. So when it comes to working out, it’s not uncommon to wonder: what exercise burns the most calories?

Exercise scientists have rigorously studied the amount of energy people expend during different types of exercise, and they’ve determined which workouts are best for burning calories. The thing to keep in mind: the more muscles you engage and the harder (and longer) you push those muscles, the more energy your body will churn through, says Dr. Tim Church, an exercise researcher and a professor of preventative medicine at Pennington Biomedical Research Center at Louisiana State University. So in order to maximize the number of calories you’ll burn, “you want an exercise that uses both lower and upper body muscle groups and is performed at a high intensity,” Church says.

You might therefore expect something along the lines of CrossFit or Tabata-style interval training to burn the most calories. And you may be right.