February 01, 2007
In last month's CrossFit Journal, I said that we must always focus on performance when assessing fitness. Specifically, I argued that body fat measurement not only is futile (from an accuracy standpoint) but, more importantly, is irrelevant to athletes focused on what they can do rather than how they look. That said, fat loss is still a major and valid concern for many trainees out there, and the fitness industry is full of schemes and strategies for burning body fat.
One of these supposedly scientific nuggets of accepted "wisdom" is the belief, espoused by many personal trainers and reflected in the preset programs on most cardio machines, that the best way to lose fat is to work at a moderate intensity. A version of the graph above appears on the walls of innumerable gyms and training studios across the United States and Canada, graphically illustrating the supposedly "right" exercise intensity (as a percentage of an individual's mathematically estimated maximum heart rate) for maximizing fat loss. But it is not an accurate representation of the true picture. oxygen per min) will burn a greater percentage of fat than when working at the higher intensity.