People who perceive themselves as active cannot identify the intensity recommended by the international physical activity guidelines.

backgroundMany national and international organizations recommend that adults achieve at least 150 minutes of aerobic physical activity (PA) weekly, at a minimum moderate intensity to optimize health benefits. It is unknown if people who consider themselves as active have the ability to identify what is considered moderate intensity.

methodsFifty-one participants who reported achieving a minimum 150 minutes per week at a minimum of moderate intensity PA were recruited through a local fitness facility. All participants underwent a single assessment involving questionnaires, clinical measures, and a treadmill test to measure the ability to perceive moderate intensity. Following the visit, participants' PA level was evaluated by heart rate monitor, while exercising, for 7 consecutive days.

resultsEighty percent of participants overestimated moderate intensity on the treadmill test; they were at vigorous intensity compared to what is considered moderate. Only 11.8% of participants accurately identified moderate intensity; all of them were women (P=0.03), had a high level of education (P=0.04), and knew that moderate intensity was the minimum intensity recommended by health organizations (P<0.01). Only 69.2% of participants reached the aerobic component of the International Physical Activity Guidelines with no significant advantage for those correctly identifying moderate intensity.

conclusionMost people who perceive themselves as active are exercising at vigorous intensity while believing they are at moderate intensity. In addition, in this active sample, one-third of the participants were not reaching the aerobic component of the International Physical Activity Guidelines.