Validity and reliability issues in objective monitoring of physical activity

Major technical advances have occurred within the last 10 years in the field of physical activity monitoring.The biggest one is real-time data acquisition, and thedevelopment of computer microchips that allow vastamounts of information to be stored and later recalled.It is evident that no single motion sensor will provide anaccurate estimate of energy expenditure across all activities.Future directions for research include the use ofcombined instruments such as an accelerometer plusquestionnaire, multiple motion sensors, or dual HRmotionsensor technology. © 2000 by the American Alliance for Health, Physical Education, Recreation and Dance.