Wearable motion sensors that measure biomechanics during exercise and communicate measurements to mobile electronic devices and personal computers capable of evaluating form and technique, assessing performance, and providing exercise feedback via software applications; motion sensors for use in detecting and analyzing three dimensional movements over time to track exercise activity and progress, communicate detected data to mobile electronic devices and personal computers that provide exercise feedback via software applications, store historical performance data on a cloud network, and provide comparisons of performance relative to other athletes to motivate users to exercise; electronic motion sensors for detecting and analyzing movements during exercise and wirelessly communicating data on movements to mobile electronic devices and personal computers to identify risk of injury, detect musculoskeletal imbalances during exercise, and provide real-time fitness coaching through software applications; wearable motion sensors with video cameras that record and measure performance during exercise and communicate data to mobile electronic devices and personal computers that provide a user with exercise feedback via software applications; motion sensors for use in attachment to clothing for detecting and analyzing three dimensional movements over time to track exercise activity and progress, communicate detected data to mobile electronic devices and personal computers that provide exercise feedback via software applications, store historical performance data on a cloud network, and provide comparisons of performance relative to other athletes to motivate users to exercise; electronic motion sensors for use in attachment to clothing for detecting and analyzing movements during exercise and wirelessly communicating data on movements to mobile electronic devices and personal computers to identify risk of injury, detect musculoskeletal imbalances during exercise, and provide real-time fitness coaching through software applications; all of the foregoing being sensors for use in measuring fitness and not for medical use