Training errors are the most common cause of overuse injuries. These errors involve rapid acceleration of the intensity, duration, or frequency of activity. Overuse and acute injuries can happen in people who are beginning a workout regimen for the first time, returning to a sport or activity after an extended absence, those trying to make up for lost time after an injury, and those pushing themselves to achieve a high level of participation and fitness in a short amount of time. Coaching proper technique and frequency of exercise is critical in avoiding injuries as a result of working out.