An indicator of exercise intolerance is just a sign that the body is not coping with exercise.
Exercise intolerance is a condition of inability or decreased ability to perform physical exercise at what would be considered to be the normally expected level or duration. It also includes experiences of unusually severe post-exercise pain, fatigue, nausea, vomiting or other negative effects. Exercise intolerance is not a disease or syndrome in and of itself, but can result from various disorders.
You can find out more in the 'SISFFIT006 Conduct fitness appraisals' unit.