Signs that indicate an effective workout include increased heart rate, muscle fatigue, and a sense of accomplishment. Achieving a target heart rate during cardiovascular activities signifies that the workout is challenging yet appropriate for the individual's fitness level. Post-workout muscle soreness—commonly known as DOMS (Delayed Onset Muscle Soreness)—can also indicate that muscles were sufficiently stimulated. Psychological benefits, such as improved mood and energy levels post-workout, further confirm effectiveness. Collectively, these signs provide valuable feedback on workout intensity and help individuals gauge their fitness progress.