21. Grade Level Physical Education Standards 7th Grade : Standard 4 4.4 Explain the effects of physical activity on heart rate during exercise, during the recovery phase, and while to body is at rest. 6th Grade : Standard 3 3.6 Monitor the intensity of one’s heart rate during physical activity. Standard 4 4.5 Explain methods of monitoring heart rate intensity. 4.6 List the long-term benefits of participation in regular physical activity.