- https://www.verywellhealth.com/four-phases-of-cardiac-rehabilitation-2696089
2. http://circ.ahajournals.org/content/57/3/549.abstract
3. none
4. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3116747/
5. https://www.healthline.com/health/what-are-mets#examples
6. none
7. none
8. none
9. none
10. https://www.healthline.com/health/what-are-mets#examples
11. https://www.heart.org/en/health-topics/heart-failure/what-is-heart-failure/classes-of-heart-failure
12. http://circ.ahajournals.org/content/101/7/828.full
13. none
14. none
15. none
16. none
17. none
18. https://www.webmd.com/diet/features/the-step-diet
19. none
20. http://emedicine.medscape.com/article/1827089-technique
21. http://emedicine.medscape.com/article/1827089-technique
22. http://emedicine.medscape.com/article/1827089-technique