What Lindsey Vonn’s ACL injury underscores about exercising while hurt

While Olympian alpine ski racer Lindsey Vonn chose to compete with a torn ACL, it’s not a good idea for regular folks to exercise with intensity after a serious injury.

​ While Olympian alpine ski racer Lindsey Vonn chose to compete with a torn ACL, it’s not a good idea for regular folks to exercise with intensity after a serious injury. Read More Breaking News, Latest News and Videos | CNN