Stretching if you feel tight at all but as others said, sudden movement... I did both of mine partially playing volleyball on cold sand... felt like something kicked me in the back of the ankles... mine were only 10-15% tears and I had to do a lot of leg lifts feet on end of stairs.. knots in my achilles eventually went away... but took a long time... just not sure about stress professional athletes put on them and how long for it to heal... for Tre there is always hockey.. Sabres could use a good back up goalie.