Justin Timberlake and Jessica Biel are literally freezing their butts off.<br /><br />The 'Rock Your Body' singer and his actress wife are fans of cryotherapy, <br /><br />a new weight-loss technique which involves standing in a tank at subzero temperatures for three minutes in order to burn calories.<br /><br />Standing in the icy tanks prompts the body to go into overdrive to keep warm burning up to 800 calories at a time.<br /><br />Cryotherapy is also thought to fight inflammation and an insider revealed Justin is also using the treatment <br /><br />to help with muscle pain during his intense rehearsals for his upcoming tour.<br /><br />Good luck Justin!
