The slendertone abs is clinically proven to tone and firm the bas in just 4 weeks ems technology has been used for over 50 years in sports and medical environments to strengthen and rehabilitate muscles the slendertone abs patented technology recruits all the abdominal muscles this includes the superficial rectus abdominus and external obliques as well as the deep internal obliques and traversus abdominus muscles independent clinical study has proven after 4 weeks use 49 increase in ab