Using HR to inform the CTR algorithm reduced significantly the BG decline during exercise ( P = 0.022 ) , indicated marginally lower LBGI ( P = 0.3 ) and fewer hypoglycemic events during exercise ( none vs. two events ; P = 0.16 ) , and resulted in overall higher percentage time within the target range ( 81 % vs. 75 % ; P = 0.2 ) .