Physical activity is effective in improving insulin sensitivity in an obese and type 2 diabetic population (T2D). However, most Americans do not adhere to the ACSM exercise guidelines. The effectiveness of different exercise modes to improve insulin sensitivity in an obese and T2D is unknown. Therefore, the purpose of this study was 1) to compare the effects of aerobic, resistance, and combination exercise training and 2) to determine the role of volume and intensity (aerobic) and repetitions and sets (resistance) on exercise induced improvement in insulin sensitivity in an obese and T2D population. 73 studies were used for this review. Metaanalysis methods were used to evaluate the role of moderators, such as volume, intensity, number of sets and repetitions, in the effectiveness of exercise training to improve insulin sensitivity. Aerobic, resistance and combination exercise training were effective modes in improving insulin sensitivity in obese and T2D (Z=5.43, p<.0001). Volume and intensity during aerobic exercise did not have an effect on degree of improvement in insulin sensitivity (Q=1323.6, p<.0001). During resistance exercise, greater number of sets resulted in a greater improvement however, number of repetitions did not have an effect on improving insulin sensitivity (Z=3.1370, p=0.0017). Although traditional aerobic exercise is an effective training method in improving insulin sensitivity in obese and individuals with T2D, resistance and/or combination exercise provide beneficial alternative training methods to improve insulin sensitivity. While prescribing resistance exercise, focusing on number of sets (3 or more), rather than number of repetitions, should be emphasized to improve insulin sensitivity.