During each week, the subject will wear one subcutaneous DexcomTM G4 or DexcomTM G4 Share continuous glucose monitoring (CGM) system, one activity monitor- ActiGraph wGT3X-BT or ActiGraph GT9X, one insulin pump (subject's own pump) and one Samsung Galaxy S4 phone loaded with two applications- meal memory and moves. The CGM system will provide sensed glucose data every 5 minutes. The CGM data will be blinded to the patient to prevent any abrupt changes in behavior. The accuracy of the sensed data will be obtained by reference measurements of capillary blood glucose. The activity monitor will be secured on the dominant wrist and uses an accelerometer to collect movement data at a high frequency (80Hz). The activity monitor measures both motion and ambient light, this data would be used to determine the various sleep quality measures. The subject's insulin dosage information from the pump will be downloaded for data analysis purposes. The subject's daily meal intake (photographic log and note diary) and daily movement pattern information will be downloaded from the phone. During the 4 exercise intervention visits, subject's heart rate, accelerometry information from the torso and oxygen consumption measured breath by breath may be collected for data analysis purposes.