The artificial pancreas, a device used for automatic delivery of insulin and glucagon subcutaneously to subjects with type 1 diabetes, is paving the way to revolutionize the management of this disease. Already, the benefit of improved glycemic control compared to current open-loop pump therapy has been demonstrated in several trials. The investigator's group has shown that artificial pancreas algorithm dual hormone system effectively manages blood glucose in a clinic setting and the investigators have specifically shown great progress using glucagon to reduce hypoglycemic episodes outside of exercise. The investigators most recent inpatient study, as yet unpublished, shows that adjusting insulin and glucagon delivery during closed loop treatment, after announcing exercise, effectively reduces mean time below a glucose level of 70 mg/dl when compared to closed loop control without adjustments. The investigators utilized initial open-loop data from this study to help devise dosing changes for the artificial pancreas algorithm.