The overall objective of this project is to determine if the intranasal administration of naloxone during exercise will be a novel approach to preserve the counterregulatory response to hypoglycemia experienced the next day in patients with type 1 diabetes. Exercise induced autonomic failure contributes to the development of impaired awareness of hypoglycemia. Treatments that blunt the consequences of exercise induced autonomic failure, such as preserving the post-exercise counterregulatory response to hypoglycemia, may improve awareness of hypoglycemia. Naloxone, an opioid antagonist, is an extremely promising agent. In healthy volunteers, intravenous administration of naloxone during exercise preserved the counterregulatory response to hypoglycemia the following day (1). In this study, investigators will extend the clinical applicability by administering intranasal naloxone to individuals with type 1 diabetes. Specifically, the investigators will use a randomized, placebo controlled, crossover design to administer drug or placebo to patients with type 1 diabetes during acute exercise and assess the counterregulatory response to hypoglycemia the following day. The use of intranasal naloxone is a highly innovative aspect of this proposal. Intranasal naloxone translates readily to clinical use and, as demonstrated by the investigators preliminary data, achieves similar plasma drug concentrations as after IV administration.