Athletes who are insulin-requiring and insulin-dependent diabetics undergoing high levels of activity over extended period of time

The proportion of time spent in euglycemia zone as well as hypoglycemia zone will be determined from the system glucose readings, particularly during subject's high levels of activity. Longitudinal data analysis methods will be used to assess the within-subject and between-subject effects of the glycemic control for the study population.

The objectives of the study are to evaluate the Dexcom G4 system utility and usability during high levels of activity and home use. The assessments may be evaluated by, but are not limited to, the following:

• Number and duration of sensors used by subject
• Percentage of CGM system communication during wear
• Percentage of CGM system glucose reading during wear
• Incidence of System prompts and error messages recorded in the receiver