The investigators hypothesise that reducing basal insulin dose (Glargine, Lantus, Sanofi-Aventis, or Detemir, Levemir, Novo Nordisk), whilst employing current carbohydrate feeding and rapid-acting insulin dose recommendations will protect patients with type 1 diabetes from early- and late-onset hypoglycaemia following evening time exercise.

Inclusion Criteria:

• Aged between 18-50 years old (male or female).
• Free from any diabetes related complications (apart from mild background diabetic retinopathy).
• HbA1c <8.5%.
• Not taking any prescribed medication other than insulin, and treated with a stable insulin regimen composed of a combination of slow/long acting insulin (glargine or detemir) and fast-acting insulin analogues (lispro or aspart), for a minimum of 6 months before the start of the study.
• Demonstrate normal cardiac function in response to exercise.

Exclusion Criteria:

• Aged younger than 18, or older than 50 years.
• Suffering from, or diagnosed with a diabetes related complication (apart from mild background diabetic retinopathy).
• HbA1c >8.5%.
• Currently taking prescribed medication, and not currently treated with a stable basal bolus regimen composed of a combination glargine or determir, and lispro or aspart for at least 6 months before the start of the study.
• Failure to demonstrate normal cardiopulmonary responses during exercise, or have a medical condition which could prevent completion of exercise or be exacerbated because of.