When is the optimal time for exercise for iddm using 100 units daily of both humalog (insulin lispro) and lantis?

Any time.: Exercise is so important !, any thing you like any time you want. Juggle your Insulin around it. You may want to start with a regular routine till you get the pattern of your bodies Insulin needs figured out. Take notes!

Basal or Adj insulin: Best time is when only your basal Insulin is on board, to reduce risk of lows. If that doesn't fit ur schedule, u may have to take a negative correction for the dose of Humalog (insulin lispro) that precedes your exercise, ex. Cut down lunch Humalog (insulin lispro) if exercise at 1:30pm. The amt to reduce varies bet'n ppl; exercise, chk before and after so u know ur bg response, and can better guess how much Humalog (insulin lispro) to subtract.