For most sporting activities performance will be closely linked to matching nutrition intake with energy expenditure. Insulin is one of the main keys to this metabolic process. In a normally functioning pancreas it is released or withheld in an automatic fashion depending on blood glucose levels.In a person with diabetes who is dependent upon the delivery of insulin from subcutaneous absorption this moment to moment control of blood sugar is impossible to achieve although a reasonably close match has proved possible with fine tuning of food and insulin delivery.
In order to optimise performance you will need to assess your requirements for both long acting background insulin and your pre meal short acting insulin.
In pre-planning for a vigorous activity, the insulin quantity may have to be significantly reduced the night before. If you are already using a brand of pre-mixed insulin, then you will find this task difficult. Ask your physician to consider changing to multiple injections, which will include separate shots of long and short acting insulin.
One of the main challenges during sporting activities is the balance between food and insulin. One has to take into account the different requirements needed at any given time. These will vary upon the intensity of training and the stress of the competition as well as the need to replenish the glucose stores within the muscles.
Regular and constant monitoring is the key to your understanding of your body in this situation. It is your navigation tool and a way to predict your energy and insulin requirements.