Timing

For those with diabetes, the timing of exercise can have major implications and must be considered – especially for those taking mealtime insulin.

For those who take mealtime insulin, exercising after the meal – with a concurrent reduction in the bolus insulin dose – is best for facilitating weight loss. Post-meal exercise can also help to reduce the glucose “peak” that occurs in the after-meal phase.

Morningtime exercise is associated with the least glucose drop, so hypoglycemia risk is lowest. It is also good for long-term maintenance since daily obstacles don’t get in the way as easily.

However, the most important factor is to choose a time that it preferred and most convenient for the individual. 

Adjustments

Interval training involves prolonging the “challenging” phase of a workout and shortening the “easy” phase. For example, if walking is the exercise, walking at a relatively easy pace for 9 minutes and then 1 minute at a much more challenging pace… and repeat 3 times for a 30 minute workout. Each week, the easy phase is shortened and the challenging phase is lengthened.

This is an effective way to progress, and has been shown to enhance metabolic rate.

Hypoglycemia - Who is At Risk?

ANYONE who takes insulin (basal, or basal and bolus) and insulin secretagogues is at risk of hypoglycemia. This includes those who take sulfonylureas or meglitinides, alone or in combination with other diabetes medications.

Those taking NPH insulin (alone or in premixed insulin formulations) are at the greatest risk for hypoglycemia during exercise, as NPH peaks unpredictably in the middle of the day and night.

Those who take long-acting (basal) insulin are also at increased risk, since the dose required to keep glucose levels stable overnight usually provided too much background insulin during the day.

Fast-acting meglitinides increase the risk of hypoglycemia only when activity takes place within 2-3 hours of taking the medication.

Sulfonylureas are longer acting. Glyburide has been found to present a much greater risk of hypoglycemia than glipizide or glimepiride.