Understanding the Impact of Exercise on Blood Glucose Levels in Type 1 Diabetes

Exercise plays a crucial role in managing blood glucose levels for individuals with type 1 diabetes. However, the effect of physical activity on glucose concentration can vary significantly based on several factors, including insulin levels, carbohydrate intake, and the intensity and duration of the exercise. It's essential for people with diabetes to understand these dynamics to maintain optimal glycaemic control.

When engaging in prolonged exercise lasting more than 30 to 60 minutes, blood glucose concentrations typically decrease. This reduction can be exacerbated if an individual takes too much insulin or consumes too little carbohydrate before their workout. This underscores the importance of careful pre-exercise planning and monitoring to avoid hypoglycemia during and after physical activity.

Conversely, the blood glucose levels may remain stable during short or mild-intensity workouts. In these scenarios, proper nutrition, such as having appropriate snacks or making insulin adjustments beforehand, can help maintain equilibrium. For many, striking this balance is key to enjoying the benefits of exercise without risking swings in glucose levels.

However, intense physical activity can lead to an increase in blood glucose concentrations. This is particularly true if an individual has not taken enough insulin or has consumed excessive carbohydrates beforehand. High-intensity exercise stimulates the release of catecholamines and cortisol, hormones that counteract insulin's effects, resulting in elevated glucose levels.

For effective management of diabetes, monitoring blood glucose is vital. Individuals are typically encouraged to check their levels before meals or approximately two hours post-meal, often conducting this check between two and four times a day. This practice helps in assessing the effectiveness of both basal and mealtime bolus insulin and allows for necessary adjustments in medication and diet.

Long-term glycaemic control is gauged using measures such as glycated hemoglobin (HbA1c) and fructosamine, which provide insights into average blood glucose levels over weeks or months. HbA1c serves as a crucial metric for diabetes management, as it correlates with the risk of microvascular complications. Target HbA1c values usually range from 6.5% to 7.5%, but these goals should be personalized based on each individual's clinical circumstances.