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Updated: May 6

Training is a pleasure for body and mind, but, unlike healthy individuals, type 1 diabetics need extra care when it comes to organizing and managing their workouts.

Type 1 diabetes is a chronic disease that can cause considerable concern in those affected. Unlike a long time ago when insulin administration had not yet been invented, today it is possible to manage the disease and live a normal life. Normality that in a diabetic individual should be characterized by physical exercise and combined with a healthy diet, as these are key factors to keep the disease at bay.

Today I will explain how to best approach your training if you suffer from type 1 diabetes.

Exercise and glycemia in type 1 diabetes

Beyond the beneficial effects that exercise has on the body for both healthy and unhealthy individuals, in type 1 diabetics practicing physical activity decreases the requirement for insulin, the incidence of chronic complications and morbidity, and improves glycemic control, cardiovascular system, quality of life and life expectancy.

However, the glycemic response to physical exercise is not the same for everyone and is affected by multiple factors that determine its progress.

Reduction in blood sugar levels (hypoglycaemia)

During physical activity, the probability that blood sugar levels will drop depends on relative hyperinsulinemia (disproportionate levels of insulin compared to available glucose), on the intensity and duration of training (greater than 30-60 minutes), and on the meal timing (more than 3 hours from last meal).

In a previous article I explained that hypoglycemia during, or in the period immediately following, physical activity, is the greatest risk for a type 1 diabetic who exercises.

If an episode of hypoglycemia has occurred in the 24 hours before training, the counter-regulatory hormonal response is compromised, therefore it is advisable to train with caution.

Furthermore, it is necessary to pay close attention to nocturnal hypoglycemia that can lead to a sense of malaise and tiredness upon awakening, and consequently decreasing the individual's ability to identify further episodes of hypoglycemia.

Control of glycemic levels is essential in type 1 diabetes. Repeated episodes of hypoglycemia impair counter-regulatory hormonal responses, increasing the risk of further episodes occurring in the future.

Increased blood sugar levels (hyperglycaemia)

An increase in blood sugar can be due to excessive carbohydrate intake before and during training, strenuous exercise, and hypoinsulinemia (when the concentration of insulin in the blood is not sufficient to cope with blood sugar levels).

Stable blood sugar levels

Generally, a person undergoing insulin therapy is able to maintain stable blood sugar levels thanks to the right dosage of insulin, adequate nutrition and short-term exercises.

It will therefore be important to define the most suitable insulin therapy (type and dose) with your doctor, know how to manage the administration times and carry out the injection in an area of the body not subjected to exercise.

Furthermore, checking your metabolism and nutrition before and during activity, establishing the right intensity and duration of exercise, and taking into account the temperature of the environment are all key factors that cannot be overlooked if you want to avoid conditions of hypoglycaemia and hyperglycaemia.

Managing exercise with type 1 diabetes

For a type 1 diabetic, having a good knowledge of the disease and the effects of exercise on the body is crucial in order to achieve targets and know when it is time to stop to avoid unpleasant events.

Generally speaking, before starting training (30 minutes before) it is necessary to check blood sugar levels and ketonuria. In the presence of ketonuria (ketone bodies in the urine) it is better to avoid training, while if the blood sugar level is not in the normal range (7-12 mmol/L) you will need to consume carbohydrates.

Glucose synthesized in muscles is approximately 1g/kg/hr. To undertake a one-hour workout, the type 1 diabetic individual will need approximately 30-60g of glucose and if there are signs of discomfort during and after the workout, sugary drinks (fruit juice) or foods (candies, sugar sachets, glucose tablets/gels) should be consumed immediately. Blood sugar levels will also need to be checked after training. Do not inject insulin into areas of the body that are being trained.

These are general indications, let's now look at a couple of more specific situations in which a person undergoing insulin therapy could find themselves.

Unscheduled training

Imagine that today is not a training day, but you feel like training. You get your stuff, go to the gym and start pushing, that's it. For a type 1 diabetics it's not so simple. Let's see how they should behave.

  1. Measure blood glucose levels: if they are close to normal (7-12 mmol/L), eat carbohydrates immediately and eat more after 20-30 minutes.

  2. If your blood sugar is above 12mmol/L it is not necessary to eat carbohydrates immediately and you can start training. However, remember to ingest carbohydrates after 20-30 minutes.

  3. If the training session is intense and long-lasting (30-60 minutes), reduce the post-training insulin dose and increase the carbohydrate intake.

Scheduled training

In a scheduled training session, the type 1 diabetic has plenty of time to organise and prepare the body for physical activity in the days before the session. Let's see below the steps they should follow:

  1. Gradually reduce the insulin dose according to your needs (on the same day or from the previous days).

  2. Start training 1-2 hours after a main meal.

  3. Ingest carbohydrates and, if necessary, measure blood sugar levels in the hours following the training session.


For an individual suffering from type 1 diabetes it is essential to undergo regular medical check-ups and inform/educate the friend with whom they train, the coach or the gym staff about his health condition and the risk of hypoglycaemia (recent episodes, difficulty controlling blood sugar levels).

Training alone is not a good idea. My advice is to always make sure that there is someone present and to keep your cell phone handy. Also remember that the glycemic response varies not only from individual to individual, but also changes based on the environment in which you train and the intensity of the exercise.

Before concluding this article there are some points I would like to highlight whether you suffer from type 1 diabetes or whether the person suffering from it is someone close to you:

  1. During the day, hormonal changes can affect glucose metabolism and the body's response to exercise.

  2. The type of sport can also influence the body's response to exercise: intermittent and complex sports such as football could be problematic.

  3. Avoid exercising within 24 hours of a severe hypoglycaemic episode.

  4. Adjust your diet and insulin dose as you progress through your training program.

  5. In case of significant complications it may be necessary to reduce high impact activities and favor lighter activities.

If you don't suffer from type 1 diabetes, all these precautions might make you think that the life of a diabetic is rather complicated, and indeed it is! In this article I only talked about physical activity, but in everyday life there are many things that a type 1 diabetic must consider and pay attention to.

Luckily, science has made a lot of progress and the disease is now manageable, but unfortunately they have not yet discovered how to prevent it and what the specific cause is. Unlike type 2 diabetes, for which a lot can be done to prevent it. I'll tell you more about this in the next article.

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