On this page I’ve put together some of my experiences of training and racing with T1 diabetes.

IMPORTANT NOTE: The information is based on what works for me – I’m not saying it will be right for everyone, but I’ve shared it to give an idea of how I approach training sessions and competitions.

If you are just starting out, you will probably make some mistakes – be prepared for these and make sure that you learn from them!

Tips for Type One Athletes:

  • Make sure you have clean fingers before testing your BG levels. I once tested after I had consumed an energy gel – the gel was still on my fingertips and I tested higher than I was. Later in that run I was taken to the ambulance with hypoglycemia, hypotension and hypothermia. 
  • Always take enough carbohydrates for the entire training session… sometimes more. When cycling I make sure I have at least 2 water bottles (at least one filled with Horley’s Replace), a couple of gels and some CHO bars. When I run I use either a fuel belt with a couple of bottles and gels or a full Camelbak and some gels. When I swim I have gels at the end of the lane and a bottle with Horley’s Replace or Powerade. My husband often puts a couple of extra gels in his pocket – just incase.
  • Wear a Medic Alert bracelet (or similar) that states “I have Type 1 Diabetes”.  I have a couple of bracelets from MedAware and one from Road ID.  The details on the medical ID tag include my name, my husband’s phone number, my parents’ phone number and TYPE 1 DIABETES ON INSULIN PUMP.
  • When you are comfortable, tell all of you friends and training partners that you are diabetic.
  • If you can, train with a mobile phone.

How do I avoid ‘hypos’?

Testing is essential for quality athletic performance.  You should always test before, during and after training and racing.  Your BG levels need to be at a safe starting point to avoid hypoglycemia.  An ideal starting BG level is between 5 – 10mmol (90 – 180).  If your BG level is higher than 15mmol (270), you should test for Ketones.  It is also suggested that you shouldn’t train at this time however I train regardless of my starting BG level. The reason medical professionals don’t recommend training when your BG levels are above 15mmol (270) is because your body is sometimes forced to burn fat for fuel, as is the case when insulin levels are too low, toxic ketones can build up in the blood, and that can lead to ketoacidosis.  Similarly, when your BG levels are below 6, you should eat some carbohydrates. Knowing your BG level can help you to make other decisions about your training like how much to reduce your basal rates by and how much carbohydrates to consume during training. It’s a good idea to record your test results so that you are able to see patterns in your BG levels after different training. This will also help you to make changes to your reductions in other training sessions.

Reduction of basal rates for insulin pump users is another way to optimize your athletic performance and avoid hypoglycemia when training and racing. We reduce our basal rate so that when we exercise we don’t have too much insulin on board and therefore reduce the risk of hypos. The duration, intensity and terrain will affect your insulin absorption so you need to make reductions according to your training and BG levels. You will also need to consider the time of day, when you last had insulin and pre-exercise carbohydrate consumption. 

I make small bolus rate reductions for meals I have with an hour of exercise. I also commence a temporary basal rate for the entire duration of training. Once I stop training/racing I go back to my normal basal rate.       

Heidi-Jane’s Insulin Adjustments

Type of Exercise

Insulin Changes

Insulin Reduction

CHO Consumption

Swimming (60 – 90mins)

Pump off

1 x gel (if needed)

Cycling (90 – 240mins)

Lower my pump basal rate for the entire ride.

>10mmol (180) reduce to 70 – 90%
<10mmol (180) reduce to 50 – 60%

1 x bar & ½ bottle of Horleys Replace per/hour

Running (<60mins)

Lower my pump basal rate for the entire run.

>10mmol (180) reduce to 80%
<10mmol (180) reduce to 70%

1 x gel (if needed)

Running (90 – 240mins)

Lower my pump basal rate for the entire run.

>10mmol (180) reduce to 60 – 80%
<10mmol (180) reduce to 40 – 50%

1 x gel per/hour

Sprint Triathlon

Pump off

1 x gel & ½ x bottle of Horleys Replace per/hour

Olympic Triathlon & Half Ironman

Pump off for the swim. Reattach for cycle and run.
Lower my pump basal rate for entire race.

>10mmol (180) reduce to 70 – 80%
<10mmol (180) reduce to 50 – 60%

>1 x gel & 1 x bottle of Horleys Replace per/hour

Ironman Triathlon

Pump off for the swim. Reattach for cycle and run.
Lower my pump basal rate for entire race.

0% for swim
60 - 70% for the cycle
40 - 50% for the run

1 x gel, ½ x bar/banana and ½ x bottle of water/Horleys Replace per/hour.

Caffeine half way through the bike.

Food and fluid intake while training is critical for training and racing. For endurance sports like triathlon, you should consume between 15 – 50grams of carbohydrates per hour.  This may vary according to the intensity and duration of training and racing.  In Ironman I consume 40 – 50grams of carbohydrates per hour.  Some examples of carbohydrates I would eat are gels, bars, bananas, jam sandwiches, and sports drinks.

Sports Resources for People with Type 1 Diabetes: