Yes, we can do this! We know we can. We have done and will do so again. Let’s start our talk regarding this medical condition and exercise on the right foot. Or the left foot, if that is your sporting preference!
We are going to find challenges along the way; the threat of hypoglycaemia, the weird hyperglycaemic occurrences, the differing patterns and timings varying from one activity to another, one week to another. Though these challenges bring much for frustration, impacting our performances, the fear-factors on more serious hypos, these are also key lessons to be learnt of our body and condition.
A core foundation for any athlete to develop from isn’t in raw talent, its within mental strength, fuelling the growth to be:
Striving to adapt our mentality when it comes to type 1 diabetes and exercise – in facing all we need to uncover and understand of our bodies – is a formula for success when met with key guidelines on the varying impacts of blood glucose levels before, during and after activity.
Considering Types of Exercise:
Aerobic vs Anaerobic. We have to deal with a lot of scientific terminologies with diabetes: basal and bolus, infusion sets and cannulas, hyperglycaemia and hypoglycaemia to name a few… so why not add more to the mix inside our big diabetes-calculating brains?
Think “cardio,” aerobic exercise is cardiovascular conditioning where your heartrate rises (as it would in any activity) but at a steady rate. This type of exercise is famed for keeping your heart, lungs and circulatory system all healthy and in good check! Typically including forms of walking, swimming, running and cycling, where your energy levels are fuelled by oxygen.
Shorter bursts of energy, faster paced, higher intensity in more condensed spells of activity. The energy released in anaerobic types of exercises come from the muscles, which means more power movements sustained for less time. Think weight-training (at a higher intensity), 100m sprinting, interval training. These types of exercises help strengthen bones, burn fat, build and maintain muscle mass.
Some activities, particularly many competitive sports, host a threshold of crossing over between the two, being aerobic with a longer duration of being active but met with sharp bursts of energy from the muscles: think of a cricketer sprinting to the stumps, a footballer suddenly chasing a through-ball, a 5 or 10k runner trying to increase their pace to finish with a sprint. The event goes on for a longer duration relying on the aerobic level of stamina; however, met with rapid changes in tempo over a few seconds, where the athlete applies muscular power when called to action.
Blood Glucose Impacts:
The first step of planning is knowing what type of exercise we are participating, and over what estimated duration, to then prepare for the most likely scenarios of impact.
In knowing there are two differing ‘energy systems’ and a third that applies as a threshold when these two cross over, we can strategize a blood glucose game plan to work with our diabetes during activity. In aerobic exercise, we are using stored energy from carbs, fats and proteins in combination with the oxygen we breath to generate energy to our muscles, which means we are burning this fuel and not producing it while active. In anaerobic movements, the opposite; our muscles are the fuel pushing us in these shorter moments, requiring a release of energy from within.
This means that with forms of aerobic exercise we are likely to see a decrease in blood glucose levels during activity, as the on-going movements slowly and consistently eat into our stored energy supplies; whereas with anaerobic activity, we are creating the energy in those power bursts and increasing blood glucose levels as a result of stored glucose levels being released into the bloodstream. This means that we are more likely to see varying spikes in blood glucose levels during activity.
Exercise is exercise, however, and energy is being burned whether aerobic or anaerobic. The longer the duration, the more intense the workout, the more likely that levels will be impacted further post activity. If we are seeing high spikes in blood glucose levels during anaerobic or threshold activities, there is a high chance of a U-turn occurring afterwards. This is highly associated to threshold activities, given there has been aerobic movements and a double-whammy of energy types being fuelled!
Warming up and cooling off:
Not only is there a physical importance to the body for any athlete in preparing and recovering correctly in appropriate warm-ups and cool-downs before and after activity, but there is also an essential factor to regulating blood glucose control too.
There are some core questions to ask yourself pre-exercise. This, on a diabetes perspective, is focused around what types of nutrition are in your diet and timing of food consumption before activity. Knowing nutritional insights such as the delayed released of glucose from fatty meals, to what are faster acting types of carbohydrates, can help you ‘begin as you mean to go on’ with time in range on your blood glucose levels. The more your levels are in range during activity, the higher chance you can perform to your best ability. The other key area to consider is how active your insulin is in your body? When you last bolused / how it might impact levels when starting activity. Timing of insulin and consideration of meals are essential ‘warm up’ plans in any exercise with type 1 diabetes.
Lactate is produced in muscles in anaerobic activity, which can cause muscle soreness, signalling the need for a cool down to prevent this from occurring. These high levels of lactate are moved from the muscles to the liver and converted back into glucose – being the source where those power movements were initially generated from – and with this being released into the blood, the glucose levels spike higher. A cool down that includes gentle aerobic movements and stretches reduces the amount of lactate that needs to be converted to glucose, and therefore reduces the spike.
A cool down will recompose the breathing patterns and reduce the physical stress on the body. With aerobic activity this is also beneficial, especially if having been active for a longer duration such as over 1 hour. The healthier and more cared for the body is, the better the reflection of that will be on blood glucose levels.