Exercise & Glucose: Why Workouts Impact Your Glucose Levels
Table of Contents
There are so many good reasons to exercise. Now doctors are even writing prescriptions for it. So it is no surprise that exercising affects even your glucose levels, but your glucose levels also impact your response to training. In this article, you will learn:
- How exercise and blood glucose are linked
- What types of exercises raise and lower your blood glucose
- How you can adjust your training to optimize your glucose levels
What is glucose?
First things first: the term blood sugar and glucose levels are synonyms. Here is why:
when you eat food containing carbohydrates, your body breaks them down into a type of sugar, called glucose. Glucose and fatty acids are your body’s main sources of energy, and after a meal, the fat is stored and the glucose is released into the blood – hence the words blood sugar or blood glucose. Your body senses that glucose has entered your bloodstream and it triggers your endocrine system (your pancreas) to release insulin that regulates the glucose by prompting your cells to absorb it for energy utilization and storage.
What can cause high or low blood glucose?
Low blood glucose levels (hypoglycemia) can occur when you don’t eat enough carbs, drink alcohol, are ill, or take certain medications.
High blood glucose levels (hyperglycemia), can happen when you ingest a large number of carbohydrate rich-foods, through lack of sleep, due to insulin insensitivity, but also due to stress, trauma, or a chronic condition. It can also affect how your body responds to exercise. Studies show that people with high glucose levels can’t reap the full health benefits of training.
Recognizing the signs of high and low glucose levels is crucial to lead a healthy life.
Both low and high glucose levels are difficult to spot and can go easily unnoticed, therefore the conditions often go untreated. A Continuous Glucose Monitoring (CGM) device can help you see, in real-time, how your diet, sleep, exercise and stress levels affect your blood glucose. Managing and controlling your glucose levels is a great way to stay healthy and prevent metabolic disorders .
Why exercising is good for regulating blood glucose levels
By now, it is a well-known fact that when it comes to your health, one of the best things you can do is exercise. So it should be no surprise that exercise effectively helps keep your glucose level steady. The muscles in your body need glucose as fuel, and when exercising your glucose demand increases because our muscles get activated. Exercise also increases our body’s insulin sensitivity, encouraging insulin to work more effectively to reduce blood glucose spikes faster.
How does exercise affect your glucose levels?
It’s important to know that different kinds of exercises affect your glucose levels differently. How they change during an exercise can depend on the following:
- Your glucose level before working out
- The type of exercise (aerobic or anaerobic)
- The length of your workout session
Intense exercises (Anaerobic) will likely spike your blood sugar as they can release the hormone adrenaline which then stimulates the liver to release glucose at a faster pace.
In contrast, steady-paced exercises with moderate intensity (Aerobics- short duration) will use fat as the main source of energy, which means that blood glucose levels will remain stable .
Once you know how your body responds to your workouts, you can prevent glucose spikes or lows. For example, if you notice a considerable spike when doing a workout, you can pay attention to what you eat before or during that exercise and your hydration. More on that further down! Let’s dive into which exercises lower or spike your glucose levels.
What are anaerobic exercises and how do they affect my blood glucose?
Anaerobic activities such as interval training, are more intense, and shorter, and will get you out of breath quickly. When you work out anaerobically, your body primarily draws on glucose, our body will use the glucose that has been stored (glycogen)in the muscle and in the liver which is why your blood glucose would spike during these exercises to meet your body’s needs . This also means that spikes resulting from high-intensity exercise are nothing to worry about. It is your body showing a response as it should. That’s what you want your body to do.
Examples of anaerobic exercises are: Interval training, sprinting, weightlifting, spinning classes, High-Intensity Interval Training (HIIT), Pilates.
What are aerobic exercises and how do they affect my blood glucose?
Aerobic exercises are when you perform an activity that will increase your heart rate at a steady pace, at a moderate to low intensity. These are exercises when you can generally speak with another person unless you’re swimming. 😉 Aerobic exercises don’t require your body to rely on glucose storage (glycogen) from the liver, this means that your body doesn’t need to produce instant energy kicks, inserted it relies on energy from fats . This means that your glucose levels generally stay the same or even go down slightly.
Examples of aerobic exercises are: Swimming, cycling, jogging, walking, rowing, zone 2 cardio, Ashtanga, Vinyasa, power and hot yoga
Exercising on an empty stomach: is fasted exercise good for my blood glucose?
Fasted exercise is when you work out on an empty stomach. You can achieve this by fasting overnight and working out first thing in the morning or before your first meal. The idea is that by the time you work out, your body is depleted of glucose stores and can access stored fat easier compared to non-fasted.. However, this practice can lead to a blood glucose dip during exercise, this dip is your body telling you you are under-fuelled (making it harder to recover). As a result, you put your body under a lot of stress, you lose fitness instead of gaining it, and you increase the risk of injuries.
How the menstrual cycle affects your workouts and glucose levels
Most women are aware that their body experiences different phases during the menstrual cycle. But, many do not realize how much these fluctuations affect their bodies. Sleep, sexual function and metabolism are all linked to the endocrine system. The endocrine system controls your menstrual cycle, and if you remember from before, the endocrine system also regulates our blood glucose levels. So it explains why the hormonal phases can impact your glucose metabolism during workouts. In other words, workouts that seemed easy and blood glucose flattening in one phase may be perceived as harder with higher glucose levels in another phase.
The hormones released during the different menstrual phases appear to affect the reliance on glucose as an energy source, as well as the glucose response to food and stress. Hello Inside has created the Hello Hormones program to show how your blood glucose levels change throughout the cycle. This allows you to optimize your exercise and glucose response.
Our tips
We’ve created some tips to optimize your glucose levels based on your exercise and vice versa
You can maximize the positive effects of a workout on your glucose levels by incorporating the following tips into your regimen:
General measures:
- Pick the exercise that suits your menstrual cycle to feel your best
- Be aware of glucose drops and refuel !(it’s best to opt for a mix of protein and carbohydrates, such as a yogurt with berries)
- If the session takes longer than 90 minutes, prepare a small snack to eat during the exercise (such as a banana, or 1-2 energy chews)
- Incorporate a fasted exercise by doing 15-20 minutes of HIIT or an aerobic exercise in the morning
- If you are going to work out in the evening, opt for a gentle exercise for better sleep and recovery. (Bonus: good sleep has a positive effect on glucose levels the next day)
To prevent your blood glucose levels from going too low:
- Move your body by taking a 15-minute walk, taking the stairs or standing up from your work desk every 20 minutes for a stretch
- Stay away from hot baths, saunas and steam rooms after a workout
- Don’t work out later than 2 hours before bedtime
To avoid spikes in blood glucose levels:
- Do gentle or moderate exercise before your first meal
- Try taking a walk after your meals: Research* shows that moving within 30 minutes of a meal will lower your blood glucose level significantly (*)
Key takeaways
Glucose works as fuel for your muscles during exercise. If you do aerobic exercises like walking or swimming, if you do anaerobic (intense) exercises, like weightlifting, your glucose levels will increase rapidly and potentially even spike.
Fasted exercises and adjusting your workout to your menstrual cycle can both boost your glucose metabolism.
It’s good to measure your blood glucose before and after you exercise. Using a CGM will make it easier and allow you to measure your glucose levels during an exercise as well. The results will help you determine what your glucose levels should be during an exercise and how to respond to them. For instance, you might want to optimize energy levels before an anaerobic exercise, or if you do a fasted exercise and notice your glucose levels are dipping, you have a previously prepared snack.
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