Why is stable glucose important for group training?
Glucose for us is like electricity for a car battery. It is stored and ready to power us for that explosive tuck jump or sustained Muay Thai!
To fuel up, we get our glucose primarily from carbohydrate-rich foods (like bread, pasta, or fruits) and sugars (from fruits, milk, and some vegetables).
Our digestive system breaks down carbohydrates into glucose through a process known as glycolysis. As it enters the bloodstream, blood sugar levels rise, and the hormone insulin, released by the pancreas, helps move glucose into our cells.
Inside our cells is where the magic happens. Through cellular respiration, glucose is broken down into ATP (adenosine triphosphate), the energy that powers our muscles, brain, and organs for those epic performances.
Extra glucose is stored in the liver and muscles. When we need energy later, maybe for a back-to-back class, our bodies convert glycogen back into glucose to give us the mental and physical energy we need. In fact, research demonstrates that glucose uptake in skeletal muscles can increase by up to 50-fold during exercise compared to resting conditions.
We often lead multiple classes per day, so keeping glucose balanced helps in muscle repair and recovery, preventing excessive fatigue from repeated exertion.
Too low (hypoglycemia) before or during a workout and we may feel shaky, weak, or lightheaded. Too high (hyperglycemia) and we may experience dehydration, increased thirst, brain fog, poor focus, muscle weakness, and reduced performance – not ideal for teaching group training!
New research reveals power of cardio
New research from Les Mills suggests the ways we eat, train and rest can bring major benefits to our glucose levels.
Over two weeks, the study saw 35 healthy adults wear a continuous glucose monitor while maintaining their typical routines. In addition, participants wore a heart rate monitor during planned exercise. They logged training sessions (total time, intensity zones, perceived exertion), daily meals (time of day, macronutrient grams), sleep (total time, subjective quality), and emotions (stress, motivation, fatigue).
The results found that short bursts of cardio help keep glucose levels stable, specifically by adhering to the following workouts:
- 2x weekly sessions of vigorous exercise, including 20 minutes within each session above 80% heart rate max, or Zone 4.
- 2x weekly sessions of longer duration moderate cardio, with a minimum of 60 minutes between 60-70% heart rate max, or Zone 2.
- A brisk walk for just 20 minutes each, above 60% heart rate max, separated by 4-6 hours when possible.
Bryce Hastings, Les Mills Head of Research, says: “Glucose is the main sugar found in our blood, acting as our body’s primary source of energy. Exercise plays a key role in maintaining glucose health because it helps regulate blood sugar naturally and improves overall metabolic health. These findings offer tangible insights into exercise and lifestyle choices that help reduce glucose variability.”
The good news
This research shows that through regular teaching, especially cardio workouts, we are already a step ahead when it comes to regulating our glucose. Maintaining stable glucose levels reduces risk of Alzheimer's, cardiovascular defects, and hypertension – Insightful knowledge we can share with our participants!
As our bodies become more adept at using oxygen, it also becomes more efficient at oxidizing glucose – crucial for exercising and muscle function, but this relationship is bidirectional. While glucose fuels our exercise, exercise, in turn, helps us regulate and balance glucose levels.
Les Mills researchers also found:
- Ideal meal macronutrient percentages equated to 50% carbohydrate, 35% protein, and 15% fat.
- A breakfast rich in protein is optimal for stabilizing glucose, with at least 0.7 ounces (about 20 grams) an ideal minimum.
This research reiterates how essential healthy carbs are, especially for active professionals.
For a steady energy release, choose a mix of complex carbohydrates, lean protein, and healthy fats 2 hours before class if possible. Greek yogurt with nuts and seeds, wholegrain toast with avocado and egg, or brown rice and grilled chicken are ideal choices.
For a last-minute energy boost, a small snack with carbs and protein is best, such as a handful of nuts and an apple, rice cakes with peanut butter, or a small protein smoothie (banana + protein powder + almond milk).
Should I buy a glucose monitor?
Once only used by diabetics, glucose monitoring is becoming more popular with fitness professionals, with the blood glucose monitoring devices market projected to reach $28.75 billion by 2030.
With all this in mind, is it worth buying one?
This research shows that, through small actions, investing in an additional wearable device isn’t strictly necessary.
Lead researcher Dr. Jinger Gottschall explains: "The key benefit of this research is that it provides manageable, actionable steps that can be incorporated into daily life to reduce glucose variability – whether or not you have access to a tracking device. We know data tracking can be overwhelming, so instead, we want to demonstrate that small adjustments – such as frequent cardio and increased protein intake – can make a significant difference."
Glucose Monitors Explained
These days, you don’t need to draw blood to check your levels – great for the squeamish!
Flash glucose monitors (FGMs) allow sugar level checks through a sensor applied under the skin, typically worn for two weeks. To get a reading, you scan the sensor with a reader device or smartphone app. FGMs are ideal for people like Instructors who don’t need continuous monitoring but are curious about a snapshot of their levels at a given time.
Read why you should be eating more and 5 hacks to fuel your workouts.
