Ever stopped for a food and rest break during your run/cycle and found yourself more tired and weak when you started exercising again than before you stopped?
If so it is likely that you experienced a phenomenon called “Reactive Hypoglycaemia”.
Reactive meaning in reaction to….hypo meaning low….glycaemia meaning sugar levels. So – low sugar levels in reaction to eating/drinking. Symptoms include tiredness, weakness, poor concentration, dizziness, trembling, anxiety and palpitations.
Whenever we consume sugar or carbohydrates this causes a rise in our level of circulating blood glucose and this is perfectly normal.
High circulating glucose levels over an extended timeframe when we are at rest however, are harmful, therefore our pancreas produces insulin to help store away this glucose in our muscles and liver. This is one of the main functions of insulin….it is a storage hormone….it opens the door for glucose to enter storage sites in our body.
When we are exercising at moderate to high intensity (not resting or gently walking) and we consume food/drink containing carbohydrate, our blood glucose rises in the normal way. The difference when we are exercising versus resting is that our body needs this glucose to make energy, and so our glucose storage mechanism via insulin is turned off to enable us to burn the glucose in our blood. Blood glucose levels come down naturally as this happens.
The issue here arises when we stop exercising at a rest stop to take in food/drink that contains carbohydrates/sugar and we wait around too long before we start moving again. When we stop exercising, our glucose storage system via insulin “comes back online”, meaning that the sugar that we consume during that rest stop will be acted on by insulin shortly after it enters the bloodstream.
Having initially risen after eating/drinking our blood sugar levels then quickly fall as this glucose is stored away, thus causing us to experience the symptoms associated with low blood sugar (tiredness, weakness, poor concentration, dizziness, trembling, anxiety and palpitations) shortly after getting moving again.
The best strategy to avoid this while out exercising is to not hang around after taking in sugar/carbohydrate. Say if you plan to stop for 30 minutes, then only consume the food/sugary drink in the 10-15 minutes maximum before you get moving again.
If you are on a bike you might even bring the food/drink with you to consume when you are moving again. If you consume the food/sugary drink at the start of your break and then rest for 20+ minutes then you are exposing yourself to the risk of a blood sugar crash and the above symptoms.
If this happens then the only solution is more sugar. Being on this sugar rollercoaster regularly is not good for our health.
We can be efficient in the way we consume sugar/carbs when we understand better the effect they have on our body.
Our ability to regulate our blood sugar levels in day to day life are influenced by many factors including stress, the condition of our gut and the possible presence of nutrient deficiencies. The energy and mood highs and lows we can sometimes experience throughout the day can be a sign that our blood sugar is poorly regulated.
The good news is that there are things we can do to help ourselves with this, and often the foundational step is to include more protein with each and every meal we eat. While it might not be workable to consume protein when we are exercising, making improvements to our day-to-day diet pattern will have positive impacts on our exercise performance over the medium to longer term.
I hope that you found this article useful. If you have any questions or comments or would like personalised support on any of the topics mentioned above, please feel free to get in touch for a free introductory call.
Paul Kinsella,
Registered Nutritional Therapist
BANT Registered Nutritionist
Copyright, 2023.
www.optimal-health.ie
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