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Hypoglycemia in athletes




As athletes, sometimes we joke about low blood sugar. We associate it with being HANGRY (Hungry  + Angry) where we get very moody and upset until food gets inside our belly.
I'm sure you (or someone you know) have joked about a bonk that occurred while swimming, biking or running and how horrible it was when it happened but you had a funny story about how it was relieved with a massive amount of sugar/carbohydrates. 

Perhaps you have felt this experience before as the symptoms are very uncomfortable (and can be dangerous), while working out or racing. 

Hypoglycemia is an abnormally low level of glucose in your blood 
When your glucose (sugar) level is too low, your body is too low on energy to make your body function normally. 

Low blood sugar is serious and it is not a joking matter if it is occurring regularly. The occasional "bonk" is accepted when you are a high-performing athlete (and then you learn from it so you try to prevent it from happening again in a similar workout) but low blood sugar should not be something that you are trying to get comfortable with while training or racing (or in your every-day life).  

Know your warning signs when blood sugar is dropping so that you can immediately correct the issue with fast-acting sugar to raise your blood sugar. Do not reach for fat or protein as this will not raise your blood sugar once it has dropped. We use fat and protein, combined with carbohydrates, to help slow down digestion and control blood sugar levels at meals and snacks.


As an athlete, experiencing low blood sugar symptoms is not cool. It doesn't mean that you are becoming metabolically efficient, burning fat for fuel, losing weight or improving performance. It doesn't mean that you are hardcore or tough.
You are actually increasing the risk for serious health issues.

Athletes who improperly fuel/hydrate before and during workouts (and races), work out on an empty stomach, workout after going too long without eating or work out too long or intensely without adequate nutrition to support the effort are more likely to experience low blood sugar symptoms. 

As if this wasn't enough.....why should you really be concerned? 

Aside from these symptoms negatively affecting your physical performance and emotional state, hypoglycemia can affect the autonomic nervous system, which can increase the risk for overtraining syndrome. 

And even more concerning for athletes who intentionally or unintentionally struggle with fueling/hydrating properly around/during/before workouts, hypoglycemia induces a major stress on the endocrine system. When blood sugar drops (as a result of caloric restriction/inadequate fueling) before, during and after workouts, major hormones can be impaired. 

Prevention of hypoglycemia, through a healthy diet and proper sport nutrition/hydration timing, will not only help you perform better during workouts but will save the health of your thyroid, adrenals, pituitary, GI tract and other major endocrine glands. 

If you find yourself spending more than a few weeks intentionally restricting calories before and during workouts (for whatever reason), it is time to consult with a sport RD who can assist in your nutrition journey to ensure that you are meeting your metabolic needs while training. 

It's not cool to underfuel!