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Why You Experience Blood Glucose Lows When Training for a New Sport


Did you know that if you are untrained for an activity you will require approximately 25% more glucose than when you are trained?

Training builds glycogen stores which tend to reduce glucose fluctuations (decrease lows with less post prandial rise). Once insulin is adjusted, fit people therefore tend to have more stable blood glucose levels.

This phenomenon is why I used to love the first two weeks of volleyball season…low blood sugar = candy! The use of these new volleyball muscle groups typically required a higher carb intake and/or a greater reduction in insulin levels. Once my muscles were trained, however, my blood sugars would begin to stabilize again. No more candy for me!

This can obviously apply to someone inactive, who is beginning to exercise, but interestingly it can also apply to an active person who is simply training in a new sport. For instance, someone who is a fit and avid runner will require a higher carb replacement for a long bike ride than they may for a long run, and vise versa. Simply put, the less trained a person is in a particular exercise, the more they will need to lower their insulin doses to prevent lows.

Have any of you noticed this when trying a new exercise?