April Graff, MS, RD, LD
Hy-Vee Dietitian
Why Runners Should Pay Attention to Hemoglobin A1c
Whether you’re training for a 5K, gearing up for a half marathon, or building mileage for any endurance event, you probably track pace, heart rate, and weekly mileage. But one important metric many runners overlook is hemoglobin A1c (A1c), a marker that reflects your average blood sugar levels over the past two to three months by measuring how much glucose has attached to hemoglobin in red blood cells. Since red blood cells live about 90 days, A1c provides a long‑term picture of how your body manages glucose, your primary fuel source for training and performance.
A1c vs. Fasting Glucose: What Runners Need to Know
A fasting glucose test shows your blood sugar at a single moment after an overnight fast. It can fluctuate based on timing, stress, or even what you ate yesterday. In contrast, A1c is not affected by short‑term changes and gives a steady view of long‑term glucose patterns.
For runners, this distinction matters. A normal fasting glucose does not always mean glucose is well‑managed during long training cycles. A1c helps you understand whether your fueling, recovery, sleep, and training load are supporting healthy metabolism over time.
Who Should Get an A1c Test?
While any runner interested in optimizing health can benefit from knowing their A1c, certain individuals are at higher risk of abnormal levels. Testing is recommended for adults 45 and older or for younger adults with overweight plus at least one risk factor such as family history of diabetes, high blood pressure, inactivity, or previous gestational diabetes.
Runners may also consider screening if they experience:
- Frequent fatigue despite adequate training
- Unexplained performance plateaus
- Persistent hunger or thirst
- Frequent illness or slow recovery
These can sometimes be signs of glucose imbalance.
Because runners’ training cycles vary throughout the year, using A1c as a periodic check can help ensure your nutrition and recovery strategies are working.
Higher A1c levels mean more prolonged exposure to elevated blood sugar, which increases risk for nerve damage, kidney disease, and other complications which are issues no runner wants interfering with training.
A1c is a powerful tool for runners looking to stay healthy, fuel effectively, and maintain long‑term performance. Understanding your long‑term glucose patterns helps ensure that your training strategy supports, not hinders, your metabolic health.
Want to know your hemoglobin A1c number? Schedule your $15 screening today!
