Some endurance athletes can have blood sugar levels that look like they're prediabetic or diabetic, even though they're actually healthy, because their bodies use up glucose so fast during training.

Doing light, steady exercise like walking or slow cycling doesn’t seem to change blood sugar levels much in healthy adults who don’t usually exercise.

Doing really intense endurance workouts might raise your blood sugar levels and make it look like you have diabetes, even if your body is actually super healthy.

About 30% of middle-aged competitive athletes eating a typical high-carb, low-fat diet have blood sugar levels that are higher than normal but not quite diabetic. When these athletes switch to a low-carb, high-fat diet, their blood sugar returns to normal levels.

Adults with type 2 diabetes who did aerobic exercise had about 12 more mg/dL lower fasting blood sugar than those who didn't exercise, after 12 weeks.

Cyclists who eat a keto diet for 5 days have lower blood sugar after exercise than when they eat their normal diet, which might make them perform worse because their body isn’t managing sugar as well.