I get hypoglycemia during exercise, fasting or not, brain fog, fatigue. This has been happening daily for a month. Prior I had been exercising an hour a day five days a week, no issue. Currently still aiming for five but symptoms will start out on my bike or on the treadmill. I had a gastric bypass 11 years back. I rarely get the hypoglycemia episode when I would eat sugar. History of insulin resistance. Glucose is always under 100. Insulin was 9 six months back. It was 6 two weeks ago, glucose was 88. Ferritin 15, d-20. Currently, I am having Neurontin 800 four times a day, Vyvanse 50 once daily.