Sugar "Highs" and "Lows"
Sugar "highs" and "lows" can easily occur in overfat, underfit people. Athletes, however, can metabolize sugar without problems. That's because exercise enhances the transport of sugar from your blood into your muscles with far less insulin than needed by the body of an unfit person. The unfit body contributes to the rise in blood sugar that triggers the need for excess insulin and leads to the "crash."
The most common reason for "sugar crashes" (hypoglycemia) among athletes relates to running out of fuel. The shakiness and sweats are because the athlete did not eat enough carbs to maintain normal blood glucose levels and the brain is now demanding sugar. One marathoner thought the 100-calorie gel he took at mile 16 caused him to "crash." More likely, he needed 200 to 300 calories to meet his energy needs, not just 100 calories.
You Are An Experiment of One
If you have intestinal distress relating to wheat, gels, onions, milk or any fruits, veggies and grains, your best bet is to figure out how much (if any) you can tolerate. The dose might be the poison.
If you need to eliminate wheat due to celiac disease or gluten intolerance, you might have trouble getting enough carbs to fuel your muscles. That is, you'd need to eat three cups of blueberries to replace one bagel. Not only is that expensive, but also puts you at high risk for undesired pit stops.
Consulting with a registered dietitian (RD) can be a smart idea. The referral network at SCANdpg.org can help you find a local sports RD who can address your food concerns and take the confusion out of carbohydrates.
1. Lowndes, J, S Sinnett, S Pardo, V Nguyen, K Melanson, Z Yu, B Lowther, J Rippe. The effect of normally consumed amounts of sucrose or high fructose corn syrup on lipid profiles, body composition and related parameters in overweight/obese subjects. Nutrients 2014. 17; 6(3):1128-44
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