Some studies indicate insulin sensitivity and related blood sugar issues may be more of a problem than we'd realized with physically active folks. A few things that work for me:
- Skip any snacks, energy/protein bars with sugar alcohols -- maltitol is most common, also mannitol, sorbitol, xylitol, lactitol and isomalt. While the glycemic index is lower than table sugar -- a good thing -- it tends to make some folks gassy. Not a good thing. For whatever reason I do better with plain table sugar in snacks, like Clif bars.
- Some people report digestion issues with maltodextrin, a common fuel in energy gels and other sports snacks. Doesn't cause me any problems, but check the labels on the snacks and drinks you consume and see whether omitting those for a week or so makes any difference.
- Try a readymade electrolyte mix that has at least some sugar for hydration during a workout. It aids digestion and osmolarity. I prefer DripDrop, but any recipe mixed to the World Health Organization's standard for Oral Rehydration Solution will do. Sugar free electrolyte solutions cause me to feel bloated, burpy and uncomfortable. The ORS types promote rapid rehydration and work much better.
- Timing can be crucial for consumption of carbs and sugars before a workout. If we wait too long our insulin is triggered and we don't get the full benefit of sugars and carbs as fuel. I usually eat something like a Clif bar, or oatmeal, and a banana just before a ride or run.
- If I eat candy, a donut, or drink a sugary soda, etc., I need to get back on the bike pronto to take advantage of it as fuel. If I wait too long my body tends to overproduce insulin and provoke hypoglycemia. And I usually avoid stuff like pancakes with sugar "syrup" -- something about that combo spikes my blood sugar and then I'll feel bonky in about an hour, even if I'm doing no physical activity. The worst bonk I've ever had was years ago just before a long run that included a steep hill climb run. Instead of eating my usual balanced breakfast I got the brilliant idea to load up on donuts and coffee. It might have worked if we'd started immediately. But it was about 2-3 hours later before we started and I bonked hard midway up the hill run -- literally, legs suddenly turned to jello and I flopped on the ground shaking. I'd have been better off eating eggs, etc., and carrying a few donuts with me to eat on the run.
- If you eat a meal with meat protein, animal fat, etc., you may feel sluggish and have some indigestion if you ride or work out within an hour. I usually need to wait at least 2-3 hours before my legs feel right again after a big meal with meat. Sometimes I'll have an egg -- maybe a boiled egg or small omelet.
- On rest days I try to avoid sugars and carbs. Sometimes I'll eat nothing but meat and/or eggs on rest days. No sugar, carbs, fruits, even vegetables with any sugars. No problems with digestion.