in electrolytes but not sugar.
As an endurance athlete I have cycled from Toronto to London Ontario (240km) on the back roads with nothing more
than 3-4litres of electrolyte drink rich in sodium, potassium, magnesium, calcium and chloride. These allow the muscles to
continue to contract with force and not become too saturated with plain water. Too much plain water leads to HYPONUTRIMIA.
Too much water not enough electrolytes and muscles slow their contractions. A drink rich in electrolytes also allows the body to access fat for fuel and not depend on carbohydrates / sugars.
The lipolytic pathway is interesting and far more detailed than outlined here. If you have further questions feel free to comment. Recreational runners would do themselves a great service to stop feeding on starch and start eating for high nutrient, normal portion sizes and let the body figure out where to get its’ fuel from.
Like your mother always said, “don’t swim with a full belly.” Well don’t exercise with a full belly either. The only competitors loading up at the pasta dinner are the recreational runners. The elites eat a balanced meal of protein, fat and some starch based on their lean body mass only.