Originally Posted by Branko D

For the OP, reading the description of his rides? Being unfit, their fat utilization is low and drops off a cliff even at light intensity. I've read a study on people with metabolic syndrome in comparison with trained cyclists and they are running off glucose at virtually any intensity. It sounds like it's his situation, and kudos to him for starting cycling because physical exercise is one of the ways for digging yourself out of that hole.


Fat oxidation in elite athletes, active healthy individuals and people with metabolic syndrome as a function of power

For those who are fit, though, it literally is a performance boost when working at near threshold power for long periods. Which does not come up in cycling so often, admittedly - alpine climbs being the exception. In long course triathlon, where working hard without drafting is the norm, eating is the fourth discipline. Sure, if you're doing an easy century on the flat, you can get by with a coffee and a croissant half way in the ride.

Eating gels on the 15 minute mark is something I do when running marathons, too. Race day isn't the day to go on a diet. All the best runners do it now, and after 80+g of carbohydrates per hour became the norm - relatively recently - the incidence of hitting the wall due to underfueling seems to have dropped off a cliff.
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