Whether that is true or not, I have another question: do we care
about
using fat for energy for races at which we are almost immediately
racing at lactate threshold or higher?

Another question: Do we care about optimizing fat utilization if we
are able to consume carbs during races? If we had to race without
carbs then we might want to train without carbs. But we're able to
have the same sugary drinks and snacks during a race, maybe it's okay
to consume them in training. Or even beneficial because we train the
body to absorb the carbs while racing?

There does seems to be an idea here that the use of carbs makes us more
tired from the workout. That's what's interesting. But it sure sounds
like it needs a lot more research.

Rob Bradlee