Comer o no comer

It is nonsensical to claim that fasting increases
endurance by causing muscles to burn more fat and less
glycogen so that muscles can retain their stored glycogen longer.
When you start with less glycogen, you still use it up faster and
run out of fuel earlier. You can increase your endurance by
markedly cutting back on exercise four days before your
competition and eating as much or more than usual. If the
competition lasts more than two hours, you should also eat and
drink during the event.

drmirkin.com