At about mile 105 of an ironman bike leg I like to slam at least 200 calories. This fills up my glycogen stores in time for T2; my brain is high functioning just when I need it most. I'm stupid enough as it is, having my petite intelligence halved by caloric depletion is just asking for trouble. I've used this strategy when riding brevets: load up just before the controls to ensure effective execution of the tasks at hand.
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Great article.