Discussion: sugar

will always boost you, even if you are well adapted to fat./
Burning sugar requires less oxygen, per unit of energy generated, than fat.
There's the brain element too, brains run on sugar

It sort of makes sense that if fat adapted/been on a low sugar diet for an extended period of time, putting a bit of sugar is like nitrous and will probably have a greater effect - effectively train low sugar, race high(er) sugar

Same as the caffeine effect - or the pre-marathon carbohydrate bleed out.

@Nick, not really,
It has a more noticeable effect, but not a greater absolute effect.
Think about it, that's not how the body works, its not why we train.
We train the body to become more efficient and have greater capacity to perform a task. Not using sugar isn't going to make us better at using sugar.

@Jon, also not really.
Caffeine, we become adapted to its regular presence, so if we don't have caffeine and then take some it will have a greater absolute effect on the body.

Murray, is the low sugar diet off the back of Tim Noakes on the radio ?

All very interesting. Nope, nothing to do with Tim Noakes, just around trying to eat a bit cleaner - avoiding sugar, sweetners and processed foods where possible.