A thought came to me today while I was Mountain Biking in the hills near my house. I don't know if there has been research into this, or if it has been mentioned before, but it seems to make sense. So I will submit it here for your scrutiny and comments. After physical exertion, do you think that our taste sensitivity for sweetness is heightened? The reason I thought of this, is because after riding for a long time, most of which was uphill, I bit into an unripe nectarine, and it was very sweet. Sweeter than I expected it should be. I think that if you are exerting yourself, using large amounts of energy, then your body will encourage the intake of carbohydrates to replenish the expenditure. Just a thought.