I'm struggling with the maths,
if you do a long ride at race pace and your HRM say you've torched 1600cals, thats 400g of carbs....
brown rice has 23g of carbs/100g mass.
you'd need to eat and extra 1.7kg of brown rice that day!!!!
if you do a quick run and your HRM say you've burnt 400cals, thats 100g of carbs....
WH pasta has 46.9g of carbs/100g mass.
you'd need to eat an additional 213g(uncoooked - more when cooked) of WH pasta just for that short run?
that seems a lot - maybe that's where I'm going wrong though.