Originally Posted by kewlrunningz
Well it does take more energy to heat up water. Your ambient temp will drop slightly and your body will have to compensate. This burns so few calories it wouldn't matter. So yes cold water causes you to spend more energy. No it does not make you slower. Yes it helps to drink cooler liquids. Pro's outway cons.
Uh, if you are working hard enough to break a sweat, then you're generating enough heat that your body is actually trying to get RID of the heat. In fact sweating is a cooling mechanism (evaporation is an endothermic process). And sweating costs energy, believe it or not. This is why your heart rate is significantly higher in the heat at equal perceieved effort as in the cold... because your body is spending energy pumping blood to your sweat glands and pumping that water out of your pores. If you are sitting on the couch eating a gallon of ice cream watching the boob tube, then yes, you'll have to actually burn some calories to generate the heat. But pumping away at the pedals, you're generating more than enough heat to keep your body warm. That glass of ice cold water is a relief, not a burden.