Having practiced the 26+2 method for over a decade, I’ve heard a number of times over the years from yoga teachers that one should not drink cold water during class. The explanation for this was that drinking cold water actually increases core temperature because your body has to work harder to cool it down and absorb it. The cold water is even sometimes referred to as an “ice bomb” as if were an assault to the system.
The conclusions from research in exercise physiology show otherwise: drinking cold fluids during exercise do lower core body temperature. The effect of water consumption on the body during exercise is studied in various ways. In one design, the subject drinks fluid, has a tube inserted into their stomach before they exercise. The researchers then suction contents to see how fast it was absorbed or not. Studies show that cold fluid not lowers the individual’s core temp, but is also absorbed faster by the body.
Further studies show that during exercise lasting longer than one hour sodium, chloride and carbohydrates should be added to water and that, in contrast to popular beliefs, caffeine consumption does not cause water-electrolyte imbalance or reduce exercise-heat tolerance.