I've wanted to record this podcast for a LONG time. Back when I first started bike racing and training, I would go everywhere with a ginormous CamelBak containing 2L of water. Then when I transitioned off the sugary sports supplements, I noticed that I was less thirsty. Then I read Waterlogged, and suddenly it all made perfect sense. Conventional hydration wisdom is all based on faux marketing science! Or is it? This quote from Dr. Bryan Walsh: "If plasma is 93% water and you lose 0.5% of total body water, it will increase the viscosity of the blood a bit, which causes more work for the heart. How much work? I'd have to look that up, but the viscosity is considered one of the factors that determines something called Total Peripheral Resistance (along with length and diameter of arteries). Increase viscosity, increase TPR, increase the workload on the heart." I'm sure this statement is right, and yet this seemingly deleterious effect appears to have no bearing on athletic performance. My guest today is Dr. Tommy Wood, a qualified medical doctor, graduating from Oxford University in 2011. He has a previous Bachelors degree in Natural Sciences and Biochemistry from Cambridge University. After working as a junior doctor in the UK for two years, Dr. Wood is now working towards a Ph.D. in neonatal brain metabolism at the University of Oslo, Norway. Tommy writes his blog and for Breaking Muscle, and co-hosts the Eat Better with Paleo Britain podcast. Have you noticed a decreased thirst since switching to a healthy fat, lower carbohydrate approach to training? Leave a comment below and let us know!