Journalist and endurance science analyst; evidence-based takes on cadence, training psychology, physiology.

I grew believing that any amount of dehydration is too much. A simple study changed my mind: faster finishers at a marathon lost more weight than slower finishers. “Inverse relationship between percentage body weight change and finishing time in 643 forty-two-kilometre marathon runners,” Zouhal et al., BJSM 2011.

Coming from Toronto and trying do mile reps in the middle of a heat wave in Tucson, I keep this study in mind: “Deception of ambient and body core temperature improves self paced cycling in hot, humid conditions,” Castle et al.,...