Hydration Consideration for Female Ultrarunners with Nidia Rodriguez-Sanchez, PhD #208
Episode overview:
Nidia Rodriguez-Sanchez, PhD has spent her career in the field of sports nutrition and physiology. She earned her BSc in Dietetics / Clinical Nutrition and later pursued postgraduate studies in Anthropometry and Nutrition applied to Sports, which gave her a better understanding of the unique nutritional needs of athletes and physically active individuals.
Dr Rodriguez-Sanchez has worked as a sports dietitian for a Mexican professional football team and as a nutrition advisor for the Gatorade Sports Science Institute Mexico. She also holds an IOC Diploma in Sports Nutrition and she is an ISAK Level 3 Instructor.
Dr Rodriguez-Sanchez holds a PhD in Hydration Physiology and has completed post-doctoral research in the field.
Currently, she is a Physiology and Nutrition Lecturer at the University of Stirling, where she also serves as the MSc Sport Nutrition Programme Director.
In addition, Nidia is a Fellow of the Higher Education Academy (FHEA), a Graduate member of the Sport and Exercise Nutrition Register (SENr), and a member of the Physiological Society (PhySoc).
Episode highlights:
(17:53) Theory on hormone cycles and hydration: estrogen and progesterone can impact nutrition needs, performance, brain function, investigating fluid and electrolyte balance
(25:27) Practical considerations for females: no meaningful differences in hydration for female athletes versus males or across different phases of their cycle, no performance differences, avoiding overhydration, cross-cycle variations in core temperature are insignificant
(36:23) Sweat testing: Precision Hydration sweat testing at CTS, sweat testing protocol, menstrual cycle phase does not impact results
Our conversation:
(0:00) Introduction: the sparse and confusing research landscape on female athletes, introducing Nidia, do females have specific hydration requirements,
(1:56) Nidia’s academic background: working as a clinical dietician in Mexico City, transitioning to nutrition for sport, working with the National Performance Center, IOC diploma in sports nutrition, moving to Scotland and PhD work in hydration
(5:47) Nidia’s sport background: being a Spinning Instructor, getting the running bug, how experience as a runner helps with prescribing workouts for athletes
(8:16) Nidia’s new paper: open access, link in the show notes, reasons for writing a review article, 30% of sports studies include females, special issue of review articles on female athletes, organizing the special issue
(12:06) Research on female athletes: recently gaining traction, questions about how hormone cycles affect physiological responses, lack of research on women
(13:31) The changing landscape on female athletes: women not being allowed to run the marathon, Kathrine Switzer, attitude toward sex differences, individualization
(16:19) Considering female-specific interventions: reasons, mechanistic plausibility, we are all the same organism, sex and individual differences
(17:53) Theory on hormone cycles and hydration: estrogen and progesterone can impact nutrition needs, performance, brain function, investigating fluid and electrolyte balance
(19:44) Research based on the “perfect” menstrual cycle: not realistic, research challenges, controlling variables in women takes much longer to test at the same point in the cycle
(21:10) Describing the menstrual cycle: follicular and luteal phase, menses is day 0, ovulation at day 14 in the “perfect” 28 day cycle, fluctuations in estrogen and progesterone
(22:40) The menstrual cycle and hydration: changes in body core temperature, reduced osmotic threshold for thirst, potential risk of hyponatremia, focus on changes in core body temperature and thirst
(25:27) Practical considerations for females: no meaningful differences in hydration for female athletes versus males or across different phases of their cycle, no performance differences, avoiding overhydration, cross-cycle variations in core temperature are insignificant
(30:00) Hydration across the cycle: no reason to change hydration strategies, vary hydration strategies based on environmental changes
(31:27) Core temperature: the magnitude of core temperature change due to exercise vastly outweighs changes due to hormones, ~0.5 degree difference
(33:12) Electrolyte considerations: hydration means water and electrolytes, sodium concentrations are slightly lower in women, 45 vs 40mmol/L, challenges with matching body size and absolute exercise intensity in research
(36:23) Sweat testing: Precision Hydration sweat testing at CTS, sweat testing protocol, menstrual cycle phase does not impact results
(39:40) Generalized electrolyte recommendations: examples, even a 10% change might not be significant
(41:11) Post-exercise rehydration: estrogen changes thirst perception, mechanistic details, progesterone and aldosterone, kidney function, menstrual cycle does not affect post-exercise rehydration
(44:38) Research on female athletes: the call for more research, research thus far has revealed no practical differences between males and females
(46:42) Needed future research: contraception and contraceptive methods, amenorrhea
(49:39) Assessing hydration needs: a big performance determinant, testing personalized sweat rate
(51:33) Individualization of hydration strategies: practical considerations, practice during training
(54:28) Nothing new on race day: this includes GI, mental training, nutrition and hydration strategies, and ingestion rate
(56:49) Adaptability: Nidia’s example of getting lost before the Chicago marathon, everyone has a plan until they get punched in the mouth
(57:48) Wrap-up: where to find Nidia
(58:58) Outro: giving thanks, hormonal considerations for female athletes are outweighed and encompassed by individualization in training, check out the research, feel free to debate, share the KoopCast
Additional resources:
Fluid and electrolyte balance considerations for female athletes
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