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The Real Science of Sport Podcast
The Real Science Of Hydration During Exercise
Dr Tamara Hew-Butler is the Queen of Hyponatremia (@hyponaqueen on X). What's hyponatremia, you may be wondering? It is a condition that is far more dangerous than dehydration, and which can develop when we drink too much fluid during exercise, with potentially lethal and often tragic consequences. We have been conditioned to fear the health and performance risks of dehydration during exercise, to believe that we cannot afford to lose fluid, and that by the time we are thirsty, it's too late. But Hew Butler, a world authority on fluid requirements during exercise, is here to set the record straight, to explain how exquisitely our bodies regulate our sodium and fluid levels, and why we can and should trust our physiology instead of the marketing messages of sports drinks and water companies. This is an episode that will challenge beliefs, and set the record straight on exercise hydration.
Show notes
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Links to articles on the subject matter of the podcast
- Tami is lead author on a series of consensus statements on Exercise Associated Hyponatremia. This is the most recent version of that consensus
- The Men's Health article mentioned on the show, discussing overhydration and quoting Tami
- A review article by Tami, published in 2017, with details on the physiology, treatment and prevention of hyponatremia
- A 2022 paper by Tami, on the Physiology, Psychology and pathophysiology of overhydration
- A study Tami was involved in looking at soldiers doing a 40km march, showing that drinking to thirst avoided the dangers of both hyponatremia and dehydration
- In the show, we spoke about research we did at the Comrades Ultramarathon. Here is one of the papers from those studies in the medical tent
- Two papers on what typically happens during ultra-endurance exercise, first in Ironman athletes, by Sharwood et al
- A second paper describing over 2000 endurance athletes and the changes in body weight, sodium levels and hydration status
- The first case series of hyponatremic athlete in the Comrades, going all the way back to the 1980s
- Tami's X handle: @hyponaqueen
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Stop Watching the Ball: Michael Cox Unlocks the Fascinating Hidden Sides of Football
01:19:18|Love the show? Becoming a Supporter unlocks a weekly bonus Applied episode, ad-free listening, and our Discourse forum where you can engage with us directly. All for the price of a coffee, once a month, so become a member now!Show notesMost of us watch football and follow the ball. Football journalist Michael Cox watches the spaces, the shapes and the patterns that few others understand. As we build towards the FIFA World Cup Quarter-finals, Ross and Gareth sit down with one of the sharpest tactical analysts in football writing, and perhaps the best at explaining it. Whatever your level of interest, you'll come away seeing the game completely differently.Cox runs the rule over all the major teams and players at this year's World Cup, dissecting and explaining their strengths, their weaknesses, and what will decide each tie. Along the way he unpacks the tactical questions casual fans never quite get answered: how France's individual brilliance differs from Spain's possession and shape, why Messi and Haaland barely run and how whole systems are built to let them save their bursts, the shift from man-marking to zonal defending, the risk-and-reward of a full-back charging forward the instant his team loses the ball, what "shape" even means, and why he's the most data-sceptical "data nerd" you'll meet.Then the harder ground. What's holding back the development of African, South American and Asian football, and is the European academy machine now so dominant that its cast-offs are better than the players other nations produce at home? As for VAR, he explains what he'd change, why he thinks it's stripped the joy from celebrating a goal, and how one fan-owned league in Europe refuses to touch it.Whether you live for football, or only watch the biggest games, this wide-ranging interview will change how you watch football.Today's Guest: Michael CoxMichael Cox founded the influential tactics site Zonal Marking in 2010 and is now a regular contributor to The Athletic. He's the author of two books — The Mixer, on the history of Premier League tactics, and Zonal Marking: The Making of Modern European Football.He is a keen supporter of @KingstonianFC. You can follow him on X: @Zonal_Marking and BlueSky: https://bsky.app/profile/zonal-marking.bsky.socialLinksMichael's bio page with The New York Times, containing links to all his articles (paywalled articles, unfortunately - selected articles to read for Members on Discourse)Michael's first book, The MixerZonal Marking: The Making of Modern European Football, his second book
England Survive Altitude and Mexico / The Doctor's Dilemma in Elite Sport - When Is Enough? / How Women Out "Pace" Men in Marathons
01:18:32|Not a Supporter yet? For the price of a coffee a month you get ad-free shows, a weekly Applied Science show, access to our Discourse and Discord communities, and participation in our listener research studies — join the Real Science of Sport here.Show notesIn this week's Spotlight, Ross and Gareth take on the news:(00:02:00) Football World Cup: England survived altitude and Mexico, and Ross's numbers explain how — less total running, fewer sprints, the game deliberately slowed down. It's a collective pacing strategy dictated by physiology, not just tactics. Plus VAR is amplifying the chaos rather than ending it (Argentina's late smash-and-grab over Egypt, a sensor in the ball denying Croatia), and six African teams knocked out in the dying minutes.(00:28:00) Tour de France: our first read on the opening stages, and why the new team time trial format, where the rider's individual time counted, added genuine tactical intrigue.(00:31:00) The story that troubled us most: riders starting stages very sick in 40°C heat. After De Lie and Uijtdebroeks pushed on while ill, we discuss the incentives in elite high performance sport that put team doctors is unenviable and often compromised positions, and whether, as with concussion in rugby, sports governing bodies should step in to alleviate the conflicts faced by medics?(00:39:00) The science of pre-cooling: why INEOS sat in a row with their forearms in cold water. Ross explains the AVAs, the skin's heat-dumping shortcut, and why the water mustn't be too cold or you shut the whole thing down.(00:53:00) Record watch: Josh Kerr's unusual race-free build-up and his 3:42 fixation, Keely Hodgkinson's choppy season, and Faith Kipyegon's first 1500m/mile defeat in five years.(00:58:00) A cracking paper spotted by listener Steve O'Hale: 870,000 Berlin finishers show men are twice as likely to hit the wall as women. And, counter-intuitively, the faster the men, the more likely they are to blow up, relative to women. Ego or physiology? We dig in.(01:08:00) And finally: a 10-year-old tennis prodigy, homeschooled and training seven days a week. A feel-good story, or early specialisation and survivorship bias dressed up as one? Plus Wimbledon heads for it's 9th straight first time winner on the women's side.LinksOur football World Cup thread, for Supporters Club members, containing all the Mexico-England analysis and more discussion on the tournamentMovistar under fire as Uijtdebroeks races on while illThe Stanford Glove - researchers thought they'd found a way to 'hack' cooling with a Zoolander like vacuum gloveBBC article on Josh Kerr's 3:42 target preparationsKerr on the importance of psychology in his preparationThe Nature paper on men vs women pacing strategies in the marathon
Inside the World of F1 Racing: An Engineer's Perspective
01:37:52|Love the show? Become a Member and get a weekly bonus episode, ad-free listening, our VIP community, and a real say in what we discuss!Show notesFormula 1 is one sport we've never properly tackled, so who better to guide us through it than a man who spent 25 years on the inside? Dom Riefstahl is a mechanical engineer who went straight from graduation into BMW's F1 programme, later moving to the Sauber F1 team and then to the Mercedes AMG Petronas F1 outfit, where he worked with seven-time world champion Lewis Hamilton. Riefstahl now keeps his eye on the ball as an F1 pundit for Luxembourg public broadcaster RTL.In this interview, Riefstahl takes us inside the world's most sophisticated sport, and, in particular, the fascinating triangle among driver, engineer, and car. He explains how a driver's feel for the car is translated into action by engineers armed with 400 sensors and 40 000 channels of data, why the great drivers are the ones who can tell whether a problem comes from their own driving or from the car itself, and how a top driver sometimes feels things the technology can't yet measure. Along the way, we learn what it costs to develop a driver from karting to an F1 seat, why reaction time can quietly end a career, why the truly great champions are hypersensitive about everything from tyre temperatures to wafts of garlic, and why the driver you're most likely to have a pint with will probably never be world champion.
BONUS SHORT: Altitude and the Mexico Problem. The Science Behind England's Sunday Showdown
20:33|Become a member of The Real Science of Sport Podcast, and join our community, get ad-free shows, exclusive episodes, and a world of discussion on topics just like this! Click here for all the Member Benefits.Show notesA bonus hype show ahead of Sunday's World Cup round of 16 between Mexico and England, where altitude has become the story everyone is talking about. Sparked by Thomas Tuchel's lament over a FIFA rule and the team's potential "smash and grab" altitude adaptation theory, Ross explains why the idea of sneaking in and out before altitude bites has no supporting evidence at all. You only ever get better from the moment you arrive, and so FIFA compelling England to travel earlier is quietly helping them!From there, Ross unpacks the physiology: lower air pressure, less oxygen reaching the muscles, a compromised VO2 max ceiling, and everything performed at a higher relative intensity. Drawing on repeated-sprint studies and FIFA match data from Mexico's altitude venues, he builds and tests a hypothesis, that visiting teams run less at high speed and make fewer sprints, with a dose-dependent decline as altitude rises. The small, admittedly limited study illustrates how Mexico's altitude adapted advantage might manifest in sprint and high speed running differences from the start, getting progressively larger. Ross closes on what England can realistically do tactically to respect the physiology.LinksThe Guardian article on England's foiled smash-and-grab paradigm, fortunately for them!This is the study I've seen cited in support of the late-arrival theory, even though its conclusion actually refutes the advantage!A study showing that you only get better, over 6h, 17h and then 48h, so get in as soon as you canAnother one, this time over longer time frames, looking at how we improve with more time at altitudeBrosnan study on repeat sprint interactions with altitude and rest period
Durability - Trialled, Tested and Explained / Werro Edges Closer to the World Record / The World Cup's Extra-Time Problem / TDF and Heat Fears
01:11:04|Become a member of the Real Science of Sport! You get ad-free shows, a member exclusive show every week, access to our communities and post-pod discussions, plus the chance to participate in our unique research studies. There's more too - click here to see all the benefits, and a small monthly pledge is all it takes!Oh, and play our Tour de France Fantasy League - we have one special rule - no Pogacar allowed! It's league number 90980, Science of Sport, and the password is ISMPJShow notesThis week's Spotlight checks in on our global durability study, takes another lap of the World Cup, visits the Diamond League in Paris, previews the Tour de France and its heat challenge, and ends with saltwater crocodiles.In this show:Our listener durability study is underway (members only!), and Ross and Gareth compare notes after completing the first session, a brutal five minute TT plus 20 minute FTP protocol. Ross explains why you have to drain the anaerobic battery before the 20 minute test, why pacing a time trial on your own is harder than you think, and why the biggest limitation in the study might not be physiologyThe World Cup is into the knockout rounds and listener Robert Ridley has done the maths on whether teams that go to extra time are at a disadvantage in the next game. The answer might be yes, about 1.5x more likely to lose if they play a team who hadn't had ET the game before, but we discover the confounding factor that complicates that findingA proposal resurfaced on Discourse and social media this week for a structural fix to extra time football, one that involves running the penalty shootout before the 30 minutes rather than after it. Ross explains where the idea came from, what the data says about goals in extra time, and why football fans on social media were not especially receptiveMoving onto athletics, Audrey Werro ran 1:53.80 in Paris, another personal best that edges her closer to the oldest WR in the sport, but we explain why the record attempt fell short, and what her split data tells you about the mindset that Werro and Hodgkinson need to bring to their races to really threaten the WR. Femke Bol is now in the picture too, and her progression curve is worth paying close attention toMarco Arop ran 1:41.84 in the men's 800 and declared he is going for Rudisha's world record. We discuss whether the men's record might actually fall before the women'sThe Tour de France starts this weekend in temperatures forecast to exceed 40 degrees by the end of the first week. We discuss a study documenting rising temperatures at the race over the decades, why the UCI's heat protocols are again under scrutiny, and what the Tour's own route designer says about how he is now choosing routes specifically for shadeUCI president Lappartient has floated the idea of reducing Tour de France team sizes from eight to six riders and introducing budget caps. The internet reacted badly, including a memorable contribution from Johan Bruyneel. We make the case that smaller teams might actually create more dynamic racing and more opportunities for smaller squads, with the acceptance that there are economic factors in play. But we wonder, why criticism is often so loud, but so empty?And finally, an IOC official has just discovered that the rowing venue for Brisbane 2032 is in a river that is also home to saltwater crocodiles. His suggested solution was a fence. We hope the rowers don't catch a croc...
13. The Creatine Episode
01:48:42||Season 8, Ep. 13From muscle growth to a treatment for Alzheimers, creatine has been touted as the 'King of Supplements'. But what does the science say about one of the most researched products in sport? Enter Dr Eric S. Rawson, Chair and Professor of Health, Nutrition, and Exercise Science at Messiah University in Mechanicsburg, Pennsylvania, who has spent two decades studying the effects of creatine on the brain and muscle. In this in-depth interview, Rawson breaks down the long history of creatine research, how it works, who it works best for, and the latest research into its cognitive benefits. Rawson has been an active member of the American College of Sports Medicine (ACSM) since 1996, has served on the ACSM Board of Trustees and is a Fellow of the ACSM (FACSM). Dr Rawson has delivered more than 180 professional presentations, is co-editor of the text Nutrition for Elite Athletes, co-author of Nutrition for Health Fitness and Sport, and has authored/co-authored numerous articles and book chapters. His research has been funded by the National Institutes of Health and various foundations.SHOW NOTESRawson was involved in the IOC consensus papers on supplementation. Here is the latest of these, including a section on creatineA systematic review and meta-analysis on creatine use, combined with resistance trainingA review on safety concerns over creatineThe 13500 person review on the side effects of creatine use with long-term supplementationWidely hailed as the original creatine paper, by Harris et al, this showed that supplementation with creatine could increase muscle stores significantlyStudies showing that muscular performance was enhanced by creatine supplementationA recent scoping review explores the available evidence on the possible protective effect of creatine in concussion managementDisclosures from Dr Eric Rawson:• Been taking creatine since 1992• Have published/presented a fair bit about creatine and other supplements. You can see Eric’s research profile here• Been fortunate to receive funding from NIH, various foundations, universities, and companies• Current research funding: none• Have received speaking honoraria for lectures that included creatine• On SAB of Alzchem (studied creatine supplements for 20+ years first).
12. Re-Release: The Art and Science of the Perfect Football Penalty
01:17:55||Season 8, Ep. 12British football journalist Ben Lyttleton literally wrote the book on football penalties. As the author of 'Twelve Yards: The Art and Psychology of the Perfect Penalty' and 'Edge: What Business Can Learn From Football', Lyttleton is arguably the world's leading authority on the subject. His encyclopedia-like and passionate knowledge of both the game of football and the controversial penalty, make this one of the most entertaining podcasts we have done yet. This podcast was first published in August, 2022, but is sure to be relevant to the final weeks of this year's edition as we head into the knockout stages.SHOW NOTES: The Twitter handle of our guest Ben Lyttleton: @benlyt, or https://twitter.com/benlytBen’s website, Twelve Yards: https://twelveyards.substack.com/Article on where to aim, high or low: https://twelveyards.substack.com/p/high-or-low-where-to-aimFascinating article with video on Neymar’s now illegal stop-start method, and his adjustments: https://twelveyards.substack.com/p/what-neymar-did-nextThe curse of the superstar - why stars miss more penalties: https://twelveyards.substack.com/p/mbappe-culture-and-the-superstarThe study on English players’ failure in shootouts that kicked off this interview: https://pubmed.ncbi.nlm.nih.gov/19058088/Emotional contagion paper, and how player celebrations affect shootout results: https://pubmed.ncbi.nlm.nih.gov/20544488/The most famous penalty miss ever? https://www.youtube.com/watch?v=g8WtxgFvvj0The original panenka: https://www.youtube.com/watch?v=VxXWIZULgyw
A Doping Refusal and Four Year Ban That Divided Tennis / Hodgkinson's Hamstring Scare / World Cup Science
01:03:20|Become part of the Science of Sport Community, and take part in our global durability trial, plus get our free show, ad-free listening, and our world class forums! A small monthly donation is all it takes!This week's Spotlight focuses on the doping case of Marketa Vondrousova's four year ban for refusing to provide a sample during an out of competition test in 2025. We also return to the USA for some Football World Cup insights, cover some injury science with implications for Keely Hodgkinson's season, and issue a call to arms for members ahead of our durability experiment. Here's what's on the show today:A leg-breaking tackle in the Canada versus Qatar game sparked a debate among our listeners on Discourse that cuts to the heart of how sport punishes dangerous play. Should the sanction reflect what the player did, or what happened as a result? Ross draws on his rugby background to explain why outcome-based punishment is more common and more defensible than it first appears, and why intent is almost impossible to use as a standardTravel demands at the World Cup are discussed by a listener in this article - we ask whether this could be decisive to the outcome, which takes us on a journey into travel load and its implications for performanceThe momentum graphics appearing on screen during World Cup broadcasts continue to prompt discussion among our listeners. We explore how they actually work, why they might be interesting to fans but are almost certainly meaningless to coaches, and what question you would need to answer before you could trust them at all?Our main feature is former Wimbledon champion Marketa Vondrousova, now banned for four years for refusing a doping test. We explain why the anti-doping system has to treat a refusal as the equivalent of a positive test, why her own social media post on the night made things worse for her, and why comparing her ban to the Sinner and Swiatek cases misses the point entirelyKeely Hodgkinson withdrew from the 400 metres at the UK Athletics Championships in tears after experiencing "hamstring tightness" before the race. We explore why, even if this turns out to be nothing, the pattern of recurring hamstring tightness is worth paying close attention to, and shares the sobering statistics on hamstring re-injury rates and risk factors that make this more than just a precautionary withdrawalWorld Rugby has permanently approved a lower tackle height for community rugby, but with a catch: different unions can choose between the waist and the sternum as their legal limit. We discuss why that flexibility exists, what it means in practice, and what would have to be agreed before any change could come to the elite gameA cyclist suffered a concussion during the Tour de Suisse and continued racing for several more stages. Gareth's initial reaction is that it's another policy failure by the UCI, but we discuss it and discover a number of scenarios that would explain how it happened without any fault from the UCIAnd finally, a call to action for members. Our Applied show this Friday will cover durability, and we are turning it into a live global experiment. Over the coming weeks we will be asking supporters to complete a set of time trials on the bike, and we will use that data to build your power duration curve, work out your W prime, and calculate your durability index. All the details will be on Discourse and Discord for membersOh, and why is Messi so comparatively poor at penalties? Our previous guest Ben Lyttleton shares a piece he wrote on why the best ever is average from the spot!
World Cup Water Breaks / What Will It Take to Break the 800m WR? / College Sprinting Goes Wild / Does Remco Have the Watts to Match Pogacar?
01:11:19|Become a Supporter, and get ad free podcasts, your exclusive Applied science show every week, and access to our listener community, with all its insights and opinionsShow notesThe Football World Cup is underway, and hydration breaks have been one of the early storylines. We discuss whether they are a genuine player welfare initiative, or a (very) thinly veiled advertising slot, whether there will ever be evidence they are changing the dynamics of matches, the concept of momentum (real or imagined?), and why a combination of heat and end of season fatigue might explain some lacklustre performances so far?Teenage phenoms had mixed fortunes in the Diamond League last week. Cooper Lutkenhaus flew (literally, across the line) to another win, this time over the Olympic champion in the 800m, while Gout Gout stuttered in his Diamond League 200m debut. Gout partly bounced back in Ostrava, but he highlights again the challenge of unrealistic expectations. Speaking of Ostrava, Werro was fast again, while Bol impressed in her debut, but is, for now, a generation and 3 seconds behind the big two. Can she improve enough to legitimately challenge them, and what will it take for Werro and Hodgkinson to get closer to that WR, from a pacing and race strategy perspective? We discuss.A genuinely wild NCAA Championships in Eugene produced what might be the best single meeting of sprint performances in history, headlined by a shock 110m hurdles world record from 20 year old Ja'Kobe Tharp. We work through the collegiate records that fell in the 400, 200 and 100, and ask when next these athletes will run as fast as they did last week?Adaejah Hodge was one outstanding performer, clocking the 5th fastest time ever over 100m, a 10.63s. Her backstory asks some uncomfortable questions about a secret doping ban, a case resolution agreement, and a high school coach who was the target of the investigation. We unpack the details and ask whether the sport is getting the trade-offs right?Letrozole, fertility treatment, and an unusually candid announcement from double world champion Gudaf Tsegay explain why her four month doping suspension is one of the more sympathetic cases we have coveredRemco Evenepoel's threshold power numbers were revealed in his latest YouTube video, and we discuss what 425 watts for an hour actually means heading into the Tour de France, why durability rather than fresh power might decide the race, and why the one hour threshold power may be less of an issue for the Belgian than his 20 to 40 min climb powerAnd finally, some good news from the Discourse community: Supporter club member Sophie coached an athlete using some of the heat adaptation advice from our listener community to help prepare for altitude, and the athlete went on to win a European uphill running title by over two minutes