The Endurance Science Podcast with Matt Carpenter

In this episode, I dives deep into the science of caffeine, revealing how understanding its mechanisms, dosing, and timing can help endurance athletes maximise their performance safely and effectively.Main topics:The science behind how caffeine enhances endurance performanceOptimal caffeine dosing strategies (3-6 mg/kg) and the effect of individual differencesTiming of caffeine intake before and during races for maximum benefitThe history of caffeine's status in anti-doping regulations and its legal use todayDifferences between coffee and pure caffeine supplementsPractical tips for training and race day caffeine useThe importance of personal experimentation and understanding individual responses

For as long as I can remember, I was told that lactate was the enemy, the toxic waste product that made my legs burn and forced me to slow down. It turns out almost everything I believed about it was wrong. In this episode, I trace the remarkable story of how lactate went from metabolic villain to one of the most important molecules in exercise physiology. I start with George Brooks, the UC Berkeley professor who spent four decades building the lactate shuttle theory, the idea that lactate isn't waste but a fuel, a gluconeogenic precursor, and a signalling molecule that shuttles between cells, tissues, and organs. Then I dig into a stunning 2023 paper from Craig Thompson's lab at Memorial Sloan Kettering that takes the story even further: lactate doesn't just feed the mitochondria, it activates the electron transport chain without even being metabolised. It's a messenger that tells your mitochondria to produce more ATP, suppresses glycolysis, and shifts your energy system toward oxidative phosphorylation. I explore what all of this means for how we think about the lactate threshold, pacing, interval training, recovery, and even immune function. If you've ever pushed into that burning zone on a hard run or ride, this episode will change how you think about what's happening inside your body.References:Cai, X. et al. (2023). Lactate activates the mitochondrial electron transport chain independently of its metabolism. Molecular Cell, 83, 3904–3920.Brooks, G.A. (2018). The Science and Translation of Lactate Shuttle Theory. Cell Metabolism, 27, 757–785.Brooks, G.A. et al. (2022). Tracing the lactate shuttle to the mitochondrial reticulum. Experimental & Molecular Medicine, 54, 1332–1347.Hui, S. et al. (2017). Glucose feeds the TCA cycle via circulating lactate. Nature, 551, 115–118.Leija, R.G. et al. (2024). Enteric and systemic postprandial lactate shuttle phases and dietary carbohydrate carbon flow in humans. Nature Metabolism, 6, 670–677.Brooks, G.A. (2023). What the Lactate Shuttle Means for Sports Nutrition. Nutrients, 15(9), 2178.

Get equipped with essential tools to critically read and evaluate research claims, especially in the world of sports science and endurance performance. This episode unpacks the pitfalls of predatory publishing, how to spot misleading studies, and the importance of understanding the broader body of evidence to make informed decisions.In this episode:The importance of not relying on single studies; why a body of research and systematic reviews are critical for true understandingWhat predatory publishing is, how it misleads athletes and consumers, and how to use Jeffrey Beals’ list as a resource for evaluating journal credibilityRed flags in research papers: lack of transparency, superficial peer review, misleading impact factors, aggressive solicitation tacticsHow social media and marketing exploit poor quality studies and cherry-pick data to promote supplements and gadgetsPractical steps to critically evaluate research: checking study design, conflicts of interest, replication, and alignment with meta-analysesThe hierarchy of evidence, from anecdotal reports to randomised controlled trials and systematic reviews, and why multiple replicated studies are necessaryThe myth of “magic” supplements and why one promising study doesn’t prove effectivenessHow to distance yourself from misinformation and make evidence-based choices in endurance training and nutrition

In this episode I answer questions that you've sent in, covering nomio, beetroot juice, bicarb, collagen and training-based questions, as well as a big announcement towards the end!Please leave a rating if you're enjoying the podcast!Q&A's will be monthly, let me know any questions you'd like covered.See you next week.

In this episode I dive into a topic I've been studying for the past 10 years - the impact of ketogenic diets on endurance performance.I talk about both the theory, research findings and social media commentary, as well as my own journey of 'belief' regarding keto. Twitter thread mentioned: https://x.com/louisemburke/status/1289505145479294976?lang=en

Ever wondered why your muscles burn during a hard effort and whether you can do anything about it? In this episode, I break down the science of buffering agents: supplements designed to combat the acid build-up that contributes to fatigue during intense exercise. Starting with the basics of why our muscles produce hydrogen ions and how our body's natural buffering systems work, I walk through the major players, including sodium bicarbonate, beta-alanine, sodium citrate, and lactate salts, explaining how each works, who they're best suited for, and what the research actually says. I explore the intensity and duration sweet spot where these supplements have the strongest evidence, before diving into exciting emerging research suggesting buffering agents might also benefit longer endurance events. The episode wraps up with practical dosing protocols, timing strategies, and tips for managing the well known side effects. Whether you're a middle distance athlete, an endurance cyclist, or just someone who wants to understand the science behind the burn, this one's for you.

In this episode of the Endurance Science Podcast, I discuss the critical role of fat oxidation in endurance exercise. I discuss how fat burning works during exercise, its importance in various event durations, and the methods to enhance fat oxidation. The discussion highlights recent research findings, practical strategies for athletes, and the significance of dietary modifications to improve performance. While carbohydrate consumption is often prioritised, understanding and improving fat oxidation is essential for long-distance endurance athletes, and that's what this episode is all about.TakeawaysFat oxidation is crucial for endurance performance, especially beyond two hours.Carbohydrate is the primary energy source at higher intensities, but fat stores are virtually unlimited.Research shows a correlation between fat oxidation rates and performance in long-distance events.Fat oxidation becomes increasingly important as exercise duration extends beyond two hours.Training volume significantly enhances the body's ability to burn fat.Reducing carbohydrate intake can improve fat oxidation rates.Periodizing carbohydrate intake may help maintain performance while increasing fat oxidation.Testing fat oxidation rates can provide insights into an athlete's metabolic efficiency.Athletes should focus on both training and dietary strategies to optimize fat burning.Understanding the balance between fat and carbohydrate metabolism is key for endurance athletes.References:https://journals.physiology.org/doi/epdf/10.1152/japplphysiol.00855.2015https://link.springer.com/article/10.1007/s00421-016-3333-yhttps://physoc.onlinelibrary.wiley.com/doi/full/10.14814/phy2.70752

In this episode of the Endurance Science podcast, I dig deep into the complex role of carbohydrates in enhancing endurance performance. We discuss how carbohydrates are stored in the body, the physiological mechanisms behind their utilization during exercise, and the varying recommendations for carbohydrate intake based on exercise duration and intensity. The conversation highlights the importance of both muscle and liver glycogen, the impact of carbohydrate ingestion on performance, and the emerging research on carbohydrate mouth rinsing. Carbohydrates improve endurance performance through various mechanisms.Muscle glycogen is primarily stored in muscles, while liver glycogen helps maintain blood glucose levels.Carbohydrate ingestion during exercise can spare muscle glycogen and prevent hypoglycemia.The cephalic response to carbohydrate can enhance performance even without ingestion.10 grams of carbohydrate per hour can be sufficient for maintaining blood glucose during exercise.Individual responses to carbohydrate intake can vary significantly among athletes.Carbohydrate mouth rinsing may provide performance benefits without actual ingestion.Breakfast is crucial for maintaining liver glycogen levels before exercise.Carbohydrate needs differ based on the duration and intensity of the activity.Future research should focus on individual carbohydrate requirements for endurance athletes.References:https://journals.physiology.org/doi/full/10.1152/japplphysiol.00861.2025https://journals.humankinetics.com/view/journals/ijspp/21/2/article-p258.xmlhttps://journals.physiology.org/doi/full/10.1152/japplphysiol.91394.2008

Most supplements don't work, but this episode explores supplements that do have scientific evidence, exploring what supplements may improve performance, and the context surrounding each supplement. Though we can't cover every supplement that you may have heard of, this episode focused on 8 supplements that may be used to improve performance, all with varying degrees of evidence.

Electrolytes: Understanding the Controversy and MisconceptionsElectrolytes are everywhere in the world of endurance. In this podcast I explain why electrolytes exist in the endurance space, what their function is, who should use them, and importantly, who doesn't need them.TakeawaysElectrolyte supplements are not necessary for most peopleDaily electrolyte consumption can have negative health implications

It's time to start a podcast! This podcast aims to be informative and entertaining, with me deep diving into topics, interviewing experts and people working in the field, and running regular q&a's.Let's bring evidence to the world of endurance exercise.