The Aerobic Edge

Most runners who think they have low iron have never had the right test. And most who supplement for it never needed to.Dr Alannah McKay is a Senior Lecturer at the Mary MacKillop Institute for Health Research, Australian Catholic University, where she studies iron metabolism in athletes. She trained full-time as a ballet dancer from twelve to eighteen and thinks she was iron deficient through most of it — never tested, never treated. Her PhD, done in partnership with the Australian Institute of Sport, was awarded the Dean's List honour, and she now works alongside Professor Louise Burke on female athlete physiology.In this episode:What ferritin actually measures, and why a haemoglobin test alone tells you almost nothingThe three stages of iron deficiency — and where you can still interveneWhy the duration of your run matters more than the intensityHepcidin: the hormone that blocks iron absorption for hours after trainingThe thirty-minute window after a run when absorption is bestWhy "100mg" on a supplement bottle is often 20mg of what countsFerrous sulphate vs bisglycinate — and what the evidence actually supportsWhat happens to your iron across a hard training block or at altitudeHome ferritin tests, and why she's not ready to recommend them yetHow often a recreational runner should realistically get screened⚠️ Educational only — not medical advice. Supplementing iron without testing carries real risk, including for people with undiagnosed haemochromatosis. Talk to your doctor before changing anything.Chapters01:00 From ballet to iron research02:00 What iron does in the body05:00 Ferritin, haemoglobin and the three stages08:00 How iron is absorbed — and what blocks it11:30 Who's most at risk16:30 Hepcidin: why training blocks absorption20:00 The window after your run23:30 Low carb, keto and iron25:00 Haem vs non-haem, and vitamin C32:00 Can you have too much iron?34:30 Supplement forms37:00 Symptoms, and why fatigue is a poor signal39:30 How often to get screened40:30 Home ferritin tests43:00 Hard training blocks and altitude47:00 Dosing: elemental iron, timing and alternate days54:00 What she'd study nextFind Dr Alannah McKayLinkedIn: linkedin.com/in/alannah-mckayACU profile and email: acu.edu.auGoogle Scholar: scholar.google.comBook a free 30-minute callI'm Joost, running coach at Pace Buddies. I coach recreational runners using an aerobic-first approach — building the engine properly before layering speed on top, instead of the other way round.If this episode left you wondering whether something in your own training is holding you back, book a free thirty-minute call. No pitch deck, no pressure. We look at what you're actually doing now, where the gaps are, and whether coaching would help — and if it wouldn't, I'll tell you that.Book your free call at pacebuddies.comThe Aerobic Edge is an evidence-based endurance podcast for recreational runners. New episodes with researchers, coaches and athletes who actually know what they're talking about. Follow the show so you don't miss the next one.Instagram: @pace.buddies

Every fuelling guide tells you to take as many grams per hour as your gut can handle. Prof. Tim Noakes has spent four years arguing the number you actually need is closer to ten.His position is contested. Prof. Louise Burke argues the opposite, and they published a three-part debate against each other in the American Journal of Clinical Nutrition in May 2026 — her case, his case, and a joint consensus. All linked below.Tim Noakes is emeritus professor at the University of Cape Town, author of Lore of Running, and has been in the field since 1976 as both researcher and runner. His 2026 Endocrine Reviews paper works through 160+ studies to argue that endurance performance is limited by blood glucose and the brain monitoring it, not by muscle glycogen.We go back further than the paper: the day in December 2010 he changed his mind about carbohydrate, what it cost him, his own type 2 diabetes diagnosis despite decades of marathons, and the graph he'd shown hundreds of times without noticing what was in it.Also: what hypoglycemia actually feels like and why it reverses in ten minutes, what "low carb" means in real grams, fat oxidation above 1.5 g/min, industry funding in sports nutrition, and what any of it means at 40 to 50k a week.THE PAPERSEndocrine Reviews review: https://doi.org/10.1210/endrev/bnaf038The 10 g/h triathlete trial: https://doi.org/10.1152/ajpcell.00583.2024THE BURKE DEBATE (Am J Clin Nutr, May 2026)Burke — Yes: https://doi.org/10.1016/j.ajcnut.2026.101268Noakes — No: https://doi.org/10.1016/j.ajcnut.2026.101269Joint consensus: https://doi.org/10.1016/j.ajcnut.2026.101271Prof. Noakes co-founded Nutrition Network and The Noakes Foundation, both built around low-carbohydrate nutrition — discussed openly in the episode. For information only, not medical advice.ABOUTThe Aerobic Edge is an evidence-based endurance running podcast hosted by Joost, running coach at Pace Buddies. Aerobic-first marathon coaching for recreational runners.Book a free 30 min consultation on: https://pacebuddies.com

There comes a point in a race where it stops being about fitness. Deena Kastor — Olympic marathon bronze medallist and American record holder for nineteen years — is unusually specific about what to do when that moment arrives.We cover where her mental training started under coach Joe Vigil, the hill where she changed the words in her own head, and the practices she kept for decades:a daily gratitude list, and building joy into the sessions she dreaded. She also explains what an easy run is supposed to feel like (her Kenyan teammates called it a massage), how she handles start-line nerves with three memorised reasons she should succeed, and what she does in the last third of a marathon when it starts to fall apart.She also pushes back on the usual line about comparison, and on what to prioritise when you get injured.0:00 Intro1:53 Who Deena Kastor is5:22 Where the mental training started10:57 What an easy run should feel like16:09 Building joy into your week27:02 Reframing disappointment33:29 Start-line nerves36:11 The last third of a race44:01 Comparison48:21 Injury55:01 One takeawayBook: Let Your Mind Run. Instagram: @deenakastorWebsite: deena-kastor.comCoaching: pacebuddies.com

Most runners assume nasal breathing works because it gets you more oxygen. It doesn't — and today's guest explains what's actually going on instead. Zack Kramer, a strength and conditioning coach who rebuilt his practice around breathwork after years in CrossFit, walks through the real mechanism behind nose vs. mouth breathing: it's not oxygen uptake, it's CO2 tolerance.We cover what functional breathing actually looks like day-to-day, why mouth breathing becomes a hidden habit for so many runners, how to train your diaphragm like any other muscle, and a simple pre-run warm-up that speeds up nasal adaptation. Zack also shares his own month-long transition to full-time nasal breathing — including what didn't work.KEY TAKEAWAYS1. Nasal breathing isn't about getting more oxygen in — runners are already near-saturated (95%+). It's about CO2 tolerance, which delays the urge to breathe harder at a given pace.2. Nasal adaptation typically takes about a month of consistent practice; committing fully (24/7, including sleep) speeds it up.3. The diaphragm is a trainable muscle — a tired diaphragm pulls oxygen-rich blood away from your legs and arms before it pulls from anywhere else.4. A short CO2-buildup warm-up (exhale breath holds, ~2 minutes) can shortcut the rough first 5–10 minutes of a run.5. Chronic nasal issues (deviated septum, congestion) are common and manageable with nasal dilators — full nasal breathing isn't an all-or-nothing requirement.* Website / coaching: http://athletebreathcoaching.com* Instagram: https://www.instagram.com/athletebreathcoach/PaceBuddiesWebsite / coaching: http://pacebuddies.com* Instagram: https://www.instagram.com/pace.buddies/* Strava: @pace.buddiesChapters00:00 Episode preview00:38 Welcome & Zack's background — football to CrossFit to breathwork03:36 Breathwork courses that shaped his approach (Oxygen Advantage, XPT)05:20 What is functional breathing?07:33 Why nasal breathing is so hard to maintain09:46 Why nasal breathing matters — filtration & nervous system14:21 CO2 tolerance introduced15:39 What CO2 actually is, and why tolerance matters18:57 Does CO2 tolerance improve performance?21:31 Adaptation period & living with chronic nasal congestion22:10 Nasal dilators — show and tell25:43 Where to start with a runner28:25 How long does nasal adaptation actually take?30:35 Running with low-intensity nasal breathing problems34:42 The oxygen myth — debunking "mouth breathing = more energy"36:04 Training your diaphragm like a muscle39:03 Why a tired diaphragm steals blood from your legs40:31 Gear demo: the Breather Fit device42:46 Gear demo: the Isocapnic device43:44 How to actually use the devices — sets, reps, progression46:18 Breath training during intervals and rest periods48:12 The pre-run warm-up that speeds up adaptation52:27 Breathing for relaxation and recovery55:09 365-degree breathing technique58:25 How to practice belly, back, and side expansion59:17 Where to find Zack & closing

Most runners try to fix their form by chasing numbers — 180 steps per minute, a midfoot landing, a shorter stride. Paul Mackinnon thinks that's the wrong end of the problem.Paul runs The Balanced Runner in Melbourne and has spent close to a decade coaching running technique full time, working with Olympians like Galen Rupp and Brett Robinson alongside recreational runners with sore knees. His argument: cadence and foot strike aren't settings you adjust. They're outcomes of how the rest of your body moves. So he starts at the top — the arms and torso — and lets the legs reorganise underneath.We get into where the 180 rule actually came from, why forcing a foot strike can move an injury rather than fix it, and how he uses an old way / new way comparison so runners can feel a change instead of being told about it.I did a session with Paul before recording this, so some of what you'll hear I felt myself.Paul Mackinnon* Website: https://tbrunner.com* Instagram: https://instagram.com/thebalancedrunnerJoost Dekker — Pace Buddies* Website: https://pacebuddies.com* Free 30-minute consultation: http://pacebuddies.comChapters00:00 Intro00:54 From field hockey to running technique03:04 Canberra, dirt trails, and feet that sounded different04:53 Why physics has to come first06:40 What a first session actually looks like09:11 Feel it before you change it10:33 A word from Pace Buddies11:08 Why top-down instead of chasing cadence12:28 The arm swing: where it starts14:39 How arms change your foot strike17:59 What a good arm swing feels like20:15 Elbows, not hands22:29 Letting the athlete make the choice23:22 Old way, new way26:37 One cue at a time31:11 How long before it becomes a habit34:03 Better is better37:11 Does technique make you faster?39:36 The 800m data, clarified40:51 The 180 cadence rule44:18 Stride length and cadence are two levers47:27 Why your watch data doesn't tell the whole story49:28 Heel, midfoot, forefoot — does it matter?53:49 How to spot overstriding yourself55:59 Where to find Paul1:00:39 Outro