The Aerobic Edge

Most runners have tried to fix their form at some point. Push off harder, use your glutes, land under your hips. It feels awkward, it feels harder, and after a week you go back to how you always ran.In this episode of The Aerobic Edge I talk with Fredrik Zillén, a running technique specialist from Stockholm who has filmed runners with 3D motion-capture cameras in his studio since 2014, from people coming off the couch to national-team athletes. His view: a heavy landing or a short stride is usually a consequence of something happening higher up in the body, so that is where he starts.In this episodeWhy trying to push off harder can work against you, and what your glutes are actually doing near toe-offThe muscle Fredrik would train if you could only train oneWhere your speed goes when you get tired, and as you get olderWhy a good technique change should feel easier right awayWhy the same pace can feel so different on a treadmillHow to run downhill faster without wrecking your quadsWhat you can check yourself with just a phoneChapters00:00 How Fredrik got into running technique07:30 Who walks into his studio11:05 Power from the hip and core15:50 What he sees in the first four seconds18:35 Same knee, two ways of running22:15 Running technique as a dance33:45 Why engineers struggle with running form36:40 Cadence, energy and pace38:25 Push-off and the glutes48:10 The soleus: the muscle for distance runners53:25 Film yourself56:55 Getting tired, getting older59:55 Why the treadmill feels different65:05 Downhill running72:30 Where to find FredrikAbout Fredrik ZillénRunning technique specialist based in Stockholm. Former journalist, athletics coach since his teens, and full-time running biomechanics coach since 2010.Website and online course: fredrikzillen.comYouTube: Fredrik Zillén – Running Technique SpecialistDisclosure: I have taken Fredrik's online course myself.Train with meI coach recreational runners one-on-one, mostly for the half and full marathon. We build your aerobic base first, then add speed, with your easy running guided by heart rate.Book a free 30-minute call · pacebuddies.comTymewearA chest strap that measures your breathing as well as your heart rate, so you can see your thresholds without a lab. I'm an affiliate partner, and I only work with products I believe in.tymewear.com/PACEBUDDIESTW · Code: PACEBUDDIESTWFollow The Aerobic EdgeYouTube · InstagramIf this episode helped you, follow the show. It helps other runners find it.Fredrik's views come from his coaching practice and his own measurements. Some of the studies he mentions, including the treadmill environment and feedback studies, we could not verify. This episode is for education, not medical advice. If you have pain, see a qualified professional.

Two-time Olympic champion Alistair Brownlee on why easy runs should be truly easy, why he thinks hard sessions are only the icing on the cake, and how he learned to simplify fueling after a tough race in Kona.In this episode:Alistair's path from age-8 triathlete to Olympic gold, including finishing 12th in BeijingWhy he ran easy at 5:00/km while running a 28-minute 10K, and his view on volume and dose-responseWhy he thinks many amateurs do too little easy training and don't make it easy enoughHis view of hard sessions as the "icing on a small cake"Heat training: how he got into it, how he thinks it works, the risks, and why you should never do it aloneHow recreational runners can think about core temperatureSimplifying fueling: practice it at least five times at race intensity and race rateHydration and sodium: weigh yourself before and after, and what Alistair does and doesn't replaceLinks:⁠True Fuels⁠ (Alistair's own brand)⁠My conversation with Arnar Lárusson about training by ventilation⁠⁠Get Tymewear⁠ (coupon code: PACEBUDDIESTW)The advice in this conversation is Alistair's personal view as a former professional athlete. It is not medical advice. Ask a professional before you change your training or fueling.Disclosure: I'm a Tymewear affiliate and may earn a commission if you buy through my link.⁠Download the free Super Base starter planChapters:0:46 Alistair's Start in Triathlon2:53 Three Olympics: From 12th in Beijing to Gold5:21 Aerobic Base: Easy Runs That Are Truly Easy7:48 How Much of Training Was Hard?8:38 Why Slowing Down Is Hard and Key10:06 How Alistair Judged "Easy"11:45 Hard Sessions Are the Icing on the Cake13:52 A Word About Tymewear15:05 The Pyramid and Consistency15:32 Training for the Ironman17:38 Heat Training: Where It Started19:51 How Heat Training Works22:09 Heat Training for Hot Races24:32 Heat Illness and Knowing When to Stop26:01 Practical Ways to Heat Train27:50 Monitoring Core Temperature30:42 True Fuels and Core Control32:55 Alistair's Experience With Core Control35:10 Staying Cool on Race Day38:15 Kona Ironman: What Went Wrong With Fueling41:22 Practice Your Fueling Five Times42:57 Hydration and Sodium47:52 Building a Fueling Plan Into Marathon Training50:40 Alistair Today51:56 Where to Find AlistairAbout Alistair Brownlee: two-time Olympic triathlon champion (London 2012 and Rio 2016), professional athlete for 18 years and founder of the sports nutrition brand True Fuels.

How accurate are training zones built on a percentage of max heart rate or VO2max? In this episode, Arnar Lárusson, founder of Tymewear, explains why he thinks those zones can land in the wrong place, what VT1 and VT2 are, and how ventilation can be used to guide training.In this episode:Why percentage-based zones can put you in the wrong zone, according to ArnarWhat VT1 and VT2 mean for fuel use, CO2 and your training zonesWhy heart rate can drift while ventilation stays steady (Arnar's example comes from cycling research)Lactate versus ventilation as a window into your effortHow VT1 and VT2 are measured, and why the talk test is unreliable for finding VT1How to use VT1 for easy runs and VT2 for marathon-pace workHow fast Arnar's users report progress after changing their zones (4 to 12 weeks, anecdotal)5:34 Engineering Meets Physiology8:55 Why Ventilation Matters for Runners15:09 Why % of Max Zones Miss VT1 and VT219:12 Personalizing Your Training Zones26:20 Ventilation vs. Heart-Rate Drift31:41 Lactate vs. Ventilation35:45 Measuring VT1 and VT239:46 Practical Training with Ventilation54:30 How Fast Can You Improve?57:49 What's Next for Tymewear?About Arnar Lárusson: founder of Tymewear, a chest strap that measures heart rate and breathing. Background in mechanical engineering, including prosthetics and exosuits.Links:Get Tymewear (coupon code: PACEBUDDIESTW)Tymewear on YouTubeTymewear on InstagramNote: the figures in this conversation (non-responder rates, sensor validation, fatigue data) are Arnar's own claims. Check the research yourself before changing your training.Disclosure: I'm a Tymewear affiliate and may earn a commission if you buy through my link.Download the free Super Base starter plan

Not overtrained – under-fuelled? Dr Trent Stellingwerff, a lead author of the IOC's REDs clinical assessment tool, explains the signs to watch for and what to do about them.Your easy runs feel hard, you're getting sick more often and your sessions are inconsistent. The usual advice: you're overtrained, back off. Trent thinks that advice is often wrong. In his team's review of the classic overtraining studies, 18 of the 21 that reported nutrition showed an energy or carbohydrate shortfall during the overload period.We cover what energy availability is, why the diagnostic tool doesn't measure it, symptoms you can spot without a lab, how under-fuelling leads to stress fractures, and the one simple equation worth knowing.Free 30-minute call with JoostWant a coach to look at your training and fuelling with you? Book a free 30-minute call at Pace Buddies, online running coaching for recreational runners. We'll talk through your goals, your current training and what's getting in the way.Book your free call · pacebuddies.comTimestamps00:00 Cold open: a month of not eating00:30 Intro01:48 Trent's background04:00 Why Trent studies under-fuelling06:30 Pregnancy, breastfeeding and under-fuelling10:17 Overtraining vs REDs14:01 A quick word about Pace Buddies15:42 18 out of 21: what old overtraining studies missed19:48 What energy availability actually is22:38 Spring classics: bad race days, fine weekly average25:31 Why you shouldn't calculate it yourself28:57 Fasted running: risk and reward31:52 Race weight and the weight-loss trap34:30 The symptom list39:14 How under-fuelling causes stress fractures42:20 What a runner can actually do47:20 Why your watch is off by 30%49:48 Why the diagnostic tool ignores energy intake51:47 One calorie per kilo per kilometre55:30 How long does recovery take?57:28 REDs and eating disorders are not the same59:19 The study he'd run with unlimited fundingThe quick versionEnergy availability = energy intake minus the energy cost of training, corrected for fat-free mass. It is not the same as a calorie deficit: one low day is fine, the pattern is the problem.Rough cost of a run: 1 kcal per kg body weight per km. It dates from the 1960s, was built on a flat treadmill, and falls apart on hills and when walking.Don't try to measure your way out: watch and app calories can be off by about 30%. Watch the symptoms instead.First step: add roughly 300–400 kcal of carbohydrate around training, spread food across the day, and see how you feel after a week.Key papersOvertraining vs REDs: shared pathways, symptoms and complexities (the 18-of-21 review)IOC REDs Clinical Assessment Tool (CAT2): scientific rationale2023 IOC consensus statement on REDsLow energy availability and bone injury in elite distance runnersMore of Trent's work on PubMedFind TrentWomen's Health and Sport Performance Institute (Boston) · Canadian Sport Institute Pacific (Victoria)DisclosureTrent previously spent six years in R&D at PowerBar (Nestlé Research Center) and has no current commercial interest in anything discussed.This episode touches on eating disorders. REDs and eating disorders overlap but are not the same thing. Nothing here is medical advice or a diagnostic tool. If several of the symptoms sound familiar, see a physician.

You've done the rehab. The exercises feel fine. But running still doesn't — and nobody seems to own that part of the process.Irish running coach Mark O'Mahony works with recreational runners in exactly that gap: sometimes alongside a physio, sometimes long after one has signed them off. He came to running sideways — he fought Muay Thai professionally, then finished a hundred-mile race on seven weeks of training, which he does not recommend.He won't hand out a list of exercises, and he explains why. What he gives instead is the layer underneath: how he reads pain as information, why morning stiffness is his main signal, what he does when someone's response is worse than expected, and why he only ever changes one thing at a time.In this episode:Why the gap between doing the exercise and handling running is where comebacks failMorning pain as a baseline — settled versus fluctuatingWhy pain-free during the run tells you less than the next morningThe runner whose foot wouldn't settle until they counted their steps at workWhat he does when rehab gets skipped, or a race no longer fits the timelineWhere his job as a coach ends and a clinician's beginsMark is a coach, not a clinician, and he's clear about that line throughout. Nothing in this episode is medical advice. If something isn't improving, get it looked at.Find Markcoachmarkomahony.comInstagram: @mark_omahony_runningAbout Pace BuddiesI'm Joost, a running coach working with recreational marathon runners — mostly people fitting real training around a job and a family. Aerobic-first, and adjusted to how your body is actually responding rather than to what the calendar says.Free 30-minute call, no pitch: cal.eu/pacebuddies/freecallCoaching and training plans: pacebuddies.com