The Aerobic Edge

Scott Johnston is one of the most respected endurance coaches in the world. As founder of Evoke Endurance and co-author of Training for the Uphill Athlete, he has coached athletes across skiing, mountaineering, trail running and road running. In 2025, both the men's and women's UTMB champions — Tom Evans and Ruth Croft — were coached by Scott.In this episode we dig into the foundation of endurance performance: the aerobic base. Scott explains what zone 2 actually is, why percentage-based calculators don't work, how to find your personal aerobic threshold with a free at-home test, and why most runners are unknowingly training in the wrong zone.We also cover aerobic deficiency syndrome, the vacuum cleaner analogy for lactate, and why consistency beats every magic workout you'll ever find on the internet.If you're a recreational marathon runner who wants to train smarter, this episode is the place to start.What we cover:How Scott went from ski coach to world-class endurance coachWhat aerobic and anaerobic actually meanWhy zone 2 is not a percentage of your max heart rateThe heart rate drift test — free, simple, and personalAerobic deficiency syndrome and how to fix itThe vacuum cleaner analogy: lactate as fuel, not wasteHow long does building a real aerobic base actually take?Why consistency is the only secret that worksLinks & resources:Evoke Endurance — evokeendurance.comAerobic Deficiency Syndrome (ADS): https://evokeendurance.com/resources/aerobic-deficiency-syndrome-ads/Heart rate drift test & aerobic assessment: https://evokeendurance.com/resources/our-latest-thinking-on-aerobic-assessment-for-the-mountain-athlete/Setting your heart rate zones: https://evokeendurance.com/resources/setting-your-hear-rate-zones/Book a free coaching call with Joost: https://www.cal.eu/pacebuddies/freecallPace Buddies — pacebuddies.com

In this episode, Joost sits down again with coach John Starrett to dive into one of the most overlooked phases in endurance training: bridge training.After building a strong aerobic base through the foundation, pre-super base, and super base phases, many runners jump too quickly into race-specific work. Bridge training fills that gap—safely introducing intensity, improving speed, and preparing the body for peak performance without increasing injury risk.This episode breaks down how to structure this critical phase and why it’s essential for long-term progress.What bridge training is and why it mattersHow to transition safely from base training to faster runningThe role of shorter recoveries and varied workoutsHow to improve lactate clearance and utilizationWhy most runners should avoid traditional 5K-style trainingHow to balance endurance, speed, and injury preventionThe importance of individualized coaching and feedbackHow to use races strategically to boost fitness and reduce injury risk1. From Base to PerformanceBridge training builds on the aerobic and structural gains from the super base phase. The goal is to make runners faster across multiple distances (5K to half marathon) before entering marathon-specific training.2. Endurance Spine & Structural RunsEndurance Spine Runs: Tempo efforts based on sustainable effort (roughly 90-minute pace)Structural Runs: Longer, slightly slower tempo runs that build durability and reduce injury riskThis alternating structure creates both strength and speed progression over a 5-week cycle.3. Smarter Speed WorkInstead of repetitive sessions, bridge training introduces variety:Cut-down workouts (progressing from slower to faster paces)Pyramid sessionsBroken temposLactate-focused workoutsThese sessions improve efficiency without overwhelming the body.4. Lactate as FuelYou’ll learn how specific sessions train the body to reuse lactate as energy, improving endurance and delaying fatigue—key for both shorter races and the marathon.5. The “B Workout” PrincipleWorkouts should feel controlled—not all-out.If you finish a session feeling like you could do more, you’re training correctly.Constant maximal efforts lead to injury and stagnation.6. Why Most Runners Train Too HardMany recreational runners follow elite-style interval sessions (like 8×1000m), which are often too intense and increase injury risk. Bridge training offers a safer, more effective alternative.7. Racing as a Training ToolStrategically placed races every 6–8 weeks:Provide performance benchmarksAct as high-quality training stimuliReduce injury risk through built-in taper and recoveryBridge training is where real performance gains start to happenVariety and progression are more important than intensity aloneEndurance remains critical—even when focusing on speedTraining must be individualized, not copied from templatesConsistency and injury prevention always come firstIn the next interview, Joost and John will break down marathon-specific training—how to convert this fitness into race-day performance.Have questions about your training or want help applying this approach?ConnectJoost (Host)Instagram: https://instagram.com/pace.buddiesWebsite: https://pacebuddies.comBook a free 30min discovery callJohn StarrettInstagram: https://instagram.com/stazzas_stableWebsite: https://stazzasstable.com/

Most runners assume that logging more miles automatically makes them better fat burners. The science says otherwise.In this episode, Joost sits down with New Zealand-based sports dietitian and researcher Mikki Williden (PhD, public health) to unpack one of the most misunderstood topics in endurance sports: metabolic flexibility. Mikki has a 2:55 marathon PB, has raced the Boston Marathon, the Southern Lakes Ultra, and the Grand to Grand Ultra — and she's spent 15+ years working with athletes on exactly this.What you'll learn:Why diet — not training volume — is the #1 driver of fat oxidationThe difference between low-carb and ketogenic for endurance athletesHow to time carbohydrates across your training week for better metabolic flexibilityWhat the research by Dr. Prins, Noakes & Kutnick on 10g of carbs/hour means for your race fuelingWhat "brain bonking" actually is — and how a small amount of glucose prevents itWhy endurance athletes need more protein than they think (and how to get it in)How to lose body fat without wrecking your trainingElectrolytes on low-carb: why sodium needs spike and what to do about itKey takeaway: Metabolic flexibility isn't about going keto. It's about shifting your daily diet to train your body to access fat at low intensities — so you can spare carbohydrates for when it really counts.About Mikki Williden:Mikki is a registered sports dietitian and PhD researcher based in New Zealand. She hosts the podcast Mikkipedia, where she interviews researchers and practitioners on nutrition, performance, and metabolic health. Find her at mikkiwilliden.com or on Instagram @mikkiwilliden.Free coaching call:Want to apply these principles to your own marathon training? Book a free call with Joost at cal.eu/pacebuddies/freecall.