IMO 37 - Losing Weight to Run Faster Updates, Dynafish Going Crazy In China and Attempting The Marathon World Record in Jeans
Sweat Elite PodcastShow Notes
Welcome back to another unstructured In My Opinion episode. Matt shares an update on losing weight to run faster, the explosion of Chinese super shoes and Dynafish, a potential marathon world record attempt in jeans, HYROX plans, coaching updates and why he has backed away from frequent sauna use. Be coached by Matt: https://www.sweatelitecoaching.com/coaching-2026 Join the Shareholders Club / Private Podcast Feed: https://www.sweatelite.co/shareholders Matt Instagram: https://www.instagram.com/mattinglisfox/ Matt Training Log - Strava: https://www.strava.com/athletes/6248359/ Contact Matt: [email protected] Matt opens with updates on the Sweat Elite Podcast, including changes to the private feed, a new weekly subscriber hangout and a small number of coaching opportunities becoming available. The main discussion centres around losing weight to run faster, prompted partly by Josh Kerr's visible change in body composition alongside his recent performances. Matt reflects on his own marathon career, including a period where gaining roughly 3.5 kg coincided with slower marathon performances before intentionally losing around 4 kg and returning to consistent sub-2:20 racing. Matt explains the simple approach he has personally used - maintaining a modest calorie deficit on most days while prioritising high-volume, satiating foods, then aggressively increasing carbohydrate intake around important training. Rather than trying to remain perfectly fuelled every hour of every day, he discusses using roughly 12-hour windows before major sessions and races to maximise carbohydrate availability, followed by substantial refuelling afterwards. He also discusses why he avoids obsessing over daily scale weight, instead looking at longer-term trends and carbohydrate cycles. Matt believes intentional weight-loss phases should generally be relatively short - around 6 to 12 weeks for most athletes and rarely beyond 20 weeks - rather than becoming a permanent part of training. The conversation also tackles the stigma surrounding weight loss in endurance sport, RED-S, disordered eating and the potential danger of becoming obsessed with numbers. Matt stresses that this approach is only relevant to runners who genuinely have weight they can healthily lose and that improving performance should never come at the expense of long-term health. Later in the episode, Matt shares updates from the Chinese running shoe world, including upcoming laboratory testing of several Chinese super shoes and the rapid growth surrounding Dynafish. He discusses distribution delays, demand in China and plans for bringing more shoes into international markets. Matt also considers racing the Sydney Marathon in jeans and potentially attempting the marathon world record for running in jeans, before discussing his future racing ambitions, interest in trying HYROX and whether an Ironman is something he would ever consider. Finally, Matt explains why he has stopped frequent sauna sessions after noticing increasing fatigue and deteriorating training quality, despite initially introducing sauna as part of his marathon preparation. Topics: 00:00 Welcome and Setup 00:27 Topics and Context 02:46 Pro Podcast Changes 03:46 Subscriber Hangouts 06:05 Coaching Spots Open 07:12 Why Weight Matters 08:18 Josh Kerr Example 09:45 My Marathon Weight Shift 14:41 Stigma and Pushback 20:08 Simple Weight Loss Framework 24:34 Carb Timing for Workouts 28:59 Risks and Obsession Trap 30:38 Carb Cycles Not Scales 31:44 Avoid Number Obsession 32:47 Who Should Cut Weight 35:46 Coaching And Stigma 37:36 Chinese Shoe Lab Tests 39:39 Dynafish Distribution Plans 43:36 Sydney Jeans Marathon 45:40 Weight Loss And Future Goals 50:55 HYROX Versus Ironman 52:31 Sauna Fatigue Lesson 57:25 Wrap Up And Next Steps
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Matt reflects on a disappointing Melbourne Marathon after calf pain at 12K developed into a race-ending injury at 20K. An MRI revealed a 15cm grade 3B soleus tear, with evidence of an older injury in the same area—putting his Valencia Marathon plans in doubt. Train with Matt Fox: https://sweatelitecoaching.com/matt-fox/ Sweat Elite Supporters Club: https://sweatelite.co/supporters-club/ Globe Runners — Monte Gordo, Portugal (January 9–17, 2027): https://www.thegloberunners.com/monte-gordo-running-experience-2027/ Globe Runners — Lisbon, Portugal (February 20–28, 2027): For trip details and enquiries: https://www.thegloberunners.com/ Nutrition Coaching with Matt Fox: https://sweatelite.co/coaching/nutrition/ Personalised Nutrition Meal Plans: https://sweatelite.co/nutrition-meal-plans/ Matt Fox on Instagram: https://www.instagram.com/mattinglisfox/ Matt Fox on Strava: https://www.strava.com/athletes/6248359 Contact Matt: [email protected] After a buildup targeting 2:15, Matt explains how the race unfolded: settling into a pack running around 2:16 pace, managing the initial calf pain, and eventually stopping when it became too severe to continue. He shares why he has no regrets about the DNF—and why he wishes he had pulled out earlier. He revisits a calf twinge while testing shoes in May and considers possible contributors to the injury, including training load, trail running, tapering, weight loss and racing in the Puma Fast-R 3. The cause remains uncertain, and his recovery plan is still being worked out with his coach and physiotherapist, Kyle. The listener Q&A covers coping with repeated injury setbacks, keeping base training simple, adjusting training effort in heat and humidity, and finding value in Chinese super shoes. Matt also discusses possible recovery options, including PRP, and shares his views on peptides and anti-doping ethics. There are reflections on Melbourne's elite drink-station setup, Truett Hanes' marathon progress, and Jimmy Wheela's experience racing against Kipchoge. Matt also shares updates on Globe Runners training trips in Monte Gordo and Lisbon, his running shoe distribution business, nutrition coaching, and an upcoming six-month move to Portugal. Episode Chapters: 00:00 MRI Results: A 15cm Grade 3B Soleus Tear 00:47 Why the Injury Caught Me by Surprise 01:56 The Calf Warning Back in May 03:08 Melbourne Breakdown: Pain at 12K, Stopping at 20K 05:44 Can Valencia Still Happen? 06:32 Why I Wish I'd Stopped Sooner 07:04 The Positives from Melbourne Weekend 07:39 Portugal Plans and Races in Doubt 08:26 Globe Runners: Monte Gordo and Lisbon Trips 12:25 Running Shoe Distribution Business Update 16:42 Melbourne's Elite Bottle Tables 21:03 Listener Q&A: Weight Loss, GLP-1s and Racing Shoes 24:23 Truett Hanes' 2:23 and Olympic Trials Goal 25:10 Listener Questions on PED Testing 26:07 Melbourne as a Destination Marathon 26:51 Handling a DNF and Injury Setbacks 30:02 Building an Aerobic Base Without Overthinking It 32:56 Calf Recovery: Rest, Rehab and Considering PRP 33:53 Peptides, Injury Treatment and Anti-Doping Ethics 35:45 Jimmy Whelan, Kipchoge and Early Race Surges 37:43 Value Picks for Chinese Super Shoes 40:04 Possible Injury Factors: Trails, Taper, Shoes and Load 42:35 Adjusting Training in Heat and Humidity 45:07 Content Burnout and Moving to Portugal 47:42 Nutrition Coaching and What Comes Next
In this episode, I announce the next Globe Runners Portugal Running Experience in Monte Gordo, share the results of my latest DEXA scan after dropping from 86kg to around 70kg, and discuss what I learned about weight loss, bone health and nutrition along the way. I also share a remarkable 2:07 marathon performance off less than 100km per week and give my final update before racing the Melbourne Marathon this Sunday. LINKS Portugal Running Experience - January 9-17, 2027: https://www.thegloberunners.com/monte-gordo-running-experience-2027/ 1:1 Running Coaching: https://sweatelite.co/coaching/personalized-1-1/ Running + Nutrition Coaching: https://sweatelite.co/coaching/run-nutrition/ Nutrition Coaching: https://sweatelite.co/coaching/nutrition/ Personalised Nutrition Meal Plan: https://sweatelite.co/nutrition-meal-plans/ Instagram: https://www.instagram.com/mattinglisfox/ Strava: https://www.strava.com/athletes/6248359 Eastbound Running (Dynafish): https://www.eastboundrunning.com/ ABOUT THIS EPISODE I start this episode with something I'm really excited about - the next Globe Runners Portugal Running Experience, taking place in Monte Gordo from January 9-17, 2027. I explain why I've become increasingly interested in putting my energy into coaching, nutrition and creating running experiences rather than promoting products. A lot of that thinking developed during the months I spent detained in Japan, where I had a huge amount of time to read, write and think about what I actually wanted to work on. The Portugal experience will bring a small group of runners together for eight nights in Monte Gordo in the Algarve. We'll train together, eat together and explore southern Portugal, with optional day trips around the Algarve and to Seville in Spain. The €1,250 price includes four-star accommodation, three meals per day, airport transfers from Faro and transport for the organised excursions. There are only 16 places available. I then get into the results of my latest DEXA scan. In April I weighed 86kg at 22.5% body fat. Around five and a half months later, I'm approximately 70kg and my DEXA measured me at 8.5% body fat. One of the most interesting findings was my bone density. Despite losing roughly 16kg while returning to high-volume marathon training, my measured bone density improved between the two scans. I discuss the things I focused on throughout the process, including calcium-rich foods, vitamin K, vitamin D, sunlight exposure and consistent heavy strength training. I also talk more broadly about weight loss for runners, the genuine risks of low energy availability and RED-S, and why I think the conversation needs more nuance. Losing weight is not appropriate for every runner, but for athletes with excess body fat who want to reduce it, I believe it can be approached carefully while closely monitoring health, recovery and performance. I share an example from one of my nutrition athletes whose weight began dropping faster than planned. When his training performance started declining, we increased his energy intake and quickly got things moving in the right direction again. Then there's a shoutout to Adam Lipschitz, who just ran an incredible 2:07:20 marathon after averaging only around 96km per week over the previous 12 weeks. It's a fascinating example of just how individual marathon training can be and how more mileage isn't automatically better. Finally, it's Melbourne Marathon race week. I talk about where I think my fitness is compared with when I ran 2:18:41, the potential advantage I'm getting from the Puma Fast-R, the weather forecast, and why I believe a significant PB is possible if everything comes together. I also briefly discuss what comes next, including moving to Portugal, racing in Europe and potential starts at Alicante and Valencia later this year. TIMESTAMPS 00:00 - Welcome and Melbourne Marathon taper 00:29 - Reflections from my time in Japan 02:21 - Why I want to focus on run
Matt answers 15 listener questions about race weight, weight loss, carb cycling, recovery, fueling and running performance. PERSONAL LINKS 1:1 Running Coaching: https://sweatelite.co/coaching/personalized-1-1/ Running + Nutrition Coaching: https://sweatelite.co/coaching/run-nutrition/ Nutrition Coaching: https://sweatelite.co/coaching/nutrition/ Personalised Nutrition Meal Plan: https://sweatelite.co/nutrition-meal-plans/ Instagram: https://www.instagram.com/mattinglisfox/ Strava: https://www.strava.com/athletes/6248359 Eastbound Running (Dynafish): https://www.eastboundrunning.com/ ABOUT THIS EPISODE In this episode, Matt answers 15 questions submitted through YouTube about race weight, weight loss and running performance. Topics include losing weight while maintaining training quality, carbohydrate cycling, calorie deficits during a marathon taper, post-workout fueling, finding your ideal race weight, losing fat versus muscle, GLP-1 medications and heart rate, creatine and water weight, and whether the same weight-loss approach can work for shorter-distance runners and triathletes. Matt also shares his own experience dropping from around 86kg to 69kg, how body weight played a role in eventually breaking 2:20 for the marathon, and how he is approaching the final two weeks before the Melbourne Marathon. Later in the episode, Matt gives an update on his Melbourne Marathon goal, testing the Puma Fast-R 3, the upcoming Dynafish launch in Australia, New Zealand and the UK, and his move to Lisbon for six months. TIMESTAMPS 00:00 - Welcome and Scope 00:52 - Safety Disclaimer 01:56 - Why This Topic 05:00 - Sub-2:20 Breakthrough 09:49 - Post-Workout Carbs 11:34 - Calorie Deficit During a Marathon Taper 14:47 - Losing Muscle Mass 17:25 - GLP-1s and Heart Rate 20:46 - Weight Loss for Shorter-Distance Runners 27:23 - The Challenges for Triathletes 30:39 - Weekly Calorie Deficit Numbers 33:16 - Finding Your Ideal Race Weight 36:25 - Creatine and Water Weight 38:07 - Why Not Carb Load Every Day? 41:57 - Nutrition Coaching and Services 45:35 - Melbourne Marathon Update 47:11 - Dynafish Distribution Update 48:52 - Moving to Lisbon 49:24 - Final Wrap-Up This episode discusses intentional weight loss and calorie restriction in the context of endurance performance. It is not intended for people with a history of eating disorders, RED-S or low energy availability, or anyone concerned they may be at risk of these conditions.
Matt breaks down how to safely lose 5kg+ during a marathon block — using calorie deficits on easy days and big carb windows around hard sessions — so you can train hard and run faster. Matt Fox / Sweat Elite Nutrition Coaching: https://sweatelite.co/coaching/nutrition/ Run + Nutrition Coaching: https://sweatelite.co/coaching/run-nutrition/ Nutrition Meal Plans: https://sweatelite.co/nutrition-meal-plans/ Personalised Training Plan: https://sweatelite.co/personalised-training-plan/ Coaching: https://www.sweatelitecoaching.com/matt-fox/ Instagram: https://www.instagram.com/mattinglisfox/ Strava: https://www.strava.com/athletes/6248359 YouTube: https://www.youtube.com/@SweatElite Sweat Elite: https://www.sweatelite.co/ Matt talks about how to lose five kilograms or more in the ten weeks leading into a marathon — while still training hard and aiming to run faster. He pushes back on the old idea that you should finish all weight loss before the marathon-specific block, and shares how he's used this approach five times himself, including a recent stretch where he dropped nearly fifteen kilos. Matt walks through the method in plain terms: stay in a calorie deficit most of the week, track burn with a watch or rough math, log food with AI photo counting, and then flip into big carbohydrate windows around your two hardest sessions so quality workouts don't suffer. He lands on roughly an eight-hundred-calorie deficit on easy days — enough, on paper, to lose about half a kilo a week and five kilos over ten weeks. Matt is clear this is not for everyone. If you've dealt with an eating disorder, RED-S, or low energy availability — or you're already below a healthy weight — he says turn the episode off. For listeners who can safely lose the weight, he also covers strength work, bone-health basics, and where coaching or a meal plan fits if you want more accountability. Timestamps 00:01 Content warning & who should skip 00:36 The goal 02:20 The only rule that matters 03:43 How to track burn 05:33 How to track intake 06:11 Weekly structure: deficit + carb windows 08:00 Hard-session fueling 11:03 Easy-day eating 13:19 GLP-1 note (personal, not recommended) 14:55 The math (why ~800/day) 16:16 Injury-risk buffers 17:45 Risk framing 19:10 Coaching / meal plans Content warning & who should skip Eating disorders, RED-S, LEA, and already-lean athletes should not follow this advice. Aimed at people who can safely lose ~5kg+ and want to run faster. The goal Lose 5kg+ in the ~10-week marathon-specific block; Matt's personal and coaching experience; pushback on "never diet in the marathon block." The only rule that matters Calorie deficit = burn more than you eat. Tracking makes it workable; perfection isn't required. How to track burn Garmin (or similar) preferred. Rough guide: ~2,000 kcal/day for many men (5–7k steps); ~1,700 for many women; easy running ~700 kcal/hour; hard running closer to ~1,100 kcal/hour. How to track intake Photo-log every meal/drink in ChatGPT (or similar AI); build one daily log; close enough beats exact. Weekly structure: deficit + carb windows Most of the week (~5.5 days): solid deficit (~800 kcal/day as a working target). Around 2 hard sessions (e.g. Wed + Sun): stop deficit counting ~12 hours before; load carbs heavily before, during, and a few hours after. Hard-session fueling Example carb load ~400g in the pre-session window; in-session carbs often 70–100g/hour for men (women slightly lower); prioritize white rice, potatoes, bread, pasta in those windows. Easy-day eating High-volume, low-calorie foods (fruit, veg, lean protein); flavored soda water as a hunger/dopamine hack; ask AI for satiating low-cal meal ideas. The math (why ~800/day) ~7,700 kcal deficit ≈ 1kg fat; ~3,800/week ≈ 0.5kg/week ≈ 5kg in 10 weeks. Surpluses in carb windows are expected; the weekly total still lands if easy days stay consistent. Injury-risk buffers Start strength (esp. squats) ~1 month before die