He Fixed Sabalenka's Serve. Now He's Working With Coco Gauff | Gavin MacMillan

Gavin MacMillan spent years building athletes nobody expected to make it — boxers, hockey players, tennis pros. Then Aryna Sabalenka hired him, and the tennis world started paying attention. In this episode, Gavin breaks down the serve transformation that took Sabalenka from 6 double faults in a single final to 6 double faults across an entire tournament. He explains why 99% of strength coaches in tennis are operating on the wrong principles — and why bigger, faster, stronger is the biggest lie in the sport. He's now working with Coco Gauff. And he has thoughts. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🎾 WHAT WE COVER IN THIS EPISODE → Why conventional weight training is actively hurting tennis players → The Federer "toothpick" principle: how elasticity beats muscle → Sabalenka's serve rebuild — the real story, step by step → What Gavin is working on with Coco Gauff right now → Why you can't think your way through a serve under pressure → The coaching lie: "I played it, so I can teach it" → What Freddie Roach taught Gavin about coaching under duress → The broken ATP/WTA system — and why nobody's fixing it → Caro Garcia on what she'd change about her career if she started over → Why tennis is the single hardest sport in the world to succeed in professionally ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ⏱ CHAPTERS 01:00 Gavin's background — 7 sports, hockey, losing his mom at 15 02:00 Narcissistic tennis parents & the crystal ball problem 03:30 Why tennis is the hardest sport in the world to succeed in professionally 06:00 Tennis vs the fight business — the only comparable mental challenge 07:30 Inside boxing: weight cuts, Cotto vs Canelo, and the A-side 10:30 Why conventional weight training is destroying tennis players 12:00 Force vs power — the Soviet training science nobody in tennis is using 13:00 Federer's toothpick body vs Nadal — the real difference explained 15:00 The door analogy — why bigger muscles increase injury risk 18:00 Why there's almost no science in tennis coaching 20:00 Gavin's live analysis of Caro Garcia's game 22:00 Caro's shoulder injury & the 22,000 serves per year problem 25:00 The insane tennis calendar — no other professional sport does this 28:00 Instagram fitness coaches on tour & the science nobody uses 29:00 Technical flaws in the modern game — you cannot hide them anymore 32:00 Federer's on-the-run forehand & why Sampras would dominate today 35:00 The skills gap — why top players still can't execute the basics 37:00 Gavin joins Coco Gauff's team — his exact role 39:00 How long does it really take to change technique on a pro player? 42:00 Coco's serve numbers — the before and after 44:00 The Sabalenka serve transformation — the full story 47:00 The reps math — why "5-minute serve fixes" are for functional morons 48:00 What Freddie Roach taught Gavin about great coaching 51:00 One thing in the corner — simplicity under extreme pressure 56:00 The 70% first serve rule that made Sabalenka unbeatable 1:00:00 Advice to young players: what actually builds a career 1:01:00 The 85% rule — why going 100% loses Grand Slams 1:07:00 Women's tennis marketing — why the tour is failing its own players 1:11:00 Identity, mental health & living and dying with every point 1:18:00 The camera on Sabalenka after a loss — the tour's exploitation problem 1:22:00 Federer's parents — what Gavin learned meeting them at the Australian Open 1:24:00 Coco Gauff at 21 — changing her serve the week before the US Open 1:29:00 Caro: "I would have had a better team" — what she'd change about her career 1:31:00 Every athlete falls to their level of preparation — not one rises above it 1:34:00 George St-Pierre, stars aligning, and the luck factor in elite sport 1:37:00 The unlicensed conditioning industry — and why it's getting players hurt 1:40:00 Injury prevention: the right evaluation every player should have but doesn't 1:42:00 The serve biomechanics breakdown — why Rafter's motion damaged him and Federer's didn't ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🎙 ABOUT GAVIN MACMILLAN Gavin is a performance coach whose work spans professional tennis, boxing, hockey, and football. He built the physical and technical systems behind Aryna Sabalenka's transformation into a Grand Slam champion and is currently part of Coco Gauff's team. His methodology rejects conventional weight training in favour of plyometric, elasticity-based power development — informed by training science and decades of cross-sport experience. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🎾 TENNIS INSIDER CLUB The inside story of professional tennis — hosted by Caroline Garcia (former World No. 4, 2022 WTA Finals Champion) 📺 Subscribe: @tennisinsiderclub 📸 Instagram: @tennisinsiderclub #tennis #sabalenka #cocogauff #tennispodcast #tenniscoaching #wta #grandslam #carolinegarcia #performancecoaching #tennisinsiderclub