8 Muay Thai Training Mistakes I’d Fix If I Started Again
I know you’re making Muay Thai training mistakes. Some of them are costing you right now. The rest will wait decades and then send you the bill.
You’re gassing out in the third round, so you run harder. Your kicks aren’t landing with power, so you kick more. It feels like the right answer because it’s what everyone tells you to do.
But you’re getting worse, and you can’t figure out why. I know because I made every one of these Muay Thai training mistakes myself.
Over nearly a decade of fighting and three decades coaching, I’ve broken my big toe on one foot, dislocated the big toe on the other, fractured ribs, separated a shoulder, and eventually needed hip resurfacing surgery from a career’s worth of needless wear and tear. I started competing at 32 with no coach and no corner, taught myself as I went, and by 40 I was UK ranked number four, beating fighters half my age. I’ve won fights and spent the night in hospital, lying there with electrodes on my chest, wondering how something so ordinary nearly ended me.
I’ve compressed everything I learned the hard way into the video below. If your training isn’t moving you forward, if you’re spinning your wheels and collecting injuries instead of progress, these eight lessons will show you exactly what to change.
Watch: 8 Lessons I’d Give My Younger Fighting Self
by Don Heatrick
@donheatrick
The Muay Thai Training Mistakes That Start With a Bad Diagnosis
Of all the Muay Thai training mistakes fighters make, treating the symptom instead of the problem is the one I see repeated most. You gas out in round three, so you run more. Your kicks lack power, so you kick harder. Your clinch fatigues quickly, so you clinch more. It’s logical on the surface, and it’s almost always wrong.
If you’re gassing out because your aerobic capacity isn’t generating enough energy, running harder won’t help. If your kicks lack power because your hip mobility is restricted, kicking more just reinforces the range you currently have. If your clinch fatigues quickly because your maximal pulling strength is low, more clinching won’t fix it. You cannot endure qualities you don’t have.
I use an IPO model from my engineering background to diagnose these problems. Input is the raw quality you develop. Process is how efficiently you transfer it, your technical skill. Output is what reaches the target, what your opponent feels. Most fighters keep adding to the process stage when the constraint is in the input, refining a delivery system that has nothing to deliver. Thais aren’t powerful, they’re efficient. They dominate the process stage (roughly 98% transfer efficiency), which means their biggest untapped gains are sitting in the input too. Diagnose which stage your constraint lives in before you reach for the fix.
The Muay Thai Overtraining Mistake That Cost Me a Hip Joint
My default was always do more. I was fit enough to recover, I was improving, so why doubt what was working?
I’ll tell you why. I’m in my fifties now, and I’ve already had hip resurfacing surgery in my left hip because of osteoarthritis from a high volume of kicking and running. My right hip is on borrowed time. I did way more than I needed to get the same results, and every unnecessary rep, every extra round, every session I did just because I could was compounding needless wear and tear. A cost you don’t feel until decades later.
The minimum effective dose isn’t just about training efficiency in the present. It’s about preserving your body for the long haul. Being fit enough to recover from excess volume is not the same as needing that volume to progress. If you can’t justify why a specific exercise or session is in your program, cut it. Targeted effort beats grinding effort, every single time. The body keeps a tally. It always does.
Training Through Pain: Why It’s One of the Costliest Muay Thai Training Mistakes
Training through pain is one of those Muay Thai training mistakes with compound interest. I’ve broken my big toe on one foot, dislocated the big toe on the other foot, broken ribs, fractured my elbow, separated my shoulder, and developed patella tendonitis and achilles tendonitis. All because I wouldn’t stop. I was a fighter who’d just run it off.
That attitude is great during a fight. In training, it’s a bloody liability, and the older you get, the more of a liability it becomes. A small amount of backing off at the right time can save you months of wasted time and missed opportunities. Backing off doesn’t mean stopping altogether. It means working around an injury, moving forward in other areas that don’t aggravate and slow up your rate of healing. Listen to your body. Short-term gain can end up a long-term loss, and long-term gain is where it’s at.
This applies to your brain health too. Research shows the accumulation of regular subconcussive blows is the real danger, not just the occasional heavy knockout shot. Technical sparring in Thailand proved to me that heavy headshots aren’t necessary in training. Save them for when you compete. Don’t make them part of your regular routine.
Confusing Fatigue With Progress: A Classic Among Muay Thai Training Mistakes
Confusing fatigue with adaptation is easily one of the most common Muay Thai training mistakes, and it took me years to spot it. For years I confused effort with progress. If a session left me knackered, I assumed it was working. I didn’t stop to ask whether the fatigue was actually producing adaptation, or just accumulating fatigue I’d eventually pay for.
Feeling destroyed is not the same as adapting. They’re different biological processes, and they don’t always overlap. You can run yourself into the ground for months and come out the other side no faster, no stronger, no fitter. Just more tired and more injured. I’ve done it. I’ve got the surgical scars to prove it.
The question I wish I’d asked earlier: is your training actually making you better or just making you feel tired? If you can’t answer that with something specific, a measurable improvement in a quality that matters to your performance, then you’re just grinding for the sake of it.
Muay Thai for Older Fighters: The Late Starter’s Advantage
I didn’t start fighting until I was 32. No coach, no corner, no ringcraft. I trained on mats. In my first year I won three area titles at three different weights, was selected for England at 34, fought at the world championships, and won a silver European medal. At 35 the amateur rules deemed me too old, so I turned pro. By 40 I was UK ranked number four, beating fighters half my age.
I didn’t retire because of age. I retired because of an elbow surgery that had nothing to do with being old, and everything to do with smashing my elbow down on top of opponents’ heads in the ring. Honestly, careful with that one.
My secret as a veteran fighter was my physicality. My S&C was so far ahead I could drown younger fighters in work rate. I was just a tough, relentless bugger. Late starters have advantages most people overlook. You’re more strategic about how you learn, you’re more efficient with your training time, and you’ve got the psychological maturity to handle setbacks. Believing you’ve missed your window is one of the most damaging Muay Thai training mistakes you can make. Most people give up on themselves without truly reaching their limits. Refusing to believe the story you tell yourself about your limits is what determines how far you go, not how early you start. The best time to plant a tree was 20 years ago. The second best time is now.
Push to the Limit on Purpose, Not by Default
Every session should push you to your limit at some point. I always program a finisher at the end, something that tests grit and reinforces the fighter’s identity. You need to know you can go there when it counts. In a typical four-week training block, the high week is where most sessions push the limit. The other weeks vary the intensity.
Pushing on purpose isn’t the same as pushing by default. My default was to push every time, it’s one of the hardest Muay Thai training mistakes to acknowledge, and it cost me. The session finisher is intentional, and prescribed. You choose it, you smash it, you recover from it. You don’t let it become the whole session, the whole week, the whole career. Most Muay Thai training mistakes start right there.
I won what turned out to be my last fight, but I was taken by ambulance to hospital immediately afterwards to spend the night under observation. Six hours after the fight, my resting heart rate was still 83 beats per minute. Normally it’s 45. My blood lactate was still 14 mmol/L. My body wasn’t recovering. It was under severe physiological stress. But I finished that fight, and I won it, because I’d conditioned myself physically and mentally to meet the challenge head-on. The same relentlessness that gets you through a finisher is the relentlessness that gets you through a fight where your body is failing you. It’s a weapon and a liability. The skill is knowing which one it is right now. Use it deliberately. Always respect it.
Further Resources
What to Watch Next
If you’re wondering how to actually apply that IPO model and figure out whether your constraint is in the input or the process, I’ve got a video that walks through exactly how to diagnose where your biggest gains are hiding.
Muay Thai Performance Series
- Part 3: Return to Training: Why Going Hard Guarantees You’ll Quit
- Part 4: The 4-Stage Muay Thai Training Program (Complete Blueprint)
- Part 5: Muay Thai Fitness: Why the Burn Destroys Your Cardio
- Part 6: 52-Week Training Plan for Fighters
- Part 7: Muay Thai Training Schedule: 3 Models That Actually Work
- Part 8: Strength Training for Muay Thai: Why Your Lifting Is Killing Your Fight Speed
- Part 9: The Complete Muay Thai Training System (And Why You’re Not Using It)
- Part 10: Muay Thai Strength and Conditioning Coach: Real-World Problem Solving
Building Advanced Foundations
- Strength & Conditioning for Muay Thai 101 — A science-based approach to accelerated athletic development
- Optimal Fight Camp Blueprint — Periodization strategies for peak performance

