by Don Heatrick
@donheatrick
Fat loss is a huge issue for Muay Thai enthusiasts of all levels.
Not just cutting weight temporarily for one fight, but a long-term change in body composition – losing all unnecessary fat, so the body has only what’s useful for the highest performance.
And of course, looking great is a most welcome side effect!
It’s an issue I’ve addressed for countless clients over the years, and in this guide, I’m going to give you the critical points so you can succeed too.
Keeping on top of these critical, basic points will mean you lose fat. These are the big things you must do.
If you’re not at least doing these things, then forget about adding anything extra to your fat loss tool box. They’ll be redundant, and you’ll be wasting time and effort.
And we’re looking for a lifelong change here – not a temporary fad that means you look good for a month, and then you’re back to square one, or worse.

The author, Don Heatrick’s body composition has remained largely consistent his whole life (aged 47 years)
As a former pro fighter myself (who at 47 years old, has maintained a sub 10% body fat level all my life), I know the importance of maintaining a competitive body fat level between one fight and the next.
If a significant portion of your nutrition and training between fights is focused on changing your body composition, less is focused specifically on improving your fight performance.
It’s not a trap we want to fall into.
In this simple guide, let’s get you where you want to be, and keep it there with consistent habits.
Fat Loss Isn’t Losing Weight
As a Muay Thai and strength and conditioning coach, you may expect that I’m focused on body weight goals for my clients. But I’m not.
I really don’t care what you weigh.
Apart from making weight for a fight, weighing scales aren’t a big player in my assessment of your progress. Too much is made of body weight, and it’s a liar for two reasons…
1. You’ve Likely Lost Water
I constantly hear tales of daily weight fluctuations on the scales… Which in reality are measurements of how hydrated you are.
Water is heavy, and most of your body weight (about 60%) is made up of it.
The amount of water you contain constantly fluctuates too – depending on how much fluid you’re taking on through food and drink, how much you’re losing through normal body functions (such as toilet visits and sweating), and foods you’ve eaten (more on that later).
Half a litre of water weighs about 0.5kg (1lb). So if you sweat off a litre during training, you’re a kilo (2lbs) lighter. This isn’t fat loss.
If you drink a glass of water, that’s an instant 0.25kg (0.55lbs) added on the scales — you’ve effectively become the container for that water. This isn’t fat (or muscle) gained.
Water weight loss is the fighter’s strategy for rapid, temporary weight loss in the final week before a fight. But this shouldn’t play any part in your general training goals.
2. You May Have Lost Muscle
Aside from the considerable effect of fluctuating onboard water, the weight you lost could also be muscle rather than fat.
Losing muscle is a huge no-no for anyone, especially fighters!
Unfortunately, some fighters and coaches don’t seem to differentiate… And it hurts fighters progress.
Lost muscle, is lost athletic performance (strength, power, speed, endurance), and reduced ability to burn calories (slower metabolism) – and therefore slower fat loss too.
When your metabolism drops, it’s even easier to overeat and put on extra body fat in the future – even if you’re eating less than you were before your “diet”.
As you lose muscle, you need fewer and fewer calories to maintain your dwindling body, and the easier it is to put on fat!
This cycle of weight loss (including muscle loss) followed by fat gain after cutting weight for a fight, is all too common. And simply because the goal wasn’t specific enough.
Specifically, you want to…
- Lose fat
- Keep (or increase) muscle
- Maintain (or improve) performance
- And who are we kidding… Look buff!
I’ll explain how you can achieve this in a moment. First, we need to measure where you’re starting from, so we know if you’re losing fat or not.
How To Measure Fat Loss
As a coach, I’m interested in your body composition (body fat percentage). This not only directly relates to your health, but also your athletic potential.
A lower body fat percentage means less dead-weight, and more potential for speed and power.
This is true at whatever level you compete, and becomes increasingly critical as your fight career progresses.
For elite performance, I’m ideally looking for male fighters to be under 10% body fat and females under 17%. In reaching these goals, you’re giving yourself the best chance of being competitive at the top level.
You’ll also be in true striking distance of your real fight weight, once you factor in safe pre-weigh-in water-weight-loss strategies.
To begin with, we need a benchmark… A measurement of where you’re starting from.
Body Fat Percentage?
There are several ways of measuring body fat percentage, such as skin-fold callipers, bioelectrical impedance scales, DEXA scans…
But in all honesty, in my experience, either the reliability of the measurement, or the cost of getting a scan, generally makes them impractical for most fighters. They’re a “nice to have”, and there are some other simple, yet effective ways to track your progress…

Mike sent me a couple of photos… One when he first started training with me, and another now, 9-years later – Mike has nailed long-term habits!
Begin With a Selfie
Before and after photos are a great way of tracking changes in body composition. Just look at Mike’s picture again, it confirms he’s lost body fat and increased his muscle mass too.
If you’re taking pictures deliberately for body composition tracking though, we should ensure it’s a fair, repeatable test…
- Wear the same (or very similar) clothing (or lack of clothing!)
- Use the same lighting, and the same colour background
- Don’t tense up your muscles
If you later want a photo in your favourite hulk-out pose for Instagram, that’s fine… But this one’s just for you to privately track your progress month by month. ;)
Next, using the following chart for visual reference, estimate your current body fat percentage…

Visual representation of various body fat percentages
The Tale of the Tape
Recording body dimensions with a tape measure is a good way to determine if you’re losing fat from problem areas (like the waist or thighs).
But these measurements must be done accurately…
Get yourself an anthropometric tape measure. It’ll not only be more accurate, but also a hell of a lot easier to do by yourself!

Anthropometric tape measure
Precisely describe your measurement sites so you can repeatedly re-measure at exactly the same spot, or you’re wasting your time.
For each site, generally re-measure a little higher and lower to find and record the largest dimension in that target region (such as neck, shoulders, upper arm, chest, waist, upper thigh, and calf).
Measure with your muscles relaxed to avoid introducing another variable. And check each measurement two or three times to make sure it’s repeatable too.
I recommend taking measurements every two weeks to track your progress.
Those Damn Scales
Despite everything I’ve just said about weighing scales, we’ll still take that measurement every one or two weeks!
But this is only to give us a rough idea of your potential rate of fat loss, and to track where you’re at in relation to making weight for an upcoming fight.
To make this weigh-in as repeatable as possible, do it first thing in the morning in minimal clothing, before eating or drinking anything, and after going to the toilet.
If you’re doing it right, you should be able to lose between 0.5–1kg (1–2lbs) of fat each week, without losing any muscle.
Whereas, it typically takes about a month to put on just 0.25kg (0.5lbs) of muscle! Muscle is hard earned and easily lost — keep it at all costs.
Weighing scales, used in combination with the other methods I’ve described, will give you a good idea of how your fat loss is going, and when you’ve hit your target.
Once you’re at a good body fat percentage for you, only then I’m truly interested in how much you weigh… And only with respect to which weight class you’re fighting in.
Does this weight class suit you and your fighting style?
To maintain this body weight, is too much of your performance training time wasted affecting body weight rather than becoming a better fighting athlete?
What To Eat & Drink For Fat Loss
When it comes to losing body fat, the most important thing is your nutrition. You can do everything else perfectly, but fail to get your nutrition right and not see any results.
Undereat Or Else
To lose fat you must undereat (be in a caloric deficit), burning more calories than you consume.
Everything you eat contains energy (calories). Every activity your body performs uses calories.
If you eat more than you use, you’ll gain weight.
Eat the same as you use, you’ll maintain the same weight.
Eat less than you use, you’ll lose weight… and we want that weight to be fat – definitely not muscle (more on that later).
To ensure your weight loss is fat, the first priority is to undereat by the correct amount. Over do it and you’ll lose muscle, under do it and you’ll not lose anything.

Undereating to lose body fat and rate of fat loss
How Much To Undereat
Undereating by between 500–1000 kcals per day will typically result in fat loss of between 0.5–1kg (1–2lbs) per week respectively.
Undereating by 1000 kcals each day will leave you hungry (and make recovering from training increasingly difficult). Whereas, undereating by 500 kcals each day is more manageable, easier to remain consistent with (forming a habit), and impacts your training/recovery less.
To undereat by 500 kcals daily intake, you have some options…
- Cut out junky snacks and alcohol
- Reduce your portion sizes for meals
- Swap poor food choices for lower calorie options or those that fill you up more
- Add more physical activity/training
And of course, you can do a little bit of all four!
For example…
- Stop having a chocolate Kit Kat bar as a snack: -240 kcals
- Eat 20% less for dinner (normally 500 kcals): -100 kcals
- Drinking water instead of orange juice at breakfast: -110 kcals
- Adding a 30 minute weight training session, or a steady 2 mile run for an 80kg (176lbs) fighter: -250 kcals
For a fighter who’s body weight hadn’t been changing on their existing diet and activity routine, this particular combination would have them undereating by a total of 700 kcals each day.
That should result in a fat loss of around 2.8kg (≈6lbs) in a month.
And this is without calculating how many calories you need each day (including physical activity), or tracking everything that you’re eating and then adjusting to eat between 500 to 1000 kcals under the calculated calorie requirement…
I advise to begin with that you keep it much simpler like I’ve suggested. Then if you need to, go into detail if things aren’t working.
This guide is about a simple approach.
Are you currently putting on weight? If yes, under eat by 1000 kcals per day.
Is your weight currently stable? If yes, under eat by 500 kcals per day.
Both of these situations should result in a sustainable fat loss of about 0.5kg (1lb) per week.
And all you need to do is…
Total up the calories of the food you’re reducing, and/or the exercise or activity you’re adding on top.
To get an idea of how many calories your additional exercise is likely to be contributing, a heart rate monitor (with a chest strap) will do a good job of estimating calorie expenditure during training sessions.
How To Tweak Nutrients For Faster Fat Loss
After achieving the negative balance of calories-in versus calories-out for fat loss, the next priority is where these consumed calories come from.
More specifically, the amounts of macronutrients (protein, carbs, and fats) that you’re getting.
Exploiting Protein

Protein sources
Protein is found in meat, poultry, fish, eggs, dairy products (like milk, yoghurt and cheese), seeds and nuts, beans and legumes (like lentils and chickpeas), and soy products (like tofu).
You need it to repair and rebuild your body after training, keep your hormonal system working well, keep you feeling fuller between meals… AND you need it to preserve your muscle mass when you’re otherwise undereating to lose body fat.
You must keep your protein intake up.
If you’re only going to total up one more thing (other than how many calories your cutting out of your daily intake), then adding up how much daily protein you’re getting is the thing!
When undereating to lose fat, I like fighters to consume between 1.5g and 2g per kg of body weight.
That would mean an 80kg (176lb) fighter would need between 120-160g of protein each day.
Depending on your size, ideally you should aim for 20g to 30g of protein with every meal or snack – this will help with your recovery between training sessions, maintain your lean muscle mass, and fast-track your progress.
To get an idea if you’re hitting this daily protein target…
1. Total up the protein quantity on anything you eat that comes in a packet… look at the amount contained “per serving” on the label.
2. Estimate the quantity you’re likely to be getting in the whole foods (such as meat, poultry, fish, eggs, etc) you’re eating too.
Use the following tables to give you an idea…

Animal based protein | Sources: USDA FoodData Central (USDA), Tesco product labels, (T) MyProtein product labels (MP)

Plant based protein | Sources:
USDA FoodData Central (USDA), Tesco product labels, (T) MyProtein product labels (MP)
The trick here is to keep your protein intake up (to help hold onto muscle), but your calories down (to lose fat).
If you’re falling short of daily protein, use the tables to pick foods with a higher percentage of their calories coming from protein… those toward the top of each table.
For example, eating a small 96 kcal portion of shrimps or prawns will give you a whopping 22.7g of protein… About 95% of the calories you eat are protein!
Compare that to a 72 kcal pork sausage which provides a measly 3.9g of protein… Only about 21% of the calories are protein.
Whereas if you ate just 35 kcal of cooked mushrooms, you’d get 3.9g of protein too… But with half the calories of a pork sausage – because 45% of a mushrooms calories are protein.
Choosing the lowest calorie, highest protein options on my tables will seriously impact the quantity of protein you can get at a lower calorie cost.
Complete Protein & Plant-Based Protein
As well as protein quantity, we need to make sure that the quality is right too.
Proteins are made up of amino acid building blocks. Your body can make 12 of the aminos it needs by itself (non-essential amino acids). We don’t need to eat them.
But we need to get 8 other essential amino acids from food, as we can’t make them ourselves.
All animal sources of protein contain “complete protein” – it has all the amino acids. Whereas the vast majority of plant sources of protein are incomplete, containing some essential aminos, but not all of them.
Plant sources of complete protein are limited to quinoa, buckwheat, hemp seeds, chia seeds, and spirulina. Although, this isn’t a big deal, even if you’re sticking to a vegan diet…
As long as you mix-and-match your plant-based protein sources correctly, you can plug together two incomplete protein sources and get all the essential amino acids you need.
Pairing incomplete protein in beans and legumes, with the protein from either grains, or nuts and seeds, gives you a complete set of amino acids.
As long as you mix these protein sources in each day, your body will piece the aminos together…
But, if you do this in one meal it keeps things balanced and tidy. Here are some plant-based complete protein meal combinations…
- Beans on toast
- Corn and beans
- Hummus and pita bread
- Nut butter on whole grain bread
- Pasta with beans
- Rice and peas, beans or lentils
- Split pea soup with whole grain or seeded crackers or bread
- Tortillas with refried beans
- Stir-fry or steamed veg with rice noodles & cashew nuts
- Chickpea hummus on rye cracker
- Veggie burgers on bread
Even if you are eating animal-based foods in your diet, you can seriously boost your protein intake by also eating great vegetable protein sources too.
If despite looking at everything you’re eating, and switching foods to those with a higher percentage of their calories from protein, you’re still unable to hit your daily protein quota…
Or in doing so, your calorie count is still too high and you’re not losing fat… Then protein supplements can come to the rescue.
Go for protein “isolate” powders, because they’ll give you the most protein with the least calories.
Tuning Up Carbs

Carb sources
Carbohydrates are predominantly found in sweets, fruits, grains, and vegetables, and are the primary source of immediate energy for all of your body’s cells.
As a fighter, carbs can be a double edged sword…
It’s the perfect fuel for your rapid, explosive actions, and to keep you brain running well. But, it’s easy to make mistakes with your carb intake, that both messes with your body composition, and energy levels.
To understand how carbohydrates affect your fat loss, we first need to understand that not all carbs are created equal.
Once consumed, some carbs absorb into your bloodstream really quickly, and others take much longer.

glycemic index carbs on blood sugar and energy levels
High Glycemic Index (GI) carbs are absorbed quickly, spiking your blood sugar levels (sending you hyperglycemic), and medium to low GI carbs release more slowly, keeping a more stable blood sugar level between feeds.
When your blood sugar level spikes up, your energy levels do too. However, your body must bring your blood sugar back into control by releasing insulin – which brings you blood sugar levels back down quickly…
But it overshoots the mark, sending your blood sugar crashing below normal (hypoglycemic). You “crash” and feel tired, craving more High GI sugary foods to rocket your blood sugar up again.
And this cycle of “hyper” peak, then “hypo” crash will see-saw all day, along with your energy levels.
And this is also a problem when it comes to fat loss.
Peaking your blood sugar primes your body to hold onto its fat stores, preferring carbs for fuel instead. So fat loss is stalled.
Maintaining a stable blood sugar level by targeting carbohydrates that don’t digest as quickly allows you to both burn more fat for fuel (getting leaner), and use carbs as the high-octane fuel it is for explosive Muay Thai training.
These higher quality, slower-digesting carbs come from less-processed, whole foods with containing complex carbs and fibre, such as:
- Whole wheat breads, pastas, and flour
- Brown and wild rices
- Quinoa
- Potatoes
- Legumes, such as black beans, chickpeas, lentils
Lower quality, faster-digesting simple carbs to minimise or avoid include:
- Sweets/candy
- Biscuits/cookies
- Pastries and desserts
- Sweetened drinks, such as lemonade, coke or iced tea
- Energy drinks
- Ice cream
Use the following table to target carbs with a smaller effect on your blood sugar level (low and medium Glycemic Load).

Glycemic Load Tables
Bear in mind, these glycemic loads apply to the quantity consumed too. If you double the quantity, you’ll double the Glycemic Load (GL). And that could make a low GL food into a high one! Portion sizes matter.
One way to better control the effect even high GI carbs have on your blood sugar levels, is to eat them with some protein, fat, and/or fibre foods. This will slow down the digestion of the carbs, reducing the glycemic effect.
It’s not a coincidence that many of the plant-based carbs that are listed in the earlier Protein Sources tables don’t appear on Carbohydrate Sources tables.
This is because they score too low to even register as a low Glycemic Load carbohydrate.
Many of the best carbs for your fat loss are also the best plant-based protein sources too.
And if protein makes you feel fuller between meals as we’ve already established, consuming higher amounts of dietary fibre (a type of indigestible carbohydrate), helps you feel fuller during the meal. And you’ll be inclined to eat less.
If you want a simple eating for fat loss rule, it’s eat more protein and fibre.
Good sources of fibre are vegetables, fruit, lentils and beans.
Targeting plant-based protein for your meals, alongside animal protein sources too (if you’re not on a vegan diet) is the easiest way of achieving this.
Beware of Drinks
If you take a closer look at the Carbohydrate Sources table, you’ll notice that drinks effect your blood sugar levels… Particularly if your having more than one.
But even more critical to your fat loss goal, is that all these drinks add calories too. Calories that you then can’t eat (if your trying to remain in calorie deficit – the primary rule of fat loss).
If you want to drink some of your calories, that’s fine. Just remember it’s all part of your intake. And also realise that most drinks are carbohydrate rich rather than protein or nutrient rich.
Scoring daily carbs is way too easy, and scoring daily protein or nutrients is more difficult. Just make sure you understand where you are in relation to the first two objectives of fat loss nutrition – calorie deficit, and adequate protein – before excessively wasting calories on carbs.
And we also need to save some daily calories to eat some healthy fats too!
Optimising Fats

Fat sources
Fats are found in meat, fish, eggs, dairy, nuts, seeds, oils, cookies, cakes and some fruits.
Despite the fact that you want to lose body fat, it’s essential you consume fat in your diet!
Without it, you won’t make and balance hormones (particularly steroid hormones), your brain and nervous system will degenerate, and fat-soluble vitamins can’t be transported and used.
All of which not only makes you unhealthy, but also degrades your performance as an athlete.
However, fat is incredibly nutrient dense. It contains over twice the calories of either protein or carbs per gram.
If you’re to hit your undereating target, keep a watchful eye on the amount of fatty foods you’re consuming.
And when it comes to fat in your diet, there are “goodies” and “baddies”.
If we’re spending some of our limited daily calories consuming fat, we should steer towards the goodies as much as possible.
The truth is we thrive best on a balanced mixture of fat types. And to keep it super simple, this mix is simply achieved by eating a wide selection of whole, less processed food such as…
- Nuts and seeds
- Avacados
- Olives and extra virgin olive oil
- Dairy
- Eggs
- Poultry
- Game meats
- Beef, pork and lamb
- Fatty fish
The most important fats for health, athletic performance, and fat loss are omega-3 and omega-6 fatty acids… Because we must eat these – our bodies can’t make their own.
And between them, they balance effects, and do lots of useful things for a fighter such as…
- Reduce inflammation
- Reduce pain
- Open up blood vessels for efficient oxygen transport
- Open your airway
- Cause blood clotting and healing
You can get omega-3 and omega-6 by eating varied plant and animal foods, especially fatty fish and wild game meat.
You can avoid the dietary fat baddies such as trans fats, by avoiding industrially processed and refined foods like soyabean or corn oil. Fast food is typically a big offender.
Check the food labels for hydrogenated oils or fats, and steer well clear.
What About Alcohol?
For adults, alcohol is another potential source of calories – providing nearly twice as many calories per gram than protein or carbs. But, with very little nutritional value.
It’s another drink that can steal many of your daily calorie quota. Choose carefully.
And whenever alcohol is taken in, it’s the first fuel to burn – preventing your body fat being used for fuel, slowing up your fat loss.
Alcohol also somewhat impairs judgement… you’re far more likely to cave in and horse down a pizza after that third beer.
And honestly, if you’re fighting, it’s a good idea to wait to have a few drinks after the fight rather than the lead up to it.
Watch out for any habitual patterns of drinking – when triggered by stress for example… To successfully lose body fat you’ll need to recognise this and change things up (more on this later).
Quality & Quantity Foods

Eat a rainbow of coloured fruits and vegetables
Everything we’ve discussed so far addresses getting both the quality and the quantity of your food about right to support your fat loss goals.
If you’ve successfully applied everything mentioned so far, you should already be on a winner!
You’ll also get the micronutrients you need in your diet that I haven’t yet mentioned. So now I’m mentioning it…
We need vitamins and minerals in the right amounts, or we won’t function properly and likely get sick.
If you’re eating a good balance of different natural, unprocessed foods including plant-based sources, you’re unlikely to have any problems.
One thing I always look for in meals over the whole week, is to “eat a rainbow” – to eat as many different colours of fruit and vegetables as possible.
Different coloured fruit and veg contain different vitamins and minerals… if most of what you eat is always the same colour, then you’re probably missing out on something!
But something else to consider…
When eating more, you’re naturally getting more of the vitamins and minerals that you need for your body to function well.
However, when undereating for fat loss, you’re less likely to be getting enough of these raw materials to play with.
Therefore, you must make the best use of the calories you are taking in. Make sure they’re the best quality possible to keep you body running effectively, despite running on a reduced fuel supply.
If you’re worried you may be short on vitamins and minerals, then I recommend supplementing with a daily multivitamin and maybe a fish oil capsule.
Plating Up

Suggested starting point for meal portions
Use the following plate illustration to give you an idea of relative portions of protein, carbs, fats and high-fibre low-calorie vegetables in a general meal.
Depending on your size and calorie requirement, use larger or smaller plates to scale your calorie intake, depending on your rate of fat loss.
This is a starting point. Also adjust relative portions as required to suit you personally.
When To Eat
Timing is the next level of priority when it comes to nutrition for fat loss…
But if you’ve not yet sorted out your calories, protein, carbs, fats (from unprocessed natural food sources), then don’t bother worrying about timing.
Meal timing can help, but it’s less important than you may think.
For me, ideally athletes perform best and recover quickest when eating every 3 to 4 hours.
Your entire daily calorie intake is shared between 3 meals (breakfast, lunch, and dinner), and 2 or 3 snacks in between (optional evening snack).
Remember that every snack should provide some protein too. For example, an apple and some unsalted, unroasted nuts, or even a protein shake.

Suggested timing of meals and snacks for a Muay Thai fighter to promote good energy levels and recovery from training
What About Intermittent Fasting?
Going without meals for extended periods is another way to reduce your calorie intake and lose body fat.
And there are a number of benefits that fasting can afford you, ranging from reduced inflammation to better psychological control over hunger.
When I’ve experimented with intermittent fasting myself, feeling and understanding the difference between habitual, psychological hunger and real (body) hunger, was the greatest benefit.
But fasting isn’t for everyone. And I’d even say it’s not for most people…
Women have a more sensitive hormonal system that can easily get thrown out of wack – the majority of females won’t do well when fasting.
If you have a history of disordered eating, are chronically stressed, or not sleeping well, then fasting is not for you. If you’re new to either diet or exercise, or combining the two, I’d give it a miss as well.
It’s also not ideal for athletes who are competing… Nutrients simply aren’t on hand at the most effective times to promote recovery.
Once you’ve squeezed all the fat loss you can from the simple methods described in this guide, then intermittent fasting may well serve you well. But don’t start there.
Eating Things That Change Water Weight
I mentioned that your body weight on the scales is susceptible to fluctuations in water weight.
It’s worth highlighting that there are two main things that nutritionally can distort your water weight…
- Higher levels of sodium (salt) intake can increase the amount of water you’re carrying, making you heavier (not fatter).
- Low carb intake will reduce the amount of water you’re carrying, making you lighter (not less fat).
Be aware that variations in carb and salt intake can end up masking what’s really happening to your body composition.
How To Train For Fat Loss
I can’t stress how important your diet and nutrition is to fat loss. Exercise will accelerate the effects of your diet, but it can’t outwork a poor nutrition.
Fat loss is largely the result of what you do in the kitchen, not your training.
Your training boosts fat loss, ensures you don’t lose athletic performance, reduces injury risk, and hones the shape of your body underneath your fat layer.
For fat loss, exercise is favourable, but diet is critical.
That said…
Make Resistance Training A Priority
I’ve utilised weight training all of my life, with the objective of enhancing my athletic performance…
But along with a sensible diet, I believe this has also been my secret weapon in achieving a consistent body composition every year – for now over 47 years.
Hands down, resistance training sessions are the most important training for a fighter to lose body fat and keep it off. You need two, or maybe three of these each week.
The reason isn’t that these sessions will burn the most calories as you’re doing them, rather it will help preserve your lean muscle mass while you are undereating (especially if you’re hitting your protein targets too). Remember, losing muscle is to be avoided at all costs.
Your muscle mass is responsible for burning calories every second of the day, regardless if you’re awake or asleep. It’s crucial you keep this rate of burn up, and losing muscle kills this off – along with your strength, power, speed, and endurance.
As a worked example…

Comparing calorie expenditure of two fighters of the same weight
If we compare two 80kg (176lbs) fighters, one at 7% body fat, the other at 20% body fat.
They’ll both burn a significantly different amount of calories each day… Even if they both just stayed in bed all day!
The lean fighter (7% body fat) has far more muscle on his body, which burns calories at a rate of 1900kcals per day… even if he did absolutely nothing!
The overweight fighter (20% body fat) has much less muscle for the same overall body weight (the rest is body fat), and burns calories at the rate of 1600kcals per day at complete rest.
That’s a 19% difference in the amount these two fighters need to eat every day just to maintain their body weight.
And this difference in calories burned is true during physical activity too.
For the same levels of exertion and duration of training, the lean fighter will burn 19% more calories than the overweight fighter.
This of course makes it far easier to lose body fat, and crucially, to prevent putting fat back on again in the future.
Increased exercise also does more than just increase your “calorie burn.” It changes how your body uses calories… Sending more toward muscle growth and less to your fat cells.
And losing fat makes doing body weight exercise easier – without having to get any stronger or fitter.
Chin ups, press ups, burpees, and body weight squats become far easier if you’re carrying less dead-weight.
Try holding a 10kg (22lb) dumbbell between your knees while doing a chin up… See how carrying that much fat affects what you can do… Shedding this makes all the difference!

Resistance training is the most important part of your training for fat loss
How To Use Resistance Training
Resistance training can overload your muscle tissue to an extent that it results in hypertrophy – muscle gain – in a way Muay Thai can’t.
Training for muscle gain while undereating (with adequate protein intake) will at least maintain the muscle mass you have. Rather than losing muscle along with some of your body fat too.
And the type of hypertrophy we want as a fighter is functional… That is, it results in a proportional strength increase.
And this is best achieved using compound, multi-joint exercises such as squats, deadlifts, bench press, shoulder press, rows, and chin ups etc. typically for 3-5 sets of 6–8 reps.
As well as loading your muscles to prevent losing lean mass while undereating, and inadvertently snuffing out your metabolism…
Weight training is an opportunity to balance out areas of weakness supporting the joints, to prevent injury, and set the foundation for improved athletic capability and Muay Thai performance.
If you need a routine to get started properly, you can run through my “Functional Strength & Hypertrophy Routine for Muay Thai Fighters” here.
Cardio Training Is Optional
Cardio training is another layer you can place on top of your resistance training and Muay Thai training, if you have time available.
To be honest, your Muay Thai training already serves this purpose in terms of calorie expenditure, so don’t feel you have to add more.
It’s more important you create a sustainable training plan that you can stick with, rather than one you can do for a week, and then it all falls over.

For fat loss, cardio training is optional for a Muay Thai fighter
How To Use Cardio Training
When it comes to cardio purely for fat loss — rather than specifically for a fight camp — I recommend a “Cardiac Output” session…
Slow, steady jogging, cycling, rowing, or shadowboxing continuously for between 30-60 minutes, between 1 to 3 times a week.
The key is to train at a steady pace for about 30-60mins at around 60-75% of your maximum heart rate…
That’s typically between 120 to 150bpm, or 3-5 out of 10 on a rate of perceived effort scale (RPE).
Rather than sticking to one exercise type for the whole 30-60 min session, you can set up a circuit, spending 5 mins on each continuously without rest.
This sort of gentle cardio is more restorative in nature (remember you’re undereating, and your body will find it harder to keep up).
It’s also an opportunity to increase your calorie expenditure through physical activity if required.
And just because the sessions are “easy”, it doesn’t mean they’re aren’t highly valuable…
This specific “Cardiac Output” session enhances your foundation aerobic capacity in a way that Muay Thai, or high intensity intervals can’t.
Your Training Week
To recap, in addition to your regular Muay Thai sessions, you’re also looking to complete two or three resistance training sessions, and between one to three cardio sessions.
To get the best out of your training time, it’s important to arrange your week to make it as effective as possible.
The objective is to both manage recovery (so you can maintain constant progress without burning out) and to avoid conflicting physiological adaptations that stall athletic development.

You will amplify the effects of your training by considering these best practices when scheduling your week
Scheduling training best practice…
- Leave at least 48 hours between consecutive resistance training sessions.
- If possible, train cardio or Muay Thai at least 3-hours away from resistance training.
- If either a cardio or a Muay Thai session must be trained back to back with a resistance training session, train the most important one first
- Generally, don’t do more than two different sessions back to back
- Each session should target a specific purpose, and only do just enough to make your body better at it, and that’s it. Be progressive.
- Regardless of your training or fight experience, always have at least one rest day each week to allow your body to recover.
- Long-term progress far exceeds the capability of unsustainable short-term thrashing
Typical training session durations…
- Muay Thai sessions are usually 60-90 mins
- Resistance training sessions are usually about 60-mins
- Cardio sessions are usually about 30-mins
Sessions can of course be longer or shorter than these, but these are typical session durations for best training effect.
Generally, going longer means you’re doing more than you need to (exceeding minimal dose), practicing fatigued form, and spoiling your recovery so your next training session becomes less effective.
And if you’re obsessed about adopting the Thailand training model with 2-3 hour training sessions, please see them for what they are; multiple sessions joined together (with recovery periods in between)… Cardio Session + Muay Thai Session + Strength/Conditioning Session
For simplicity, when structuring your week, block out 30-minute or 60-minute time slots for each session type in your weekly schedule.
Structuring your week…
Now you know how many sessions you’re looking to fit into each week and how long they are likely to be, let’s look at where they can practically go.
Generally, fighters have more flexibility over the placement of weekly resistance training and cardio sessions, whereas Muay Thai sessions are largely timetabled group sessions.
Using the following Weekly Training Schedule Template…
- Begin by listing any sessions HAVE to be on certain days and times
- Now where can you practically place your strength sessions to best effect?
- Where can you place any remaining Muay Thai sessions (if any)?
- Where can you place any remaining cardio conditioning sessions?
- Which days are you taking as rest days?
- Check that you’ve considered the scheduling best practice
- Not enough time? Can you get up earlier and fit some in before work or studies?
This is now your draft schedule, but life happens – don’t be too rigid!
If it’s not possible to place things exactly where you want them one week, just try to complete as many of the target number of sessions as you can.
Doing something is FAR better than nothing.
If one week you can’t fit all the sessions, prioritise the most important sessions and get those done, dropping the others. Then try to return to the full schedule as soon as it’s practical.
For fat loss, the training sessions fall into this priority order…
- Resistance training
- Muay Thai training
- Cardio training

Weekly Training Schedule Template
Where To Place Fat Loss in Your Fight Camp
Because during fat loss, nutritional resources will be relatively low (due to undereating), athletic development is naturally hindered.
Therefore, the best place for fat loss in a boxer’s fight camp is furthest from the fight.
Aggressively cutting body fat close to a fight will make for sub par athletic performance — unless that is, being overweight is the primary limiting factor.
Also, the “fat loss” resistance training objectives of functional strength and hypertrophy (muscle gain) — to preserve muscle mass…
And the “fat loss” cardio conditioning objectives of gentler aerobic power and aerobic power training — to better facilitate physical recovery while undereating…

Optimal fight camp overview
Both align with the goals of a Functional Strength training block from my Optimal Fight Camp Blueprint too.
Although the preceding Mobility & Movement block, and subsequent Explosive Power, or Maximum Speed blocks can also be run with a calorie deficit…
Favourably, both the fat loss training objectives, and the ideal proximity from the fight are properly matched in a typical Functional Strength block.
This is the place to charge your most aggressive fat loss strategies.
Once your body fat levels are where you want them to be, you can stop undereating, and add those calories (and nutrients) back in again without gaining weight.
Scale up your portions by 500 to 1000 kcals (whatever you’ve been undereating by) so that your weight stabilises again.
At this point, with extra nutrients available, your performance will start to really take off.
How To Foster The Willpower For Fat Loss
Fat loss is simple, but it’s not easy.
It takes deliberate action, interrupting habits that have so far resulted in you gaining fat in the first place. Accept it’s going to take a big effort to do this.
It’s going to take willpower…
Which depending on how you “talk to yourself” about it, can either be a personal resource that depletes throughout the day as you use it, or one that strengthens the more you practice it.
Both are true, depending on how you view it. It’s a self-fulfilling prophecy.
To succeed, you must see willpower as something you strengthen with practice. And in a circular reference, this happens as you succeed at the tasks you set yourself.
This builds a willpower momentum.
I’m going to help you find this momentum now, and it all begins with honest reflecting on your habitual behaviours and taking full responsibility for them.
Nobody is perfect, and the sooner you recognise when it is you lead yourself astray, the quicker you’ll succeed. In anything!
Notice I say “lead yourself astray”.
Blaming situations, other people, genetics, or anything else that flashes up in defense of your ego, are all really scapegoats.
The truth is it’s how you choose to react to them that either makes you succeed or fail. In a nutshell, you need to become mindful…
Become effective at observing yourself independently, without judgement.
Ignoring or hiding the reasons we fail only reinforces more failure. If something hasn’t been working, accept there’s a habit (that isn’t serving us) that needs to be broken.
If fat loss is an important goal for you right now, I’m going to help you take full responsibility and break poor patterns.
Here are some crucial ways to help you achieve the fat loss you want, and to keep it off…
1. Recognise life patterns when you feel driven to binge or eat badly
The vital, first step is to catch yourself in the act. When you find yourself about to binge on something you know isn’t going to help your fat loss goals, stop. Ask yourself…
Why are you eating? Are you eating when you’re truly physically hungry?
For example, are you “rewarding yourself” in response to a difficult day?
Try and recognise the life patterns that kicks off the binging habit.
It could be people that you are with, places you’ve gone to, a personal circumstance that has cropped up. There will be a trigger.
A trigger that creates an emotional response, that we attempt to appease with a binge!
Noticing the trigger and the habitual emotional cascade allows you to do something about the binge before it builds its own momentum.
When it comes to changing habits…
Put more steps between you and the things you don’t want to happen, and less steps between you and what you do want to happen.
For example, if you find yourself reaching for a chocolate bar at the end of a tough day, don’t buy them and have them sat there in the cupboard.
If you need to go out and buy one, you’re less likely to give in.
Have some fruit easily accessible instead. So you can make a more nutritious choice – if you really feel you need to eat something.
And try reframing challenging moments…
What successes have I already achieved? How can I draw energy from those?
2. Change one thing at a time
When it comes to changing habits, make incremental steps – don’t change everything at once.
Taking an all or nothing approach will inevitably lead to failure.
Become motivated by the positive – the achievements you’ve made, the delicious options you have. Rather than focusing on negatives such as what you can’t eat or drink.
Success leads to stronger willpower.
Giving yourself manageable (one at a time) steps allows you to check them off, and build willpower momentum.
Recognise and acknowledge when you’ve been successful (building willpower momentum).
Give yourself a pat on the back!
Tell yourself that everytime you work on a challenging task you become more capable of smashing the next one.
3. Create an action plan
Without an action plan, you haven’t decided what you’re going to do next.
Like Benjamin Franklin said, “If you fail to plan, you are planning to fail.”
But don’t become overwhelmed. This plan can be as simple as the one thing that you are going to commit to for the next 3 days.
Decide what this is and see it through. Then move onto the next one thing.
Consistently build up these actions and you will succeed.
For example…
- If you recognise you routinely binge eat later in the evening, decide to stop eating anything after 7pm.
- If you eat far too quickly (meaning you eat far more calories before feeling full), decide to slow down when eating meals. Be more mindful of the flavours and textures, using a minimum number of chews per bite.
- If you tend to buy something processed and unhealthy from the store at lunch time, prepare your meals ahead of time. Limit your options to conserve willpower.
- If you tend to react badly to stressful situations, look at ways to reduce stress and build self-efficacy, such as meditation, and getting more high-quality sleep.
So that you can steer through the general actions that’ll have the greatest impact on your fat loss, I’ve presented summary bullet points in a useful, priority order at the end of this guide.
4. Expect progress it be erratic, not a straight line
As we’ve already discussed, your weight on the scales will fluctuate daily, even weekly… but the trend over a month should be in the direction we want.
And when it comes to forming stable, life changing habits…
We must understand that on average, it takes more than 2 months before a new behavior becomes automatic.
And realise that the closer you get to your ideal body fat percentage, the harder it is to lose fat.
There will be good days and bad days, but don’t let that deter you from your goal. Shake it off, refocus, remind yourself what you’ve already achieved.
5. Strive for consistent, not perfect
It’s impossible to perfectly adhere to everything all of the time, and it’s unnecessary – prioritise the critical things.
Being consistent far outperforms being perfect for brief spells, and then falling off the wagon.
Be aware that some habits compound, making it easier to remain consistent.
For example…
Regular exercise fuels the desire to improve nutrition too.
Getting your training gear out the night before makes it easier to see through that morning exercise session.
Once you reach your body fat percentage goal, adjust your diet again sooner rather than later if you notice a drift in the wrong direction.
Willpower is best used with a strong amount of honesty, self-compassion, positive self-talk, and social support.
6. Get accountability
If family and friends understand your personal goal, they can help you achieve it.
This goes beyond them helping remove unnecessary temptations and sabotaging situations, or even helping you celebrate successes (however small) along the way too.
It’s far easier to remain on track if you are accountable – if someone is expecting a report on how you’ve done.
Tell someone who supports you what your action plan is for the next week.
If you know that multiple people are expecting you to report back to them, you’ll get it done.
And if you have someone joining you on your quest, this helps too. If a training partner is expecting you to join them, you’re less likely to bail.
This accountability helps create consistency.
Closing Notes & Next Steps
First, here’s a quick reminder of the key points for fat loss.
Start by measuring…
- Take a selfie every 4 weeks
- Measure problem areas with a tape measure every 2 weeks
- Track weight on the weighing scales weekly
When it comes to food…
- Eat unprocessed, natural, whole foods
- Eat a rainbow of coloured fruit and veg
- Reduce portion sizes
- Aim for high protein (every meal and snack)
- Watch out for hidden calories in drinks
- Prioritise complex carbs (lower glycemic load)
- Watch the fat intake from poor food sources
- Eat 3 meals and 2 or 3 snacks each day
- Consider taking a multivitamin & fish oil capsule
For training…
- Get in 2 or 3 resistance training sessions per week
- Focus on functional hypertrophy strength training
- Train Muay Thai as normal
- If possible, get 1 to 3 cardio sessions per week
- Get one rest day in each week
- Prioritise fat loss at the beginning of a fight camp not the end
Getting your head right…
- Take active responsibility and build willpower momentum
- Recognise life patterns that break your willpower
- Change one thing at a time
- Create an action plan
- Expect progress to be erratic
- Strive for consistency, not perfection
- Get accountability
Follow these recommendations for 8-12 weeks and see all the benefits for yourself, in both your physique and improved Muay Thai performance.
Done properly, you’ll have shed between 4kg to 12kg (8.8lbs to 26.5lbs) of fat – depending on the number of weeks you went for, and how aggressively you cut calories.
And above all, you should also have changed your habits forever, and your body composition forever too.
By cutting body fat without losing lean mass (possibly even gained some muscle), you not only look leaner, you perform better. And you’ve finally broken the cycle of ballooning in weight between fights.
Now your fight camp is spent improving fight performance, rather than cutting body fat… Progress is accelerating!
Further Resources
Now that you’ve addressed the body composition side of the equation, your next question is very likely, “Which Fight Weight Class Should I Fight At?”
I’ve written a complete guide for those that compete at any level, to calculate your ideal fight weight class, learn how to safely cut water weight to hit this weight, and learn how to eat and drink after weigh-in to reach peak performance. You can run through my What Is My Ideal Fight Weight Class? guide here.
Once you’ve stabilised your body composition, or simply want to jump ahead into building greater fight-specific movement patterns and strength, power, speed, and endurance – check out the Muay Thai S&C Accelerator.
Thanks for reading, I wish you the strongest start to your training this year and the best performance if you’re competing.
Don Heatrick
Founder of Heatrick Strength and Conditioning
Don Heatrick is a family man from the UK, former mechanical design engineer, European Muay Thai silver medallist, former pro Thai boxer (ranked 4th in UK while aged 40-years), a Muay Thai coach, podcast host, and the go-to expert on Muay Thai performance training with over 25 years of coaching experience.
Don helps ambitious fighters and coaches take their game to the next level by bridging the gap between Strength & Conditioning, Performance Science, and Muay Thai.
Follow Don Heatrick on Instagram: https://www.instagram.com/donheatrick/
A very complete guide! I am a Kyokushin fighter AND a bodybuilder. From my fighter point of view, I use bodybuilding to build and keep muscle mass for both goals. If I’m focussing on the fighter side of me, I will indeed choose the compound type of exercise rather than the isolation type of exercises. I will not call this functional type of exercises, but that is semantics. In general I find it difficult to define functional exercises more acurately, since doing a biceps curls, which is an isolation exercise, can have it’s benefit in daily life activities as well. So biceps curls can be functional type of exercise. Every muscle has it;s function, it is hard to name a muscle that is not functional.
Hi Sonny, I’m glad the guide has proven useful.
Semantics aside, the definition of “functional” exercise is useful to qualify exercises that will provide a greater transfer of training to a sport or activity.
And what is deemed functional depends on the physical activity that you’re applying it too.
Generally, exercises that isolate a single joint aren’t functional… the body coordinates the articulation of multiple joints and limbs to create a “functional movement”. One that improves not only strength, but also the coordinated pattern of motor pattern control to reinforce the body’s position, balance, and timing of the executed during the movement “skill”.
More on the foundation movements and stabilisation patterns in this guide here.
However, like I said it depends on the activity that you’re training for. For example, bicep curls may not be functional for Muay Thai (horizontal rows and vertical pulls are), but curls for example are functional for BJJ and MMA… To resist arm bars.
In fact, dynamic bicep curls are less functional than isometric exercises at a nearly fully-extended elbow position!
So to clarify functional exercise, move away from thinking about muscle groups (which will be your body building bias), and instead think of relevant movement patterns and body positions.
Hi Don,
thank you for this complete articel. Everything I knew about food in case of loosing weight you covered and even enlightened me on more things I didn’t know!
I have a question to you, that really botheres me.
I follow a meal plan and even weight my food for calories. Usually I am always hungry – I am one of the people that never can eat enough. So for me loosing weight is really tough.
But what do I do, if I get sick. I cannot make sport like in healthy times. How should I behave in times of sickness and how should I start afterwards to not loose muscle but also don’t build up too much fat?
And also, which kind of training I should start again according to your blueprint?
For example if I’m in the power block in 2nd week, just before the maximum effort week, where should I continue? Should I just continue from the beginning of the block or from a block before?
How is it when I just have a cold and am out for 2 weeks and how is it when I have corona and am out for 2 months?
Do you have any thoughts about it?
Greeting Lukas
Thanks Lukas, glad the article has been helpful.
If you get sick, first priority is to get well again as quickly as possible. So eat as well as you can (nutritious and high protein) and rest up.
Keeping intake protein up will help preserve muscle mass, but if that is a concern on your return to training, then begin with a strength and hypertrophy training block.
Otherwise, restart wherever feels right. If you had just started the Power Block but not completed it, I’d rerun the block from the start again. This will allow a gentler start (beginning at low week again) and allow all the gains to be made by fully utilising this block.
Yes, you certainly can’t compare a cold to Corona in terms of the impact it will have on your fitness and training.
Your Resources are criminaly underrated, i knew about your Work for quite some time now but this article was so complete it blew my mind.
Thanks for the great Work, wishing you all the best with your undertakings.
Hope we can work together one day.
Greetings from Germany.
Cheers Paul! I really appreciate you saying. :)
This is a great, detailed article! It’s been challenging finding sources that discuss dieting while adding cardio, so this is extremely helpful to reference.
Thank you!!
Tiffany
Thanks Tiffany, glad you’ve found it so useful. :)
Hey Don, thank you so much for this awesome guide, I’ve definitely learned a lot and want to incorporate it into my daily life. I am 18 years old and weigh 154 lbs at a 6 feet height. I have a fairly lanky frame with long arms and legs. I would say going from these charts I have a body fat percentage of around 12-15%,I plan on losing weight until I’m around 10% and then start building lean muscle, since I want to start competing in the amateur muay thai scene. My question is do you think it’s worth it to lose these last few percentages or should I just start building muscle from here on and I will automatically start losing this excess weight? I apologize if this is a dumb question, but I’d be very grateful if you could help me out.
Greetings from Europe,
Daniel
Hi Daniel, thank you for reaching out and sharing your goals there. And good question!
I’d suggest that you target the lean muscle gain, and you’ll find this will also improve your body fat percentage too. And, once you’re happier with the lean mass you’ve gained, you’ll find it easier to cut the fat afterwards – because your metabolic rate will have gone up too.
Best regards,
Don