One thing’s for sure, delayed onset muscle soreness is part of a fighter’s training – especially when you head out to Thailand to train!
But… Is delayed onset muscle soreness the sign of a good training session? How can you avoid being too sore? Should you train if you’re really sore? How can you reduce muscle soreness the quickest?
There’s quite a bit to unpack on this subject, so let’s get started!
by Don Heatrick
@donheatrick
Everything a fighter must know about delayed onset muscle soreness (aka DOMS)
Before we tackle why you get sore and what we can do about it, I want to jump right in and answer the question, “Is DOMS a bad thing? Or is it a sign of a good training session?”
The Good
We’ll start with what DOMS is good for. If you’re looking to gain some muscle mass, then it’s desirable to chase some mild muscle soreness as it shows you’re working at an intensity that will encourage muscle gain (muscle hypertrophy).
That said, most fighters aren’t looking to do this.
Rather than bodybuilding, we look to optimise power to weight ratio within a weight class. And that means focusing on better neuromuscular firing of the existing muscle fibres we have rather than creating bigger, bulkier (and slower) muscles.
I’ll link to an article explaining this in greater detail for you on the show notes page.
The Bad
The bad side of DOMS for a fighter, aside from feeling uncomfortable (and that may be understating it), is the negative effect it has on your subsequent training sessions.
You can expect varying degrees of strength loss, pain, muscle tenderness, stiffness, and swelling.
Strength loss usually peaks immediately after exercise or within the first 48 hours. Muscle forces can drop by as much as 60% and aren’t always fully restored until 8 to 10 days later.
Pain and tenderness peaks within 1 to 3 days after exercise and takes about 7 days to fully subside.
Stiffness and swelling peak within 3 to 4 days after exercise and typically takes 10 days to get back to normal.
As a fighting athlete, you can see how this isn’t going to help you train at your best or make the best progress in the week following an exercise bout that’s caused you significant DOMS.
Strength loss will not only prevent you performing strength actions to the best of your ability, but will also negatively affect power and speed output too.
Pain and tenderness will obviously affect the quality of your sparring – you’ll be more distracted by exaggerated discomfort when receiving blows. And your skilled movements will also be compromised too.
Stiffness and swelling will reduce your range of motion, further restricting your ability to move properly, and care must be taken not to practise and repeat poor skilled movements.
This is a prime consideration when learning new skills, because we know from motor pattern learning research that you can easily automate a bad habit with just 300 to 500 poorly performed reps, wiring in a poor movement ‘engram’. A bad habit that will take thousands of repetitions to correct! I’ll link to a video and article going into this for you on the show notes page with the episode.
Because fighters demand power, flexibility, and highly skilled movement, DOMS doesn’t indicate a good training session. Rather it’s something we should minimise while still chasing improved performance.
But how can we avoid excessive delayed onset muscle soreness in the first place, and how can we recover from it as quickly as possible when it does show up?
We’ll start by briefly exploring why you get sore in the first place?
Although research hasn’t nailed down exactly what’s going on when we feel pain and stiffness in muscles following unfamiliar exercise, we know that it tends to start within 6 to 8 hours, typically peaks between 2 to 3 days later, and follows a certain sequence of events…

First, there is mechanical damage to the skeletal muscle as a result of the exercise. This in turn sets off an inflammatory response and swelling, which then results in the sensation of pain.
Understanding this sequence allows us to tackle delayed onset muscle soreness using targeted methods at each stage. With the first stage representing opportunities to minimise or prevent delayed onset muscle soreness in the first place, and the second two stages opportunities to recover from DOMS quicker and minimise its effect.
First up, what causes mechanical damage?
We know that muscle soreness is the result of damage caused by doing something that you’re not used to. This could be suddenly increasing the amount of an exercise (more time, sets and reps), or performing a new movement through a different range of motion.
We also know that eccentric (lengthening) muscle actions – like when you lower a weight – are responsible for the soreness, not the concentric (shortening) actions – like when you lift a weight. And that isometric (bracing, holding) muscle actions sit somewhere in the middle.
Exercises that cause eccentric actions are the ones that will make you the most sore. Things like lowering a weight as I’ve said, running down hill, stopping and turning in shuttle runs, or landing from jumps.
Secondary to this, isometric actions can also hit you fairly hard. Things like holding static holds at the bottom of a push up or the top of a chin up, bracing the core on an ab rollout, or resisting your head being pulled down in the clinch
Whereas concentric muscle actions aren’t responsible for the soreness. Things like lifting a weight, running, jumping up, or throwing punches and kicks.
Delayed onset muscle soreness doesn’t just strike those that are “unfit”, rather it affects those that are “unprepared” for a specific quantity or type of exercise.
I mentioned in a previous video that a 5 min shuttle-run fitness-test in the morning, caused elite Thai Muay Thai fighters a lot of DOMS in their legs by the afternoon session. The stopping and turning at each end of the shuttle caused eccentric muscle actions, and turned out to be an unfamiliar loading too!
Minimising Mechanical Damage
Our first priority is to prevent mechanical damage as much as possible. No damage, no DOMS! However, for training to be progressive and continue to make you a better fighter, your training stimulus must evolve over time and become more demanding.
Any time you introduce something new to your training, there’s a strong chance you’ll experience some DOMS initially. But to make sure it’s minimal, here are my recommendations:
Training Intensity and Quantity
Start small and don’t jump steps. Introduce any potentially new exercise or training method at a lower intensity and with a smaller training volume (that’s duration, or number of sets and reps). If you suddenly double the length of time that you train, distance that you run, or intensity, you’ll get sore.
Fighters new to resistance training should certainly be mindful of progressively adding this mode of training to their program in manageable increments. Increases in training volume of no greater than 20% each week will allow for sufficient adaptation.
Not only will this help prevent DOMS, but progressive overload is also the cornerstone of effective long-term athletic development. Just because you can, doesn’t mean you should! Don’t be tempted to skip steps that will improve your performance and prevent you prematurely hitting a glass ceiling or performance plateau.
Watch The Eccentrics
Keep an eye on how many eccentric, yielding movements you have in your training program – such as slowly lowering a weight, running down hill, landing from jumps. Understand that these movements, even in small doses, will potentially cause the most soreness.
Use Full Range of Motion
Working a muscle too hard in an unfamiliar range of motion will also cause soreness. To protect against that, progressively program exercises that use a full range of motion to keep the body prepared. And of course your mobility will be greatly improved too!
Exploit Repeated Bout Effect
The only proven method of protecting against DOMS and preventing exercise-induced damage is to perform a prior bout of similar eccentric contractions at a lower intensity. This method is known as repeated bout effect or RBE, and appears to last for weeks as opposed to days. However, it’s important to emphasise that the RBE only transfers to subsequent bouts of exercise if it’s extremely similar to the initial bout.
Research has also found that an initial bout of eccentric exercise of less than 10% of the volume of the subsequent bout is enough to reduce DOMS and promote faster recovery due to RBE, even up to 2-weeks later.
Therefore to benefit from the protection of the repeated bout effect, it’s not necessary to perform a high number of eccentric muscle actions. However, as well as the number of eccentric actions it’s also important to consider the range of motion to create an effective RBE.
And if you’re looking to introduce a new exercise or activity into your training program, consider adding similar movements to your warm up in the preceding week or two. Even using just one lighter set can stop you getting sore when you hit that movement for real in the next training block.
For example, even just one set of 10 push ups this week will help minimise DOMS you could experience from doing 10 sets of 10 push ups (100 reps) next week.
Simply pre-training specific muscle groups provides better protection from future more severe training. And this should also be considered when a fighter returns from a lay off from training too.
Adequate Warm Up
In a similar vein, pre-exercise warm up has been shown to be effective in reducing DOMS while incidentally cool downs don’t reduce soreness. So make sure you’re extra thorough with your progressive warm up in sessions introducing new exercises or training variations that could potentially cause mechanical muscle damage.
Adequate Training Frequency
Sporadically hitting the body with a novel training stimulus isn’t going to help you stave off muscle damage and resulting muscle soreness! If, despite loading progressively, the same exercise activity continually makes you sore, your training frequency is likely too low – you must train it more often.
Also along these lines, consider keeping your exercise selection more consistent as you move through subsequent training blocks. By swapping out only key exercises, and maintaining consistency with others (while of course changing intensity, sets and reps to match the focus of the training block), you can better protect yourself against DOMS too.
Recovering From Delayed Onset Muscle Soreness
Moving on from the mechanical damage stage of DOMS, where the emphasis is on preventing soreness, let’s now take a closer look at both the inflammation and swelling, and pain stages which will help you recover from and treat DOMS once you have it!
Active recovery strategies are preferred to passive ones to remove waste products in the blood, increase pain free range of motion, increase muscle performance and strength, increase tolerance to pain from pressure on the muscles, produce higher total quality recovery, and reduce the feeling of heavy legs.
Active recovery contributes to both physiological and psychological benefits for a fighter and a greater motivation to train. In short, we want to keep you moving!
In fact, it’s worth pointing out here that further exercise won’t adversely affect soreness. It can only help!
However, it’s also true that anything you do will only temporarily reduce soreness through exercise induced analgesia. The emphasis is on keeping moving.
This pain reducing analgesic effect is produced in two ways:
- Light to moderate localised concentric, shortening muscle movements result in exercise induced analgesia in the those working muscles
- Light aerobic exercise (60% to 70% of max heart rate) creates a general exercise induced analgesia throughout the entire body

So let’s look at the best performing recovery strategies:
Jogging and steady running are effective choices as they combine both localised muscle contractions and general aerobic heart rate demands to create the analgesic pain reducing effect.
Even better, light swimming or aqua exercise combines light concentric only exercise, aerobic exercise, AND a hydro massaging effect. The water resistance means there are no eccentric muscle actions at all. I’d have to say, if you’ve managed to cripple yourself with DOMS, getting in the pool would be my best recommendation.
But for me, the gold standard for fighters looking to recover from DOMS is without a doubt shadow boxing! It typically reduces pain by about 40-45%. You’ll benefit from the analgesic effects of both local muscle contractions all over the body and general aerobic contribution, AND you’ll bank some skill specific practice. Which will sharpen up your movement time and overall response time as a fighter.
I love a two for one deal! And research using a Wii Sports Boxing Active Game shows 20 mins of aerobic boxing outperforms 20 mins of either ice therapy or regular light resistance exercise in reducing DOMS.
Speaking of ice therapy, although it does regulate inflammation and decrease DOMS symptoms from day 1 to 2, I see it as a ‘nice to have’ in addition to light exercise like shadow boxing, swimming or running. Because it demands extra time and is something fighters could also find less appealing.
If you have time, I recommend cold water immersion as part of your weekly practice. Not just to reduce inflammation and muscle soreness, but for psychological training of determination and grit. But that’s a topic for another time.
Another mode of exercise shown to reduce DOMS is regular yoga – interestingly where static or dynamic stretching doesn’t! It seems there are other benefits to yoga over merely stretching that come into play, like a variety of physical postures, breathing techniques, and meditation.
Nutritional Strategies For DOMS Recovery
It’s also worth considering nutrition-based strategies to reduce inflammation and free radicals – those unstable atoms that can damage your cells as a result of intense training, illness or ageing.
We also need to consider what supplements the IOC (International Olympic Committee) recommend, especially now that Muay Thai has Olympic recognition.
And to be honest, right now, although some positive effects have been reported using supplements such as curcumin, tart cherry juice, beetroot juice, and quercetin, appropriate dose and durations haven’t been determined. And any benefit gained from these supplements is dwarfed by the physical interventions we’ve already discussed.
My advice would be to keep eating a range of healthy foods in correct proportions to ensure your body is fit for withstanding the strains of your training.
Make sure you’re consuming anything between 1.2g and 2g of protein per kg of body weight each day. That way you’re supporting the muscle repair and recovery process.
Regularly consume carbohydrates to replace the muscle glycogen lost during exercise, which was fuelling your muscle contractions. This will also help you spare your protein intake for recovery rather than refuelling.
And make sure you remain hydrated. That’s a simple way to reduce muscular pain, as muscles are a high percentage water, and even mild dehydration can make DOMS feel worse.
Treating Delayed Onset Muscle Soreness Pain
Finally, that leads us onto the final stage in the DOMS sequence, specifically, the pain. It seems anti-inflammatory drugs such as ibuprofen, diclofenac, or ketoprofen have shown some benefit in reducing soreness, but results are difficult to generalise.
For fighters, a massage with Thai boxing liniment before training can be helpful. Other than the massaging action itself providing some benefit, the analgesic effect of the oil itself can also help you move better in that session.
Final Points
And going full circle, consistent movement is key – quality movement at that. Don’t repeat poorly executed skilled movements that pollute your hard earned motor pattern engrams. And learning a new fighting technique or skill when movement is sabotaged by DOMS could quickly reinforce bad habits that’ll take thousands of repetitions to correct.

Also, do everything you can to plan your training not to cause undue mechanical damage in the first place by progressing training intensity and volume properly, avoiding excessive eccentric muscle actions, regularly using full ranges of motion, exploiting repeated bout effect, using progressive warm ups, and not going too long between training certain movements and intensities.
Coaches should make sure they distinguish between muscle strain and DOMS before prescribing exercise. And avoid programming training that develops maximum strength and power if a fighter is experiencing delayed onset muscle soreness in affected muscle groups, due to the drop in strength and range of motion.
It’s also recommended that coaches don’t introduce new eccentric movements, such as plyometrics, within 14 days of competition to prevent a fighter suffering from muscle damage that will impair their performance.
Fighters that must train on a daily basis should be encouraged to reduce intensity and duration of exercise for a day or two following intense DOMS-inducing exercise. Alternatively, exercises targeting less affected body parts will allow your sore bits to recover!
Above all, it’s good to train even if you have DOMS, don’t stop. And shadowboxing is more valuable than you probably realise!
Further Resources
- Muay Thai, Muscle Growth and Reps
- How To Get Good At Muay Thai Fast & Keep Getting Better & Better!
- Breaking Limits in Muay Thai
- How Do Thais Train So Much – And Why You Don’t Have To
- Why Your Progress Stalls – The Secret To Relentless Gains
- Strength & Conditioning for Muay Thai 101 – A Science-Based Approach to Accelerated Athletic Development
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/
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