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Social science is a ‘fuzzy field’ unlike the ‘hard’ sciences like chemistry and physics. As a result,
people often rely on their intuitions or introspection and they are strongly disinclined to use
evidence-based decision making. The lack of evidence-based reasoning for psychological issues
is ironic, because the psychological literature is extremely large. It vastly exceeds the combined
fields of nutrition and exercise science. So let’s use this knowledge to help our clients. Because
as it turns out, many strategies employed by coaches may well be working adversely.
Beware of the Pygmalion Effect
Menno has a reputation for being hardcore with his clients, at least the ones that are in it for
maximum results. “Many personal trainers learn my methods and tell me ‘That’s cool and it
obviously works like hell, but I could never do that with my clients.’ And so they never do. This
is telling of a paternalistic approach to coaching where the coach decides in advance if someone
is mentally weak or strong.”
Why is this a bad thing? For one, you could be wrong and then you needlessly compromise
your client’s results. Even worse though, you could be right. When you treat someone as weak,
they become weak. This is called the Pygmalion Effect in psychology. It’s a self-fulfilling
prophecy. When you treat someone as unsuccessful, even if entirely subconsciously, it lowers
their expectations and it influences their self-image. This makes them feel weak. And no one
becomes strong by feeling weak.
For example, the popular trend of ‘fat acceptance’ has been shown in research to cause people
to eat more and live a less healthy lifestyle. Treat people as weak individuals that realistically
have no chance but to be fat and fat they will be.
In psychological jargon, making people feel at the mercy of their diet and other environmental
factors externalizes their locus of control. Your ‘locus’ or place of control can be internal or
external. An internal locus of control means you operate under the belief that you have the
ability to control your environment. An external locus of control means you operate under the
belief that the outcomes of your life are largely the result of your environment with you having
little influence on them.
Unsurprisingly, decades of psychological research show that people with an internal locus of
control have higher levels of self-efficacy and are more successfull in achieving their goals and
improving their well-being than people with an external locus of control.
Moreover, fostering an internal locus of control can improve not just your actions but also your
perceptions and your motivation level. Take, for example, the media. In today’s self-victimizing
society, it is common to blame the media for, well, everything. More specifically and relevant
for us, the media is often blamed for making women have body image issues. As it turns out,
only women with an external locus of control perceive slim models as emotionally damaging.
Women with an internal locus of control instead view slim models as motivational. So if you’re
the type of person that sees a selfie of a good physique on Instagram and immediately starting
hating, it’s time to take a long, hard look in the mirror instead of the monitor.
In essence, the Pygmalion Effect is basically a form of the nocebo effect you learned about in the
course topic on carbohydrates. It’s an illusory negative mental effect that then causes truly
negative physiological effects. Failure of the mind leaking over into the body.
Another form of nocebo is Medical Students’ Disease. Learning about a disease or pathology
can make you think you have it even if you don’t, because most symptoms are vague and
ambiguous. Lacking energy? Adrenal fatigue! Or maybe you just didn’t sleep well? Don’t have
much libido? Low testosterone! Or maybe it’s just stress?
While medical students’ disease generally doesn’t result in actually seeking medical attention,
which would be quite extreme, it is still a significant form of nocebo and we see it all the time in
fitness circles, especially the functional training crowd. It seems everyone has anterior pelvic tilt,
muscles that aren’t firing, a structural imbalance and flexibility problems. Even if they don’t have
any symptoms. No pain, no movement limitations, just people that love to be told there’s
something wrong with them. It’s a perfect marketing strategy. You create a fictional problem
and then ask for money to solve it. (BioSignature, anyone?)
Another example of a nocebo/Pygmalion Effect is the typical physical therapist that’s afraid of
heavy weights. His or her prescription for any kind of injury is to avoid lifting weights. This fear
of movement actually decreases the amount of weight their clients can lift by 20-45%,
depending on how much the clients bought into the fear mongering. A physical therapist can
thus easily nocebo a powerlifter without any serious injury into losing his or her next
So how do we avoid the Pygmalion Effect and other forms of nocebo? Treat your clients as
champions, not your children. Economists work under the assumption that people are rational
until proven otherwise. Innocent until proven guilty. If there’s one keyword that summarizes
Menno’s approach to client compliance it’s this: empowerment. Here are some examples of
empowerment. There will be several more throughout the rest of this course document.
Don’t compromise greatly on optimal program design in advance because you think
compliance will be a problem.
Trust your client. If they say they can train 6x per week, have them train 6x per week
until they’ve shown it’s not working. Don’t induce the Pygmalion Effect.
If your client is starting a ketogenic diet, don’t tell them about the keto flu. You’ll just
induce Medical Students’ Disease. Only mention it if they get it to reassure them it’s
normal and it will pass in a matter of days.
Have your clients weigh themselves every day. Many coaches shy away from this
because it’s deemed to be ‘too burdensome’. Even worse than the fact you’re throwing
away highly valuable data is that you are A) discouraging the formation of habits and B)
removing a moment of diet feedback. Frequent weigh-ins are significantly correlated
with weight loss compliance [2]. Weight monitoring should be a form of control, not a
The burden of responsibility
Finally, as a coach, you should realize that empowerment goes both ways. You have to not only
empower your client. You also have to accept an internal locus of control over your client’s
compliance to the program. Many coaches see the adherence of their clients to their programs
as something that is largely out of their control. They see themselves purely as instructors: if
the client doesn’t follow the instructions, that’s not the coach’s problem.
In reality, based on the nocebo effect, empowerment and the Pygmalion effect that we’ve
discussed so far in this topic, you should now understand that as a coach you in fact have great
control over your clients’ compliance.
The flesh is strong, but the mind is weak
For many people, what you’re about to read is going to be like taking the red pill and finding
out you’re living in the Matrix. It is the very foundation of Menno’s coaching strategy of client
compliance and the use of empowerment.
[insert Hans Zimmer orchestra with ominous drums in the background]
Being in an energy deficit has practically no effects on your mental performance or your mood.
That’s right, all this feeling weak, the weird food cravings, the fatigue, being moody, it’s all in
your mind, at least probably until you’re venturing close to your essential body fat levels, like
during contest prep.
Lieberman et al. (2008) were the first to show with confidence that dieting is all in your mind.
They took a group of healthy individuals and gave them foods modified with special gels to eat
that allowed the researchers to greatly manipulate the energy content of the food without
altering the physical appearance, taste or texture of the food. The study subjects were then
given either 2294 or only 313 calories to eat for 2 days straight. The researchers unleashed a
whole battery of cognitive, physiological and psychological tests on the subjects. These tests
have been shown to be sensitive to detect the relatively subtle changes induced by caffeine use,
anti-histamines and cold stress.
As predicted, the subjects were hungrier when eating next to nothing, yet their mood, sleep
quality and mental performance were entirely unaffected by the 2 days of practical starvation. In
fact, after the study the subjects were told about the study design and asked if they thought
they were in the starvation or the maintenance group. The subjects couldn’t tell.
Previous research had already found that Ramadan fasting does not impair brain functioning and
that it takes 24 hours of total food deprivation for mental performance to start suffering. And
this was more likely due to dehydration than an actual effect of the macronutrients. In fact,
some aspects of mental functioning improve after missing a meal. This makes perfect sense
from an evolutionary perspective. When you run out of food, you need to become active and
stay sharp to obtain new food. If you collapse whenever you venture out of walking distance
from a McDonald’s, your genes don’t stand a very good chance of making it to the next
Other research confirms that when you’re sleeping enough, energy intake does not affect sleep
In another study, non-obese individuals in a 40% energy deficit experienced an initial dip in their
mood during the transition from maintenance, but in the subsequent weeks there was no
longer any effect on mood, sleep quality or mental performance compared to when eating a
maintenance diet. And yes, they were exercising 3-4x a week. In fact, 10% of the deficit was
achieved by increasing the amount of exercise they did. The subjects were in a metabolic ward,
so the diets were 100% controlled. And this is the key. When you’re not concerned (read:
obsessed) with ‘being on a diet’, you may notice the shift from maintenance to a 40% energy
deficit, especially because you have to do more exercise, but that’s all you notice: the transition.
Soon the diet becomes normal again and as a result you feel normal again.
You may be wondering about more long term effects in lean subjects undergoing intense
exercise. In soldiers, during a month long field exercise, being in a 40% deficit compared to a
14% deficit did not affect mood, psychological health or reaction time.
Moreover, a large body of research indicates that the body does not react to caloric intake per
se but rather uses contextual cues to estimate perceived food intake. When the energy density
of food is manipulated in research, unaware people still eat approximately the same amount of
total food volume and thus consume significantly fewer calories. Moreover, hunger, fullness,
desire to eat and prospective consumption ratings are the same, showing that you can be just as
satiated with less as long as you’re not obsessing over the fact that you’re restricting your
caloric intake. (See the course topic on ad libitum dieting for more information.)
To conclude, if you don’t focus on the fact that you’re dieting, you feel just fine. Pretty much all
the negative effects on how you feel and function are a nocebo effect. The negative effects on
how you feel are not due to your body suffering from the lack of nutrients: it’s all in the mind.
So the real culprit is not energy shortage per se. Hunger is the primary reason diets fail. Even a
seemingly psychological problem like binge eating is predicted well simply by hunger.
We will come back to this in great detail during the course topic on ad libitum dieting, but with
regard to compliance, it’s good to know that hunger itself is very much a psychological
phenomenon. Telling someone a food is healthy immediately makes them perceive the food as
less tasty. Not only that, but your perception of how many calories are in a food affects how
satiating it is. This nocebo effect even affects the behavior of the hunger hormone ghrelin,
showing that psychological problems can physically manifest themselves.
So how do we put all of the above into practice? It’s the same message as before. Don’t nocebo
your clients. Treat them as strong and they will become strong. Tell them they’re weak and
weak they will be.
Mental effects of the diet’s macronutrient composition
In several of the above studies the macronutrient ratio of the diet was also manipulated to
assess the effects on how you feel and mentally function. There was no effect in any of the
studies. This is in agreement with much of the literature that the macronutrient composition of
your diet will only have a slight, highly situational effect on your brain and mood if you’re
healthy [1, 2, 3].
But what about bloodsugar?
Green et al. (1997) have studied the effect of food deprivation – not allowing people to eat –
on how they felt and mentally functioned during a set of cognitive performance tests. Food
deprivation did not generally affect brain functioning with one exception: memory improved.
They also related glucose levels to cognitive performance: there was no relation. They
concluded: “...the brain is relatively invulnerable to short food deprivation.”
Blood sugar levels are tightly controlled within a narrow range in healthy individuals. The waves
of ‘spikes and crashes’ after meals are normally more like the gentle lapping of the sea at the
Brain food vs. postprandial somnolence
The whole idea that food gives you mental energy is misguided. It is based on 2 flawed
1. Food has energy, so surely it must give you mental energy. The problem here is
semantic: despite the similar words, mental energy and food energy are entirely different
concepts. Food energy is physical energy, akin to heat and movement. Mental energy
refers to cognitive functioning: how well the brain performs mental tasks.
2. People like food, so it’s easy to intuitively conclude you must function better after
having eaten.
In reality, rather than becoming more energetic after a meal, most people become sleepier. This
phenomenon is called postprandial somnolence. Postprandial means ‘after eating’. Somnolence
means ‘sleepiness’. From an evolutionary perspective this makes a lot of sense. Hunter gatherer
populations had to be wakeful and alert when food was scarce and could somewhat relax when
there was ample food available: “the neurophysiologic and metabolic mechanisms responsible
for the control of food-seeking behavior and the control of sleep and wakefulness are
coordinated so that hunger and vigilance are paired during the daylight hours, and satiety and
sleep are paired during darkness.” (Vanitallie, 2006).
The classic explanation for postprandial somnolence is that during digestion blood flow gets
shuttled to the digestive system with greater priority, leaving less blood available for the brain.
It was a plausible theory, but we now know it is wrong. Much like blood sugar, an abundance of
evidence shows the body strictly controls blood flow and oxygenation in the brain. Even when
exercising, your body mainains cerebral (brain) oxygenation. Turns out, the brain’s kinda
important, so if it didn’t get enough oxygen and blood whenever you eat, that would be no
Another explanation was that the feel-good-but-sedated neurotransmitter serotonin was
responsible for postprandial somnolence. The graphic below illustrates how carbohydrate rich
meals generally promote serotonin production, while protein rich meals decrease it. The
theory was that it’s thus specifically the carbohydrate content of the meal that influences
postprandial somnolence (‘carb knockout’). While it’s true that serotonin production is
generally higher following high carb, low protein meals, the macronutrient composition of a
meal does not reliably affect its resulting postprandial somnolence. (Except before bed, when
serotonin is further converted into melatonin and thus often promoting sleep onset: see the
course topic on sleep.)
The regulation of serotonin production. Serotonin production is increased following highly insulinogenic
(carbohydrate rich) meals (which cause muscle uptake of BCAAs competing for entry to the brain),
meals with a high trytophan content (the precursor for serotonin) and (low protein) meals with few
competing large neutral amino acids (like BCAAs and tyrosine). Source
The currently most well supported theory is that the central nervous system’s state is altered
by hunger. Hunger motivates you to become active and search for food via activation of the
sympathetic ‘fight or flight’ state, whereas satiety activates the parasympathetic ‘rest and digest’
state. Specifically, the hypothalamus - the area in your brain that controls vegetative functions
such as eating, sleeping, bowel function, sex etc. - senses satiety through the detection of blood
borne metabolites from foods, endogenous peptides from the gut and signals from the vagus
nerve, the biggest nerve of your parasympathetic nervous system. These signals of satiety can
stimulate sleep centers which results in postprandial somnolence.
The division of the central nervous system’s functions.
Satiety being the driving force of postprandial somnolence can why solid meals are more sleep
inducing than liquid meals. It also explains why larger meals generally result in greater
postprandial somnolence than smaller meals.
The best macros for compliance
As you learned in the course topics on the macros, there are clear benefits to consuming
enough fat in your diet and carbs are generally not essential to the point that they could
theoretically be omitted altogether in many cases.
However, most people know that it’s difficult to consume a fat based diet. They get hungry and
foggy and it’s difficult to create a viable meal plan with lots of fat and few carbs. So low carb
diets generally have poor compliance.
Actually, the above paragraph is complete and utter nonsense. It’s a perfect example of poor
intuitions from people who either don’t know how to make proper food choices without
relying heavily on grains (*cough* Dutch people *cough*) or who have simply never actually
tried a high fat diet.
In fact, a systematic review with a total sample size of 1222 people found that low carb diets
have a significantly better attrition rate (fewer drop-outs) than low fat diets. The following
image shows the specific study results.
Percentage attrition rate in low-carbohydrate (white) and low-fat (black) diets reported in the literature.
A meta-analysis confirmed that low carb diets are easier to complete than low fat diets with a
70% vs. 57% success rate in favor of low carb, though at the 12 month measurement this
dropped to 62% vs. 54%.
Why? As we’ll learn in the topic on food choices, low carb dieting makes it easier to make
healthy food choices. A healthy body is a healthy mind and all. Low fat dieting also simply
doesn’t work as well in the long term anecdotally, as you’ve learned, and if there’s one thing
that benefits compliance it’s success.
Thus, for the sake of compliance, the evidence supports the use of diets with sufficient protein
and fat. The carb content per se does not seem to matter greatly. Very broadly speaking,
psychology and physiology converge in this regard. Again though, don’t ignore individual
variation. Some people unquestionably do better on high carb diets, both physically as well as
mentally, but on average low carb diets have better compliance than low fat diets.
Calorie cycling
Calorie cycling is a great example of coaches treating their clients as fragile children without
having any scientific basis for this. “Cut days are bad for compliance.” “My clients will never be
able to follow a PSMF.” Of course, some clients simply aren’t motivated to do anything and as
you’ve learned in the course topic on intermittent fasting, certain personality types and lifestyles
are more suited towards aggressive calorie cycling than others. However, the research is quite
clear that calorie cycling results in superior or equal compliance compared to diets with a
constant calorie intake. Calorie cycling results in greater adherence and higher diet satisfaction
[2] or at worst, the compliance rate is the same as with linear diets [2]. In fact, even complete
alternate day fasting has an excellent compliance record.
Why? People are willing to work for something that works. Short periods of aggressive fat loss
are well tolerated because they make you feel like you’re actually losing fat. And when things
get tough, bulk meals are only a day away. The main reason people lose motivation on a diet is
the constant drag, the feeling there’s no end in sight to the food restriction. Calorie cycling can
reduce this feeling of endlessness.
Calorie cycling also aligns well with our intuitions about reward. Eating a lot after your
workouts feels right for many people. You’ve ‘deserved’ the calories. This also provides an
incentive structure to go train in the first place. If you go train, you get to eat more. Many of
my clients tell me they sometimes do extra training days so that they get to eat more. That’s
not really the intent of the program, but I’d much rather have them do an extra training session
and lower their weekly deficit a little than to have them go on an uncontrolled binge.
From an evolutionary point of view, calorie cycling is a much more natural way to diet. Humans
evolved on calorie cycling diets, not meticulously controlled constant daily energy intakes.
Start big
Common wisdom tells us to ‘ease into a program’. Start small. Start with a moderate energy
intake and gradually reduce it throughout the cut. Gradually build up the training volume.
The opposite often works best. Start big. When clients come to you, in those first weeks
they’re highly motivated, or at least as motivated as they generally ever will be. Use that
motivation to show them their work pays off. People who lose a lot of fat in the first phase of
their diet have better long term results than people who use a more gradual diet strategy [2].
Starting big also reduces the perception of effort compared to starting small. This counterintuitive finding is explained by psychophysics, specifically range-frequency theory. This theory
explains how we perceive magnitude: how big something appears, how painful a set of squats is
or how much money $5 is. Without going into the mathematics, which are needlessly
complicated (but profoundly awesome if you’re interested in psychophysics), RFT shows that
we rate magnitudes as their rank order in a comparable reference set from our memory. The
key point is that we don’t perceive magnitude directly but rather we see it relative to our
reference set. So if you start with a moderate deficit or training volume and you progressively
increase it, every increase will be felt harshly, because it’s always the highest point in the
reference set. Whereas if you start big, things only get better. Importantly, the same total
amount of pain is perceived to be less if you start big compared to starting small.
Intuitively, starting small puts your client in the mindset that “It’s only ever going to get worse.”
whereas starting big uses the initially high motivation to achieve great results, making the rest of
the program seem relatively tolerable.
By the way, range-frequency theory also explains perfectly which level of muscularity and BMI
we prefer. How muscular or lean we find an individual depends on where that individual fits in
our mental reference set. For the average obese individual who has only obese friends, a
moderately overweight individual can appear slim. For someone neck deep in the bodybuilding
community, anyone without abs may appear fat and it may be hard to even tell the difference
between the different classifications of obesity.
There is a caveat to starting big. It specifically works for effortful tasks, not for behavioral
change. Coping with a severe diet or tolerating a high training volume are good examples
effortful tasks. The key here is to manipulate how difficult these things appear, not how to do
When it comes to more complex behavioral change, like teaching people how to change their
food choices, to stop smoking or how to log their macros, a more moderate approach is
warranted. There is an optimum level of behavioral changes you can ask from a person. If you
ask too little, you patronize them and induce the Pygmalion Effect. If you ask too much, you
overwhelm them and they won’t be able to cope. The optimum level of behavioral changes
depends on someone’s motivation level. The more motivated they are, the more things they
can change at once.
Most people thus do not fare best when overloaded with new information and tasks at the start
of the coaching. A common mistake PTs make is giving new clients 10 comprehensive do-ityourself guides. This may work for highly self-reliant individuals, but most people need to be
dripfed the information a bit more to avoid paralysis by analysis. After all, otherwise you could
just send them a link to PubMed and say ‘go to town!’
On the other hand, even for people with very little motivation, it’s still not the case that ‘one
step at a time’ works best. Even then a moderate amount of lifestyle change works best. For
example, it’s better to change someone’s dietary and exercise habits at the same time than to
try to focus on just one aspect of the fitness lifestyle at a time.
If a client’s motivation determines the optimal level of behavioral change, this begs the question:
how do you assess how motivated someone is?
How to assess someone’s motivation level
Part of this simply comes down to honing your people skills. However, here are some tips to
determine and predict client compliance based on my experience and the scientific literature.
Motivation vs. enthusiasm
Counterintuitively, by far the best predictor of poor motivation in Menno’s experience is that
the client tells you how motivated he or she is.
It’s normal for clients to be happy to start working with you, but truly motivated clients aren’t
that vocal about their motivation. It’s normal for them. Compliance is a given, not something
that needs to be shouted over the rooftops. Clients that tell you how ecstatic they are to start
their physique transformation, how they won’t go on holiday during the coaching period and
that constantly tell you they will do whatever you say are usually the people that will have poor
compliance. That’s not real motivation. It’s enthusiasm. And enthusiasm is short lived.
Missing data
The next factor to look at to estimate a client’s motivation and adherence is more obvious.
Clients that miss updates, workouts and weigh-ins have poor compliance.
In Menno’s experience, the best predictor of compliance is weight logging. Clients with good
compliance tend to immediately start logging their weight and they’re consistent about it. If
your client doesn’t start logging weigh-ins within a few days of the start of the coaching or they
routinely miss days, that’s usually a good predictor of future compliance problems.
Of all the available client data, why is weigh-in consistency such a good predictor of adherence?
Weighing yourself is a measure of someone’s ability to build habits. Clients that consistently
weigh themselves know how to create habits. Those that are inconsistent aren’t as organized.
Weight variance
Other than how often someone successfully logs their weight, high variance in someone’s
weight data is also a predictor of poor weight loss success. Usually if someone’s weight doesn’t
progress at all as expected based on their caloric intake and guidelines you learned in this
course, it’s due to compliance issues.
Large weight variability can also signal circadian rhythm disruptions that change water retention
levels, like poor sleep and high stress, or it can signal an overall highly variable diet, which as
you’ve learned above generally isn’t a good sign: successful people know how to harness the
power of routine.
Work capacity
If the reps in any set after the first increase, e.g. 80 pounds x 7, 9, 6, 10 reps, this generally
signals that the client isn’t training hard or isn’t warming up properly. You don’t get stronger
during a typical training session: you get fatigued.
In a minority of people with great work capacity, they might be able to do the occasional extra
rep in a subsequent set due to resting longer, but physiologically, that’s about it. Rather, lack of
training intensiveness is commonly the reason why someone’s reps across sets increase instead
of decrease.
The devil is in the details
Being vague and general is an indicator of poor compliance. Clients with good compliance will
send you an exact meal plan or their food log from e.g. MyFitnessPal.com when you ask what
they’re eating. Clients with poor compliance will often tell you it’s ‘usually like this on most
days’. That’s an indication they’re not tracking their macros accurately and they’re likely
Goal orientation
This is discussed in its own section below.
Delays in starting the program or any new program aspect is another good predictor of poor
compliance. People that are motivated to do something, they do it. And they do it now. Poorly
motivated people will defer what needs to be done or schedule it for later. Good examples are
clients that send you an email saying they’ll send you their caliper measurements tomorrow. It
takes about as long to take your caliper measurements as it takes to send an email, so time is
generally not the rational consideration here.
Finally, other than relying on predictors and indicators of a client’s motivation level and
program adherence, you can simply ask them. The key here it to ask objective and specific
questions. Menno has created such an assessment that you can send to your own clients.
Pt toolkit
Program adherence assessment sheet
When you look over the assessment sheet, you may think ‘duh’. Indeed, it’s all very obvious if
you think about it. But you’ll find that sometimes people admit to a blatant lack of adhering with
the diet in the assessment even though they never mentioned it to you during the coaching.
Again the key here lies in the specificity and concreteness of the questions.
To what extent can you motivate a client?
If you have a client with little motivation to exercise, you need to motivate them. There is no
doubt this is possible. We’ve already seen a big motivational factor is success: people are much
more inclined to work for something if they know it will pay off. Other motivational factors
include social pressure, intrinsic drive, an upcoming holiday, etc. But some individuals are just
inherently more motivated than others: they are genetically predisposed to be more motivated.
To what extent is our motivation to exercise genetically influenced?
To answer this question, we can look at heritability estimates. We can look at individuals we
know have similar genes, particularly identical twins, fraternal twins and children. Then we can
correlate this with how similar their exercise behavior is. This allows us to statistically estimate
how much of the variance in exercise motivation is due to genetics. This can be a bit abstract,
but if you are a visual learner, you can visualize an “exercise motivation pie chart” with multiple
slices. One piece of this pie is genetics.
A huge study of over 85 thousand twins of several northern European countries found that the
heritability estimate for exercise participation ranged from 48 – 71%. Genetics were more
influential than a shared environment, which was actually not a significant factor in this study at
The environment seems to be much more important for adolescents: “Between the ages of 13
and 16 years, environmental factors shared by children from the same family largely account for
individual differences in sports participation (78-84%), whereas genes are of no importance. At
the age of 17-18 years, genetic influences start to appear (36%), and the role of common
environment decreases (47%). After the age of 18 years, genes largely explain individual
differences in sports participation (85%), and common environmental factors no longer
A similar large study with 1432 Dutch siblings came to the conclusion that the heritability of
exercise participation was 69% for men and 46% for women, suggesting that women are more
influenced by environmental factors than men.
For high intensity exercise specifically, genetics seem to be even more influential. Higher
intensity of exercise shows a higher estimation of heritability in Finnish twins. Even if people are
motivated to exercise, they may not have the right genes for high intensity exercise, so it makes
sense that strength training suits only a more particular kind of person. Research has found
strong links between the ‘wanting’ neurotransmitter dopamine activity and other parts of the
brain’s reward circuitry and willingness to exercise. Personality type seems to influence what
kind of exercise someone likes.
In short, the motivation to engage in strength training appears to have a significant genetic
component. However, it is not nearly 100%. If we take 60% as the average contribution of
genetics, this means on a motivation scale of 1 to 10, you can in theory make a 4 point
difference in motivation. This would mean there’s the rare individual scoring a genetic 1 that
will never score better than a 5, but everyone else can at least score a 6. And a non-motivated
4 could become an 8: think of the formerly obese and sedentary individual that turned his or
her life around and is now the ‘fit freak’. As a coach, it is your job to make the most out of your
clients. The advice in this course should help you achieve that.
If you’re interested in more information about the genetic basis of exercise motivation, here’s a
bonus article.
Recommended reading
The genetic basis of exercise motivation
Is willpower limited?
So willpower, self-restraint, executive control, mental fatigue, task fatigue, decision fatigue and
boredom all generally come down to the same psychological phenomenon: the brain shifting
your attention to something else because it is no longer receiving sufficient instant gratification.
There is no limited resource, like a fuel, that is gradually used up. Realizing that willpower is not
a limited resource but rather essentially no more than task boredom obviously has major
implications for how to prevent ‘willpower failure’.
Exercising when fatigued
Common wisdom holds that it may not be a good idea to exercise after work when you feel
fatigued or already ‘willpower depleted’ as this will only further deplete your willpower and
leave you even more prone to overeating than you already were after a long day at work. (If
you think exercising in a mentally fatigued state will compromise performance, revisit the topic
on periodization.)
Based on the modern findings on willpower, such a mentally fatigued state is the perfect
moment to exercise. Since willpower isn’t limited and the real issue is in essence boredom,
immersing yourself in a different kind of activity is exactly what you need to rid yourself of the
mental fatigue. Exercise in particular is very effective at normalizing your mental state, similar to
meditation or a computer’s ‘reset’ button. As such, exercising in a mentally fatigued state
prevents rather than aggravates overeating.
A trick to get rid of mental fatigue
Exercise can effectively rid you of mental fatigue, but of course you can’t always go hit the gym
whenever you’re bored or tired. Fortunately, for other situations we can replicate some of the
arousing effects of exercise with something else that’s surprisingly effective: cold showers.
Yes, a cold shower is probably the last thing you want to take when you’re not feeling well. But
if you can muster the strength – or better yet, build a habit – to take a cold shower whenever
you’re feeling mentally drained, the benefits are immediate. “Exposure to cold is known to
activate the sympathetic nervous system and increase the blood level of beta-endorphin and
noradrenaline and to increase synaptic release of noradrenaline in the brain as well.” Pilot
research has demonstrated anti-depressive effects of cold showers and hydrotherapy in general
is an ancient and now evidence-based therapy for a wide range of problems, but the effects are
really so obvious that you shouldn’t need research to tell you what happens when you take a
cold shower: no matter how drained you felt beforehand, afterwards you feel energetic.
Note: There’s a lot of speculation about near magical benefits of cold showers circulating the
internet. You’re advised to take most of that with a grain of salt, but just as with meditation,
there’s truth underneath.
Dealing with overeating during a diet
The most common situation where ‘willpower’ fails is when trying to white-knuckle a diet.
Most people think dieting is supposed to suck and the way forward is iron discipline and
willpower. This couldn’t be more ineffective, evidently. Most people just end up being a time
bomb ticking towards the next binge.
People have only a limited ability to change their core personality traits: you are better off
learning to cope with your personality by i.a. forming implementation intentions. (If you don’t
remember what those are, revisit the course topic on lifestyle factors.) The same holds for selfrestraint: don’t focus on trying to improve your self-restraint, because it’s not limited in the
first place. Rather, learn to deal with your psychology and prevent your attention from shifting
to food.
The key to success lies in specificity and concreteness. That’s why implementation intentions
are so effective: they are practical. And that’s why most motivational talks are so ineffective:
they’re vague and don’t specify which behaviors exactly should be changed.
Here’s a more practical framework to help prevent overeating during a diet.
1. Identify the situations in which overeating occurred.
Simply asking your clients to do this often solves the problem already, as the solution
becomes readily apparent.
2. Determine the drive to overeat.
The following categories are useful.
a. Hunger.
b. Self-medication. This includes boredom, stress related eating and most kinds of
‘decision fatigue’.
c. Mindless eating.
3. Provide concrete, specific advice on how to deal with this problem in the
future, preferably implementation intentions.
The solution should aim to achieve the following.
a. Hunger: make the diet more satiating and implement appetite control (discussed
in the topic on ad libitum dieting).
b. Self-medication: increase wellbeing and incorporate task breaks to prevent
attention from shifting to food.
c. Mindless eating: planning, e.g. not eating in front of the TV.
When helping a client prevent overeating, your skills as a psychologist will be put to the test.
The above guidelines provide a great starting point, but you will need to develop experience.
One of the most valuable kinds of experience is having been in your client’s shoes, i.e. having
been as lean as they’ve been. That’s why it’s beneficial for every coach to have competed in a
physique show once even if they have no competitive aspirations.
In addition to the above framework and tips, when a client is having trouble adhering to the
diet, you again want to focus on empowerment. To internalize their locus of control, feel free
to send your paying clients the link to the course video on willpower.
Case study: dealing with overeating
As an example of how to implement the above framework, here’s the exact exchange between
Menno and one of his clients. Menno asked the client to identify exactly during which situations
the client was overeating and list them.
Client: 1. I’ve gone over my allowed calories a couple times after very long days and stopped to get
something quick rather than prepare a meal at home.
Menno: The solution here is planning. It's good to prepare your food in bulk so that many meals
are already available and just have to be reheated/finished/grabbed from the fridge. This also
saves a ton of time compared to preparring each meal on the spot. I also like to have some
extremely convenient back-up meals available at all times. I personally, for example, in my
current situation always have a few cans of either mussels, low fat cheese or smoked turkey
and gherkins available that I can eat with minimal prep (tip: sucralose sweetener in traditional
mustard sauce makes low calorie honey mustard sauce).
Client: 2. I’ve had times eating too much out of boredom on weekends.
Menno: This one's trickier, as the solution is to increase your wellbeing in other ways.
Boredom eating is essentially self-medication. I find it helps to have zero/low calorie snacks
available. Coffee's a common one that's nice, as it's hot, which helps with satiety as well, but
you can also make great low kcal fruit flavored gelatins and an awesome granita with diet 7-Up,
a bit of lemon juice and fresh mint leaves that you freeze.
A trick rule to get your clients in the gym
Certain clients have such poor compliance that they’re not even consistent in going to the gym.
When you’re dealing with such a client, here’s a simple trick to increase their compliance. You
agree with them that they can skip training sessions if they feel like it, but they can only make
that decision 60 minutes after having taken their pre-workout (usually caffeine).
At first glance, you may intuitively recognize why this works, but it may also seem too simply to
work very well. Here’s why it works. Again contrary to our intuitions, humans are remarkably
bad at predicting how we will feel in the future. We suffer from a wide range of affective
forecasting biases, as this is called in psychology. You may think you can predict how you’ll feel
in certain future situations. You can’t. Psychological research has found this time and time again
for even major life events. As a telling example, pretty much everyone agrees that winning the
lottery will improve their life’s happiness at the very least a little bit and everyone agrees that
losing a limb will make them miserable. Surprisingly, neither is true. Both only impact happiness
in the short term. Over the year(s), happiness returns back to baseline levels in research. The
bias that we suffer from here is that we neglect our mental adaptation, the change in our frame
of reference after these events that ultimately makes richness or disability feel normal again.
For our particular example of going to the gym, the bias we are dealing with is projection bias.
Projection bias is the tendency to extrapolate our current feelings to the future. We think that
how we feel now is how we feel then, even when there is an obvious explanation for how we
currently feel. A striking example of projection bias is Dan Ariely’s porn experiment. In a study
design that would probably no longer pass any ethics committee on earth, the researchers
asked a group of men to fill in extensive questionnaires about sex twice. Once when not doing
anything. Once when jerking off to pornography. When aroused, on a scale of 1 to 100, the
answer to ‘Can you imagine being attracted to a 12-year old girl?’ went from 23 to almost 50%.
‘Would you slip a woman a drug to increase the chance she would have sex with you?’ went
from 5 to 26. ‘Would you keep trying to have sex after your date says “no”?’ went from 20 to
almost 50%.
This doesn’t just show that men are pigs. It shows that humans are fundamentally incapable of
ignoring their current feelings when thinking of their future feelings, even if the reason for their
current feelings is literally staring them in the face.
We feel tired now, so we don’t go to the gym because we think we’ll still feel tired. If you’ve
gone to the gym anyway in these situations, you’ll know that the fatigue was entirely
psychological and there is nothing wrong with your neuromuscular system. And after warming
up, the mental fatigue almost always disappears completely. Since it’s very hard to get someone
to go the gym when they think they won’t enjoy it, it’s much easier to change their current
feelings. By having them consume their pre-workout, they become energized and as a result,
they often go to the gym anyway.
Try it. This simple self-trickery works wonders in certain clients.
Cheat meals
Many clients will ask you if cheat meals, or, euphemistically, if refeeds are included in the
program. You’ve learned in the course topic on human metabolism why refeeds are not
included, so let’s focus on cheat meals.
A cheat meal for our purposes is a meal that does not fit the planned macros, normally
containing many more calories and foods that are not conducive to health or muscle anabolism
(more on that in the food choices course topic).
From a Bayesian perspective, a certain food is either worth it or it’s not. Either its benefits
outweigh the costs or they don’t. You analyze its macros, health benefits, satiety index, etc. and
thereby determine its value (utility, as economists call it). If the value is high compared to other
foods, you fit it into your macros. If not, you don’t.
To give a practical example, a cheat food Menno used to eat was dürüm döner, a wrap with
meat and garlic sauce. Obviously not a great health food due to the processed meat, sauce and
wheat, but it has some nutritional value, including enough protein for a meal. “I stopped eating
it because a new consumer report showed that most döner contains significant amounts of
trans fat. That tipped the scales for me, so I’ve never eaten döner since.”
But is this kind of rationality feasible for all your clients? Can’t a cheat meal provide
psychological relief?
Yes, a cheat meal can provide psychological relief. Very short term relief that comes with
significant costs that many flexible dieting proponents don’t realize because they have never
studied psychology.
First, using food as a reward teaches you to consume that food when experiencing emotional
stress. A cheat meal basically creates your own comfort food. Guess what happens when the
dieting gets hard? You turn to the comfort food. This is fundamentally toxic to lifestyle change
and it is probably why people self-report that processed foods are more addictive than whole
Secondly, cheat meals glorify the cheat foods. If you understood range-frequency theory
correctly, you should see that creating a high point in your reference set makes all other points
in your reference set seem like they are less.
Concretely, a very tasty cheat meal makes all your regular meals less tasty. The research on this
is still in its infancy, but your liking for salty and sweet foods is influenced by how much you eat
of them [2], though one study found that only the intensity but not the pleasantness of sugar
was affected by how much sugar people consumed. Moreover, your preference for sweet foods
can grow over time with increased sugar consumption and your preference is not always
correlated with your ability to taste sweetness, indicating that food preference is not merely a
genetic trait.
In short, you like the type of food you regularly eat. So by not having cheat meals, not only
does your average diet enjoyment increase, you also don’t miss the cheat food as much when
you don’t eat it.
Taste entrainment is a reason why people tend to naturally gravitate towards high fat or high
carb diets with few people naturally selecting balanced diets. If you’re used to a high fat diet,
you don’t miss starches and vice versa. So for compliance it can be beneficial to exclude certain
food groups. You learn to like what you can eat and you don’t miss what you don’t eat.
Thirdly, by eating a cheat food you make the food more salient in your memory and induce a
craving for it [2]. Many people intuitively think giving in to a craving makes it disappear, but if
there’s one thing you learn in behavioral science, it’s that people are horrendously bad intuitive
The best way to kill a craving is to starve it [2]. Many people with a weekly cheat meal or day
find themselves thinking about it the whole week. If Saturday is ‘pancake day’, Sunday to Friday
are “’thinking about pancake day’ day”.
Whereas if you never eat a food, you simply forget about it and you never miss it anymore. It
disappears from your mind’s internal menu, just like words disappear from your active
vocabulary when you stop using them. Most processed foods simply stop looking like something
edible altogether.
Based on the above disadvantages of cheat meals, it’s no surprise that people with cheat meals
or days are less successful than those who focus on consistent lifestyle change.
The common practice in bro bodybuilding circles of being strict during the midweek and do
whatever you want in the weekends is similarly destined to fail. Yes, there are a few (mostly
drug using) bodybuilders that can make it work, but for every ripped guy you see eating ice
cream on Youtube, there are a thousand fat people wondering why they’ve never been able to
maintain their sixpack.
So while it’s all fine and dandy that you can fit some candy into your macros without it
impairing your gains and there is no such thing as ‘unhealthy food’, from a psychological
perspective it can actually be helpful to think in terms of good and bad. That’s probably why the
idea of ‘eating clean’ still survives in bodybuilding: it benefits compliance.
Lifestyle change is a reality. It’s a cliché because it’s true. People that successfully maintain a
sixpack or cellulite free body have by and large changed their lifestyle around. IIFYM is a great
idea for robots, but the vast majority of people fail on it. Adopt a healthy fitness lifestyle, stay
fat or spend your life in diet limbo where you never really attain or more importantly maintain
the physique you want. Those are the options for most people. Pick one.
Dealing with specific food cravings
Food cravings are another topic that is taken for granted by most non-psychologists. A ton of
myths surround the topic of why you crave specific foods, but few people doubt the existence
of cravings for specific foods.
The truth is, however, that food cravings in the sense of addiction are a myth. You can become
addicted to eating in general but not to certain foods. Classical addition syndrome is a
pharmacological effect whereby the brain’s dopaminergic system is sensitized and the
serotonergic system is desensitized. This creates increased ‘wanting’ and decreased ‘liking’ for a
certain substance, causing you to go to ever greater lengths to consume more and more of the
substance. Food doesn’t have this effect.
Rather, people self-medicate on comfort foods and they eat when they’re hungry. That’s why
everyone ‘craves’ the same foods. It’s always highly palatable and energy dense food that is rich
in carbs or fat, often both, and usually they’re sweet or salty; rarely sour, bitter or umami. You
simply like certain foods better than others and you want to eat what you like. No mystery, no
magical fix.
And yes, that includes chocolate. Chocolate addiction is a myth (at least for psychologically
healthy individuals). Women typically like chocolate more than men, but neither gender actually
suffers from chocolate induced cravings. By now there is of course cultural entrainment of
chocolate cravings, another nocebo effect. So many women hear about chocolate cravings
when dieting that they may get them simply because they’re expected to.
So what do you do when a client reports cravings for certain foods? You tell them what you
just learned. There is no physiological need for that food, nothing in your body that makes you
want to eat that food. You just want to eat that food because it’s tasty. And again, the best way
to kill a craving is to starve it, not to indulge in it.
Note: We’ll come back to using food as self-medication in the course topic on stress.
Flexible dieting vs. meal planning
It’s cool these days to be a proponent of ‘flexible dieting’, even though no one that uses it has
an operational definition of the term. It aligns well with the common wisdom that ‘variety is
key’ in your diet. Eat whatever you want and every day you can eat new things, depending on
what you feel like that day. It’s flexible. And everyone knows flexible is a good word.
Yet flexible in this case often ends up being a euphemism for disorganized. The practice of
making each day different based on how you feel stands in stark contrast to the vast majority of
successful bodybuilders. By and large, successful bodybuilders have almost no variety in their
diet. They have mastered the power of habit and they eat a fixed meal plan across each week.
More importantly, in scientific research, people are generally more successful on pre-set meal
plans than when they have to fill in their macros themselves.
The reason for meal planning’s major success over variety is that meal planning takes the
decision making away from dieting. Remember that diets fail when you combine hunger with
decision fatigue. Making your daily food choices based on your current appetite is thus the
absolute worst way to set up your diet from a psychological perspective. It ranks right up there
with doing your shopping when you’re hungry. That’s the worst way to make sure you buy
foods that are conducive to your physique development. (If you don’t understand why, go back
to the section on affective forecasting failure and projection bias: hunger creates severe
projection bias.)
Recommended reading
Diet programs and compliance: do prepared meal programs increase adherence?
Why you shouldn’t set goals
Another highly misunderstood topic in fitness is goal setting. It is widely believed that goals help
you stay focused and increase motivation, so many clients will tell you they want to look like a
certain fitness model, they want to have bodyweight X and body fat percentage Y with a bench
press of Z.
Setting goals like this is disastrous for compliance. Why? These kind of goals are known as
performance goals. You focus on the achievement, on the outcome or the resulting ability you’ll
Performance goals vs. a growth mindset
Performance goals stand in stark contrast to a growth mindset, where the focus lies on the
process and self-improvement rather than the endpoint.
A wide range of studies in academics, sports and the corporate world consistently show that
people with a growth mindset outperform people with performance goals. (See e.g. Carol
Dweck’s book Mindset, her seminal publication on goal orientation or Nicholls’s Coping in Sport:
Theory, Methods, and Related Constructs.
Specifically relevant to gym goers is that performance goals and other forms of extrinsic
motivation to exercise do not predict how often men are actually willing to go to the gym,
whereas intrinsic goals do significantly predict gym attendance.
A popular version of the growth mindset in sports is coach John Wooden’s success rule to ‘to
do your best to become the best you are capable of becoming’.)
When you think about it, it’s actually very obvious. Performance goals are ego motivated. It is
no more than the expression of a desire to have sixpack abs or to squat triple bodyweight.
These goals are empty. Everyone wants these things, some people just more than others.
People with such a goal will be willing to do something for it, but as soon as things get hard and
they start failing – and everyone fails in fitness – they lose motivation. They’re focused on the
endpoint and failure makes you lose sight of that.
Being motivated only by how well you’re fulfilling your performance goals is particularly
problematic when it comes to fat loss, because people tend to have extremely unrealistic
expectations of how much fat they can lose in a short time.
You would expect people with any type of motivation to still see some correlation between
motivation and success or at least persistence, but some research even finds the opposite for
performance goals in weight loss: the higher someone’s weight loss goals, the less likely they are
to stick with the diet.
On the other hand, people with a growth mindset don’t just want to be a 500 pound squatter:
they want to become one. This difference in orientation makes a major difference to your
coping behavior. When you have a growth mindset, failure is a learning point, not a roadblock.
Your mindset also influences your success by affecting how your diet adherence changes after
your training sessions. People that perceive their workouts as ‘chores’ they need to perform in
order to get to their goals are more likely to ‘reward’ themselves with snacks afterwards and
tend to eat more than people that perceived the activity as fun. Now, heavy strength training
isn’t really ‘fun’ in the traditional sense. ‘Fulfilling’, perhaps. However, with a growth mindset
you don’t need to view your training sessions as anything: it’s a routine in your lifestyle.
Menno analyzed the effect of goal orientation in his clients and the results were astounding. “I
went back over all my client files and classified clients based on whether they asked me to set
specific goals for strength or body composition (performance goals) or whether they simply
asked for fat loss, muscle growth or strength development (growth mindset).
There was an absolutely major difference between the 2 groups. I didn’t even have to run a
statistical analysis on the data. I don’t have many drop-outs in my clients, but practically all of
them were performance goal setters. And virtually all of my greatest success stories were in
clients with a growth mindset.”
So what do you do when a client asks you to set goals for them? You tell them what you just
learned. Focusing on the endpoint makes you less motivated to do the things you have to do to
actually get there. Adopt a growth mindset and focus on the now instead of the future: concern
yourself with your daily meal plan and your next workout and success will come.
Do not focus on the endpoint: focus on what you have to do to get there.
Diet breaks
Diet breaks are a popular recommendation by non-psychologists based on the intuitive appeal
to ‘some downtime’ or ‘relief from the dieting’. As you should be able to predict by now,
psychological science has something different to say about diet breaks.
Wing & Jeffery (2003) studied the effect of diet breaks on compliance with weight loss dieting.
They divided people into 3 groups.
The control group went on a weight loss diet without breaks.
The short break group went on the same diet with 3 2-week diet breaks in between.
The long break group went on the same diet with a single 6 week break midway
through the diet.
In contrast to popular wisdom, the researchers hypothesized that the diet breaks would be
disruptive to diet compliance, because when people fall off the diet wagon, they often don’t get
back on. However, that’s not what happened. Most people did not have major problems with
getting back on the diet after the break, regardless of the break’s length. This has led much of
the flexible dieting crowd to herald this study as the vindication of diet breaks.
However, if you logically think about the study results, using them to support flexible dieting or
diet breaks doesn’t make any sense. Diet compliance was similar in all diet weeks in all 3
groups. So no, the diet breaks did not cause people to fall off the wagon completely. But they
didn’t help either. So the diet breaks were simply a waste of time.
Moreover, a closer inspection of the results reveals detrimental effects of the diet breaks.
“...lasting differences occurred after the third break of the short break group when participants
reported less frequent self-monitoring, less frequent self-weighing, and a trend toward greater
consumption of restricted foods.
The long break group also had a trend toward greater consumption of restricted foods for the
week after the break.”
The greater difficulty with food restrictions after the diet breaks is exactly what you’d expect
from the psychology of cheat meals and food choices. After a diet break your mind’s internal
menu is filled with foods that are not conducive to your fat loss goals. As a result, you have
more difficulty not eating these foods any more.
The greater difficulty with self-monitoring after a diet break is also not surprising. Weighing
yourself and other forms of progress tracking are very much a matter of routine and habit.
Breaks cause you to break your habits.
The researchers somewhat dismissed these concerns because in the long run, weight loss was
similar between the 3 groups. However, take a look at the actual data plotted below. The nobreak group achieved a level of weight loss in 7 weeks that groups with the diet breaks took 16
weeks to achieve. If these were strength trainees, the no-diet group could have spent 9 weeks
In short, diet breaks introduce foods in your internal menu that are too caloric to fit into your
cutting diet without suffering hunger. Moreover, diet breaks cause you to fall out of your
routines and break your habits. In the best case scenario, diet breaks are ‘merely’ a waste of
time. At worst, they are fundamentally toxic to lifestyle change, because diet breaks by
definition imply that the diet is temporary. The word ‘diet’ actually comes from Latin via Greek.
Diaita meant ‘way of life’, not ‘unsustainable period of self-deprivation resulting in short term fat
loss’. It’s best to stick with the original definition in terms of application.
If you feel like you need a diet break, you should probably take a long, hard look at your
lifestyle. If your lifestyle is not something you can sustain for weeks or months, how are you
going to sustain it for the rest of your life? You need to address the problems, not run away
from them and come back to see if they’re still there.
Managing social eating events
Having a good physique does not mean you have to shy away from every wedding, Christmas
dinner or birthday party. Here’s how to maintain your physique while eating out.
Pt toolkit
How to manage social eating events
Feel free to send this guide to your paying clients.