The Cardio Conundrum

I was going to start this blog with 'this is kind of a rehash on this topic...' but then I went to a fitness convention this past weekend...the same weekend as the NYC marathon. I soon realized that rehash is sometimes necessary. So my new opener is this: 'you probably have no idea how much this topic (cardio) needs to be addressed...again.' So I have compiled a bunch of relevant points, links and quotes from real-world experts on the topic of cardio & aerobics: what's wrong with it, why there are better choices and how you may be damaging your health.

cardio, aerobics, marathon, Poliquin, Paul Chek, Mike Boyle, Alwyn Cosgrove

Keep in mind a few things on why I have this stance on cardio. I work in NYC and my clients are all really busy. They have limited time to invest in exercise; every minute is valuable, so they want to make the most of their time.

Also, I work with some clients who have damaged their metabolism or are chronically stressed (from undereating, not sleeping enough) and in many cases, conventional exercise is a stress their body can not tolerate (despite their sincere, yet misplaced desire to ‘burn off’ their stress).

Finally, there is a disproportionate amount of bad information in the media and trendy group fitness classes touting cardio and aerobics; therefore, I am offering a strong, yet rational response to this conundrum.

So, I am not totally against cardio for all people; rather I am against it for a good majority of people most of the time.

Also, the coaches, experts, authors (or whatever you want to call them) I’ve quoted here, similar to me, have a variety of training protocols that deliver different results for clients with different needs. So don’t take the quotes out of context.

And NO, this does not mean I endorse all of them. Some of them I completely disagree with on other points. I am sharing relevant information from various people who, in my opinion, are correct in their presentation of this particular topic. These people may have radically different opinions in other areas and I am not comparing these people or endorsing all of their work in this blog post. Stay focused on the topic and don’t get caught up in other differences. Cool?

First Things First…

Fitness, Strength & Conditioning professionals differentiate between the overused and erroneously used terms (cardio, aerobics, warm up, endurance training) and we also understand that different types of results are derived from different training protocols. But the vast majority of people don’t seem to get this.

Most people who do ‘cardio’, ‘aerobics’ or run marathons, have one or two ideas in mind when using these terms (that it is ‘healthy’ or helps ‘burn fat’)… and many people unfortunately prefer sound bites & thought killing cliches instead of learning about the topic. So for those interested, I say thank you! Here is a link explaining the different energy systems used in human movement, performance & metabolism:

Energy Systems Defined: LINK

For the purpose of this article, I am going to talk about ‘cardio’ the way most people understand & use it.

Six Reasons Why Aerobic Work is Counterproductive by Keith Alpert, Strength Coach from Boston

1. Continuous aerobic work plateaus after 8 weeks of training so anything more is counterproductive.

2. Aerobic training worsens power locally and systemically – in other words, it can make you slower.

3. Aerobic training increases oxidative stress which can accelerate aging.

4. Aerobic training increases adrenal stress which can make you fatter and produce other undesirable health consequences

5. Aerobic training increases body fat in stressed individuals by contributing additional stress.

6. Aerobic training worsens testosterone/cortisol ratio which impedes your ability to add fat burning lean muscle.


Charles Poliquin

Cardio Poliquin The Cardio Conundrum  ‘Jogging and tons of cardio are great for weight loss, so are cancer and AIDS. Unfortunately, too much of the weight loss comes from the destruction of muscle tissue. For many people, running marathons or doing triathlons is a passion. So if you’re going to do these activities, do everything you can to preserve your muscles…’

‘Cardiovascular training ceases to work after 6 weeks of training. Period. It has been documented in the scientific research in exercise physiology as early as 1973, and yet the information has not reached mainstream fitness. If it worked for longer than that, you would have made progress wouldn’t you? Insanity has been defined as doing the same things over and over again, and expecting different results.’


The (Many) Negatives of Aerobic Training

Bad News #1 – Aerobic Training Raises Cortisol and Accelerates Aging

Bad News #2 – More Inflammation and Oxidative Stress from Chronic Aerobic Exercise

Bad News #3  – Decreased Reproductive Size and Function, and Lower Androgens in Animals

Bad News #4 –  Acute Oxidative Stress and Cortisol Elevation from Aerobic Exercise

Bad News #5 Long-Term Aerobic Exercise Compromises Immune System

Plus The Good News: Top Three Thing You Can Do Instead of Aerobic Exercise (click on link)


Paul Chek

Paul Chek, author & founder of The Chek Institute. He is a pioneer in corrective exercise, wellness and performance. Paul Chek has influenced the fitness industry in more ways than you’re probably aware of.

Cardio Chek1 The Cardio Conundrum

‘Too many fitness professionals are invested in the No Pain No Gain ideology. However, when we work OUT, as the term implies, we spend our life force (or vitality). All of the systems in our body rely on energy to function. So if you have an already stressed system and then you add the stress of working OUT on top of it, you force your body into an even deeper catabolic or stressed state. The stressed body holds on to everything. It holds on to water. It holds on to fat. Then you have people wondering why they go to their stressful job all day, fight with their husbands, worry over their finances, eat non-organic processed foods and then come to the gym and run on a treadmill for an hour and still can’t lose that weight. We need to stop only working OUT and start to do some working IN. To heal yourself out of this stressed state, try yoga, meditation, a walk outside or tai chi. Health is a matter of balance. Learn to take care of yourself and to take care of the earth. You can’t make chicken salad from chicken shit.’

For more of Paul Chek’s perspective on what’s wrong with cardio, including an evolutionary understanding & the influence that cardio equipment manufacturing has on consumers, read this: LINK


Mike Boyle

cardio Boyle The Cardio Conundrum  Mike Boyle is a Strength & Conditioning Coach for many world class collegiate & professional athletes. He is an international lecturer, author of two books and multiple DVD’s on Strength & Conditioning, Weight Loss, and Reconditioning.

‘What’s aerobic training good for? Nothing… I think the concept of aerobic base work is a complete falsehood. I don’t believe there is any need for aerobic base, I think there is just a need to get in better shape to build work capacity. Aerobic training is for somebody to get fit enough to do anaerobic training.

Does this mean we have been lied to? Yes, absolutely, positively we have been lied to’


Alwyn Cosgrove

Cardio epoc The Cardio Conundrum  A sought after ‘expert’ for several of the country’s leading publications including a regular contributor to Men’s Health magazine, Alwyn has co-authored three books in the “New Rules of Lifting” series and currently spends his time consulting on fitness training, training clients, training his staff at Results Fitness, speaking on the fitness lecture circuit and coaching fitness trainers worldwide in their businesses.

In his article ‘Hierarchy of Fat Loss’, Cosgrove explains the most effective to least effective methods of exercise for fat loss. Nutrition sits on top of the hierarchy before exercise which you should all be aware of by now. So if you want to understand the importance of different types of exercise for fat loss, this is an excellent article.

“Quite simply aerobic training is grossly over-rated. Over rated for health, over rated for performance and definitely over rated for fat loss. My personal opinion is that it is practically useless for fat loss, but the real problem is aerobic training’s detrimental effect on strength and hypertrophy work”

When I said “Aerobics are useless for fat loss” what I meant was “aerobics are useless for fat loss”. Is that clearer?

LINKHierarchy of Fat Loss

LINK – Secrets of Fat Loss Training

Mel Siff

Cardio Siff The Cardio Conundrum  Mel Siff, PhD, MSc, author of ‘Supertraining’ and ‘Facts and Fallacies of Fitness’. Siff, a sports scientist and biomechanist, specialized in human performance, fitness, sporting excellence and injury rehabilitation.

‘All too often, fitness is regarded as being synonymous with cardiovascular endurance, which is but one of several factors determining overall fitness. Actually, fitness for one’s daily activities places far greater demands on postural and anaerobic qualities than cardiovascular endurance.

‘Cardiovascular endurance actually is not required in the vast majority of Olympic sports and therefore, is not as significant in sporting preparation as is suggested by numerous exercise scientists. It certainly can play a role in improving the the cardiovascular system, promoting capilliarisation and facilitating recuperation, but cardiovascular or aerobic’ training cannot enhance the other components of sport specific fitness, such as strength, speed, power, flexibility and muscle endurance.

Cardiovascular training performed as a preface or warmup to strength conditioning or other forms of training in any given workout can be especially counterproductive, since it tends to inhibit the production of strength, power, speed animator skill. If done at all as part of a training complex, it is highly advisable that it is done after all other forms of fitness training.’

from Facts & Fallacies of Fitness

Remember that the next time you see a client warming up before their personal training session…which is almost always.

Jen Grasso

Jenn is a Health and Physical Educator, Strength and Conditioning Specialist for Renegade Strength and Conditioning 

cardio JGrasso1 The Cardio Conundrum  ‘The biggest mistakes I see women making is that they are afraid to or don’t train heavy and they do too much traditional cardio. Girls need to understand that if they increase their muscle mass they will decrease their bodyfat and look and feel significantly better.

I find females either eat too much or not enough of the right kinds of food which will hinder their quest to look and perform better. The low protein, starvation type diets that many girls use to get in shape are very counterproductive and only lead to a flat, smooth look where you end up losing muscle but not much bodyfat.

Stick to a diet which consists of only real, whole, organic foods that you could pick, grow or kill.  Avoid all processed foods, fake foods, food additives, and agricultural chemicals at all cost.’



Jason Ferruggia

Jason is world renowned fitness and performance enhancement specialist. He is the head training adviser for Men’s Fitness magazine and regular contributor to Men’s Health, Maximum Fitness, Muscle & Fitness Hers, Shape, Today’s Man & MMA SportsMag. Owner of Renegade Gym… ‘where we have never had a treadmill, stationary bike or stairclimber, yet have always gotten people absolutely shredded time and time again.’
cardio JFeruggia The Cardio Conundrum

I haven’t changed my stance on traditional cardio at all. From the get go I have always said there are two options when it comes to cardio and they are both at extreme opposite ends of the spectrum. You can either do very high intensity cardio (sprint) or you can very low intensity cardio (walk). Two of the leanest groups of people on earth follow these methods. Sprinters obviously sprint and bodybuilders such as Dorian Yates and other behemoths walk.

It’s the midrange stuff that I’m opposed to and that presents a problem for most people. I have never changed my opinion on that. The way most people do cardio sucks, in my opinion.

When you hop on a machine and go at it with moderate intensity for 30-40 minutes you will get all of the negative effects associated with cardio (increased cortisol, muscle loss, overuse injuries, decreased power output- meaning you’ll be less explosive, etc.). When do the same thing at a high intensity you’re totally fucked. That’s why I have always maintained that you should do one extreme or the other. Or both at different times of the day and week.


Dax Moy

Author of ‘The Elimination Diet’, a performance enhancement specialist and master personal trainer with studios in and around London. Voted one of the UK’s leading fitness experts, Dax is a regular guest on TV, radio and print publications on the subject of health, fitness and the performance mindset.

cardio Dax CB The Cardio Conundrum

Dax (left) and Craig Ballantyne (right). Ballantyne is author of ‘The Dark Side of Cardio’, creator of Turbulence Training and pioneer in body weight training for fat loss. Apologies to the guy in the middle, email me and I’ll add your name.

‘A prime example of using the wrong tool can be seen if we look at the common approach to cardiovascular training (CVT). Most women incorporate CVT into their programmes primarily as a method of weight control and body fat reduction. Using all manner of methods from rowers to steppers, treadmills to bikes and cross-trainers to ‘aerobics’ classes, women in gyms up and down the country, and indeed the world, can be found spending a disproportionate amount of their total training time on exercises that… …wait for it… …may actually be making them fatter! That’s right, it’s not a typo. The much hailed panacea of aerobic training can actually contribute to making women (and men too) proportionately fatter than before they started training.

The longer we engage in higher level aerobic activities such as those typically included in a workout, the more we secrete a nasty little group of hormones called ‘glucocorticoids’, with the stress hormone ‘cortisol’ chief amongst them. One of the lesser known qualities of cortisol is that it is catabolic in nature, meaning that it breaks down muscle tissue along with fat in order to metabolise this stored energy for immediate fuel.



Rachel Cosgrove

Author of ‘The Female Body Breakthrough’, owner of Results Fitness, columnist for Women’s Health Magazine and spokesperson, consultant for Fortune 500 companies, contributor to the New York Times Best Seller, ‘The Big Book of Exercises’ and the ‘Women’s Health Book Look Better Naked.’
Cardio Cosgrove The Cardio Conundrum

‘After completing my Ironman, I made fat loss my primary goal for eight weeks. I eliminated all steady-state endurance exercise. No running, biking, swimming, or anything else in the steady-state….

What happened? Like magic, my abs came back! I dropped fifteen pounds of fat in an eight-week period and my body returned to being strong, defined, and lean. I no longer looked like a flabby endurance athlete, and I did it in a quarter of the time, compared to the aerobic training.’


In this article ‘Top 5 Ways to Gain Bodyfat’, Rachel shares her insight on aerobic exercise, undereating, low fat & low calorie dieting: LINK

Al Sears, MD

Cardio Alsears The Cardio Conundrum  Author of ‘PACE: Aerobics and Cardio are Dead’, a board-certified clinical nutrition specialist, one of the nation’s first board-certified anti-aging physicians, writer and researcher.

‘When hunters hunt, they walk for hours, and only when they are moving in on their prey or confronted by another predator do they run, sprint or fight. And these bursts of exertion are short-lived and followed by rest.

It’s true in the animal kingdom, too. When animals fight or run, it’s a short burst of energy. It’s never an extended, medium-intensity effort, like when you’re jogging. All of your body’s mechanics are tuned to this short burst of activity.

That’s why jogging, cardio and aerobic activity ultimately leave you fat, slow and injured. Because your body is not designed for long-duration activity, your heart and lungs lose their ability for maximum, peak performance.

This is the trade-off you make when your body has to adapt to this unnatural type of exercise. Your body stores fat and loses muscle as it tries to cope with running for long periods or other types of cardio or aerobics.

When you exercise within your aerobic limit, you don’t improve your aerobic capacity. That’s because it trains your heart, lungs and muscles to work at a certain level. But it does nothing to improve their conditioning or help you build real strength. And if you exercise at medium intensity, you’ll never hit your maximum exertion level – and that’s where you get the greatest benefit from your exercise.

What’s worse is that working out in your “aerobic zone” causes “shrinkage” – smaller muscles, smaller heart and smaller lungs. This wipes out the reserve capacity in both your heart and your lungs. Reserve capacity is vital to protect, energize and strengthen your heart and give it the extra “pumping power” it needs in times of stress.


Fat Burning Zone Debunked

Alan Aragon

Alan Aragon, Bachelor and Master of Science in Nutrition, is a continuing education provider for the Commission on Dietetic Registration, National Academy of Sports Medicine, American Council on Exercise, and National Strength & Conditioning Association. He is author of ‘Girth Control: The Science of Fat Loss & Muscle Gain’ and monthly research review ‘Alan Aragon’s Research Review’ (AARR), an unbiased monthly critical analysis and application of the latest research pertaining to nutrition, exercise, and supplementation.
Cardio Aragon The Cardio Conundrum
Summary of ‘Myths Under The Microscope Part 1: The Low Intensity Fat Burning Zone

In acute trials, fat oxidation during exercise tends to be higher in low-intensity treatments, but postexercise fat oxidation and/or energy expenditure tends to be higher in high-intensity treatments.

Fed subjects consistently experience a greater thermic effect postexercise in both intensity ranges.

In 24-hr trials, there is no difference in fat oxidation between the 2 types, pointing to a delayed rise in fat oxidation in the high-intensity groups which evens out the field.

In long-term studies, both linear high-intensity and HIIT training is superior to lower intensities on the whole for maintaining and/or increasing cardiovascular fitness & lean mass, and are at least as effective, and according to some research, far better at reducing bodyfat.


The Myth of The Fat Burning Zone

cardio zone The Cardio Conundrum

Travis Saunders is a PhD student, obesity researcher, and Certified Exercise Physiologist. Peter Janiszewski has a PhD in Exercise Physiology. He’s a published obesity researcher, lecturer, and an advocate of scientific knowledge translation.

The main error with the fat burning zone premise emanates from a basic misunderstanding of absolute (total) versus relative (proportional) values

It is absolutely true that in a relative sense, the lower the exercise intensity the greater the reliance on fat as a substrate for energy. As the exercise intensity increases, the relative proportion of fat oxidation decreases while that of carbohydrate increases. However, the value of interest to anyone attempting to maximize fat loss is not what percentage of energy comes from fat during the exercise (relative), but how much fat is oxidized (absolute). This is where the fat burning zone breaks down…

Another reason the fat burning zone is inaccurate is because during more intense exercise TOTAL CALORIC expenditure is much higher.

Lyle McDonald

Lyle McDonald is the author of several books including ‘The Rapid Fat Loss Handbook’ and ‘The Protein Book’. From his website, ‘Whether your goals are fat loss, muscle gain, or improved performance, if you are looking for scientific, fact based information, you have come to the right place. I’ve helped thousands to change their bodies for the better.’

What Defines Cardio in Terms of Too Much – Q&A

Question: This is a follow up question for your last QA. It is often said that too much cardio on a restrictive diet is “bad”. ?With NEAT in mind, I wonder exactly what defines cardio in this setting.  Playing with your kids for a few hours(playing ball in the yard etc) is this defined as cardio? Does taking a leisurely stroll with a baby carriage for an hour or two?per day count as cardio? Or is cardio defined as something else?

Answer: I think you’re referring to the article I wrote on Why Big Caloric Deficits and and Lots of Activity Can Hurt Fat Loss, although I may have addressed the issue in a Q&A as well (I can’t find it).  In any case, your question is one that comes up fairly frequently, especially in the context of the Rapid Fat Loss Handbook approach (where I am adamant that excessive activity/cardio can cause the diet to work far less well than expected).  People want to know what and how much of certain types of activities will or won’t cause problems.

The primary issue here is this: the body appears to be sensing what researchers are calling energy availability, basically energy in (from food) versus energy out (via energy expenditure as discussed in detail in Metabolic Rate Overview).  And if energy availability becomes too low, often bad things (in metabolic terms) happen.  For example, researcher Ann Louckes has shown that many of the issues that often occur in women in terms of hormones or menstrual cycle dysfunction occur at a threshold of energy availability (and aren’t actually related to body fat percentage as used to be thought).

In that sense, pretty much all activity can potentially be a problem if that activity results in an energy availability to the body that is too low.  Of course the activities you’re listing aren’t really big calorie burners, a walk with a stroller probably only burns a few hundred calories per hour.  But done for extended periods it will contribute.

A related issue, and one I focused on more in Why Big Caloric Deficits and and Lots of Activity Can Hurt Fat Loss can be related to both intensity and volume.  In addition to hormonal issues, often the combination of big caloric deficits and excessive activity (either too much activity, too hard of activity, or the combination) can cause some real weirdness with water retention that masks fat loss.

I’d tend to say that this is more common with more formal ‘cardiovascular’ activities than just activities of daily living.  This is just due to the potential for increases in hormones like cortisol; this is especially an issue as the intensity of activity increases.  Clearly this isn’t an issue for a leisurely walk but it becomes more of one for more formal cardio activities.

This isn’t really stopping fat loss mind you, but it does drive people crazy because it makes it appear that the diet is not working.  I’d note that this isn’t an issue for everyone, certain physiologies (and especially psychologies) seem relatively more prone to problems with water retention than others.  This is why some people can get away with massive amounts of activity and not have issues and others can’t.

In any case, I hope that answers your question to at least some degree.

Why Big Caloric Deficits and Lots of Activity Can Hurt Fat Loss

This week, several people have brought a recent case-study to my attention and asked me for comment.  In it, a 51 year old female began marathon training along with a (self-reported) low calorie diet and either appears to have gained weight or not lost weight (she also showed a very depressed metabolic rate, nearly 30% below predicted).

By raising her calories gradually, her body fat (as measured by BIA) came down and her metabolic rate increased.  Now, without more details, it’s hard to really comment on this and the link to the case study is the total amount of information available.

But we’ve got an older (either post-menopausal or peri-menopausal) woman, undisclosed anti-depressant medication, self-reported food intake and a method of body fat measurement that is, at best, problematic (read Methods of Body Composition Measurement Part 2 for more details).  Odd things happen metabolically around menopause, some medications can cause issues, food reporting is notoriously inaccurate and BIA isn’t ideal to track changes.  Then again, the measured metabolic rate change is pretty interesting; something was going on.

That said, I’ve mentioned in previous articles that one oddity that I’ve seen (and personally experienced) over the years is one where the combination of very large caloric deficits and very large amounts of activity (especially higher-intensity activity) can cause problems for people either stalling or slowing fat loss.

Like my previous article on The LTDFLE, or Long-term Delayed Fat Loss Effect, this is one of those oddities that seems to crop up more often than you’d expect.  It’s also one where there’s not a ton of research but I will happily provide a good bit of speculation on what I think may be going on.
I’d also note that the combination of big caloric deficits and large amounts of activity clearly isn’t detrimental to everyone.  Some folks can get away with it but, for many, it tends to backfire more than anything else.

First, Some Background

Back in my early 20?s, I remember a very specific client I had.  She was a little bit, well, to be honest nuts.  She was older, I think she had gone through menopause but I wouldn’t swear to that.  In any case, she started working with me, determined to lose weight and immediately jumped into something like 2 hours of cardio per day and cut calories massively.  She claimed 600 calories per day and I won’t even try to describe her diet; it was insane (breakfast was supposedly one-half an egg and to this day I’m not entirely sure how you eat half an egg).

Now, I didn’t know much at that point but I had this general idea that too much activity and too few calories was a bad thing.  For weeks on end I entreated her to either cut her activity or raise her calories.  She adamantly refused; how could that possibly work?  I tried to point out that what she was doing wasn’t working either and she could hardly do worse by trying something different but that line of logic went nowhere.

In any event, at one point she went on a cruise or a vacation or something.  And what do you think she did?  Exercised less and ate more like everybody does on vacation.  And she came back something like 5 pounds lighter (some of which may very well have been The LTDFLE mind you).  “See, see.” I told her, “You ate more and exercised less and good things happened.”
And she immediately went back to a massive caloric deficit and over-exercising.  But that’s how it goes sometimes.

Later in my 20?s, mind you, I’d do the same thing during the now infamous Bodyopus experience (probably the singular experience that taught me what NOT to do during a fat loss diet).  Frustrated by stalled fat loss (I had dieted far too long at that point in the first place), I worked even harder, cutting calories further and adding more activity.  That coupled with some genuinely awful ‘carb-loads’ took fat loss to a standstill.

In addition to those case studies, this is a phenomenon that I’ve seen elsewhere including the support forum, I imagine readers run into it constantly: people (frequently but not always women) who try to combine excessive caloric deficits with massive amounts of activity (often with a lot of that activity being high-intensity activity) and nothing is happening.  And if you can get them to reduce activity (or just cut back the intensity to reasonable level) or increase calories, things invariably start to work better.

What’s Going On: Let’s Talk About Cortisol

Cortisol is one of those hormones that I imagine everyone reading this has heard about and about which a lot of misinformation exists.  Simply cortisol is a stress hormone, released by the body in response to nearly all kinds of stress.  In the fitness/bodybuilding world, cortisol has gotten an almost exclusively negative reputation (cortisol is ‘bad’ in the way that testosterone and thyroid are ‘good’) although this is simplistically incorrect.

Rather, whether cortisol does good things or bad things in the body depends on how it’s released.  Simply (and I’d simply, ha ha, refer folks to Robert Sapolsky’s amazing book Why Zebras Don’t Get Ulcers for a detailed look at this; I also talk about cortisol in The Stubborn Fat Solution), acute pulses of cortisol tend to do good things and be adaptive and chronic elevations in cortisol tend to be bad and be maladaptive.

For example, the morning cortisol pulse helps to promote fat mobilization.  In contrast, a chronic elevation of cortisol (especially in the face of high insulin levels) tend to promote visceral fat accumulation.  As a non-fitness related topic, acute pulses of cortisol tend to be good for memory (why we often remember stressful situations in such detail) while chronic elevations (as often seen in depression) make memory go down the toilet.  And there are endless other examples of where acute cortisol pulses are good and chronic elevations are bad; again see Sapolsky’s book for details.

In any case, dieting in general is a stress.  And of course training is a stress.  And the more extreme you do of each, the more of a stress occurs.  And I suspect that a lot of what is going on when folks try to combine excessive caloric deficits with massive amounts of activity is that cortisol just goes through the roof (there’s another issue I’ll come back to at the end that relates to this).  Simply, you get these massive chronic elevations in cortisol levels.

Tangentially, this is also one reason I suspect that various types of cyclical dieting help with some of this issue.  For at least brief periods, when calories are raised to maintenance or above, you break the diet/training induced elevations in cortisol.  This of course assumes that the person isn’t mentally stressed to the nines by raising calories like that but I’m getting ahead of myself.

So Why is This Bad?

As noted above, chronic elevations in cortisol can cause a lot of bad things to happen. One of them is simply water retention and I’ve mentioned in previous articles that water retention can mask fat loss, sometimes for extremely extended periods.  I talked about this in some detail in The LTDFLE and suspect that some of the ‘fat loss’ is actually just water loss when calories are raised and cortisol mediated water retention dissipates.  Reducing total training (volume, frequency, intensity or some combination) does the same thing.

But that’s probably not all of what’s going on.  Another effect of chronically elevated cortisol levels is leptin resistance in the brain.  I’m not going to talk about leptin endlessly here again, you can read the Bodyweight Regulation Series for more information.  When the normal leptin signal to the brain is blocked, a lot of things can go wrong metabolically and I suspect that this is part of the problem.

In this vein, although not necessarily related to cortisol per se, at least one study found that the addition of 6 hours per week of aerobic activity to a very low calorie diet (in this case a protein sparing modified fast) caused a larger decrement in metabolic rate than the diet alone.  The body appears to monitor caloric availability (simplistically caloric intake minus output) and if it gets too low, bad things can happen.

This is why I so strongly suggested AGAINST the inclusion of much cardio in The Rapid Fat Loss Handbook; it causes more harm than good.  Invariably, the biggest source of failure on that plan is when people ignore my advice and try to do a bunch of cardio.  And fat loss stops.

In any case, there are several different plausible mechanisms by which the combination of excessive caloric deficits an large amounts of activity can cause problems.  Whether it’s simply cortisol related water retention, a drop in metabolic rate due to leptin resistance or something else, something is going on.  From a more practical standpoint, for a lot of people, the combination simply doesn’t work.  Mind you, some seem to get away with it but not all.

An Additional Variable

There is another variable that I have noticed over the years in looking at this issue.  As odd as it sounds, it has to do with personality.  In discussing this, for example, I’ve often noted that the people who seem to have the biggest issues with the whole lots of cardio/big caloric deficit tend to be a little bit ‘tightly wound’ (to put it politely).  A bit less politely they are stress cases.

You can almost ‘hear’ the stress in their typing.  Every post has lots of exclamation points and there is this undercurrent of “I MUST LOSE FAT NOW!!!!!!”  in their posts. When fat loss stalls for a day, they freak out and want to cut calories or go add another hour of cardio.  You can almost ‘see’ the tension in them as they sit hammering at the keyboard looking for solutions.

And this is an issue because these types of folks already over-secrete cortisol.  As a true oddity, there is the issue of amenorrhea (loss of menstrual cycle).  Typically it’s been thought to be related to body fat levels or caloric intake and this is a general cause.  But there is often a type of amenorrhea seen in women without any of the normal predisposing factors.  In this case, it’s all due to mental stress.

Basically, there is a subset of folks who are already high-level stress cases. They tend to be drawn to harder is better in the first place, tend to be resistant to change (like my client from my early 20?s) and their already high level of cortisol production is simply amplified by the combination of too much activity and too few calories.  And suggestions to raise calories and/or reduce activity are invariably met by resistance (again, like my client from ages ago).  What they really need is to just chill the hell out.

But invariably the approach that they are intuitively drawn to is the wrong one for them: moderate deficits and moderate activity always work better in those folks.  It’s getting them to do it that’s the hard part.

Tangentially, I suspect that the classic hardgainer is of a typical type but that’s another topic for another day.

Summing Up

So that’s that, a look at one of the oddities of fat loss, the situation where the combination of excessive caloric deficits and excessive amounts of activity seem to hurt rather than help fat loss, along with some gross speculation (and just enough research to make it sound like I know what I’m talking about) on what may be going on.

In a practical sense, of course, most of the background isn’t that relevant.  The simple facts for the majority of folks is this: you can either cut calories hard OR do large amounts of activity.  But you can’t do both.  Well you can do both, you just probably shouldn’t under most circumstances.

AV Conclusion – So there is plenty of info for you to help you understand why cardio is not the best option. Click on any of the links if you want to learn more. My next post is on the serious problems from running marathons as well as addiction to cardio and some psychological issues related to the topic.. and I will definitely add more of my own colorful commentary.



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