Thursday, April 23, 2009

Nikhil Rao - What Your Doc Doesn't Know About Weightlifting

From T-Nation, Nikhil Rao tells you What Your Doc Doesn't Know About Weightlifting - and he's a resident in psychiatry studying the relationship between exercise and nutrition and mental health.

I've had some serious issues with doctors over the years.


"Creatine is a steroid." Excuse me, but you DO have a medical degree, yes? And you don't know that creatine is an amino acid complex? Uh, can I get a second opinion?

"There's nothing you can do to make a broken bone heal faster." Oh really? So all that healing and calcium accretion that has already occured as a result of weight bearing exercise is an illusion?

"Weight lifting is bad for your back." No shit? So why haven't I had any serious back injuries since I started doing deadlifts and squats, but before then I f**ked up my back big-time just picking up a magazine off the floor?

Anyway, I digress.
What Your Doc Doesn't Know About Weightlifting

Sir William Osler, the founder of modern medicine, once remarked that "The greater the ignorance, the greater the dogmatism."

It's kinda ironic, then, that the field of medicine is so ignorant—and so dogmatic—when it comes to exercise and nutrition. It's not hard to see where it comes from. Pride. Hubris even.

Medicine is one of the most demanding fields in the world. After 8 years of college and medical school, I'll be taking my Hippocratic oath in a couple of weeks. And then I still have 6 years of residency training ahead of me. Some of my classmates have even more. That's a lot of time, a lot of studying, and a lot of effort.

And the responsibility? Every day we make life or death decisions. Every time we examine a patient we have a chance to pick up—or miss—a sign or symptom of a disease that could take our patient's life or cause irreparable damage to their health. We are among the best and brightest, the most highly educated, and most influential people in the world. Hard not to let that go to your head.

Medicine is ultimately about authority and knowledge. We know more about the human body in health and disease, and hold more responsibility for it, than anyone else.

Contrast this with science, which is ultimately about ignorance. Science moves forward when we look to what we don't know, and try to figure it out.

Needless to say, finding ignorance is one of the most important lessons a scientist can learn. In fact, one could say that is the sole duty of a scientist. Doctors learn a lot about what science has revealed about the human body. But they aren't trained to be scientists, or to think like them. A doctor knows what he or she knows, and that's the end of it.

Doctors have a lot of opinions on diet and exercise. Weight training isn't healthy. Weight training hurts your heart. You'll destroy your joints. Squats are bad for the knees. Deadlifting is bad for the back. You should only do light weight and high reps. You're too heavy and will die of heart disease and diabetes unless you lose some weight. You're destroying your kidneys with all that protein. Creatine is bad for you. The only exercise you need is cardio.

I could go on for days. Most of us have heard it. A lot of us don't pay too much attention. Some of us do, and change the way we work out. And almost all of us wonder just how true these things are, if we really are destroying our bodies in the quest for strength and physical perfection. The real question is, how much attention should we pay to these experts?

Like I said, medical education is extremely intense, and extremely broad. It has to be. That said, there is a lot it doesn't cover. We learn the atomic structure of every amino acid (most of us promptly forget all of this after the biochemistry final). We learn the equations for cardiovascular physiology. We learn the branches of every nerve, the origin and attachment for every muscle in the human body.

But we don't learn the basics of healthy nutrition. We don't learn about cardiovascular and musculoskeletal adaptations and responses to exercise. We don't learn about how insulin facilitates the utilization of protein and creatine.

We don't even learn what all of those muscles in the body actually do. We don't learn about the difference between myofibrillar and sarcoplasmic hypertrophy. Or the training effect of high versus low reps.

Heck, most doctors aren't even aware of the concept of High Intensity Interval Training, let alone how much more effective it is than steady-state cardio.

And yet doctors think that their opinions on eating right and exercising actually matter. I honestly don't know whether to laugh or cry about it. All of those years of school, and everything I know about exercise and nutrition I had to teach myself. A lot of it coming from right here at TMUSCLE. And most of my colleagues don't see why I make such a big deal about it. There's nothing else to call it but pathetic.

What I'm hoping to do in this article, and possibly future ones, is deal with some of these issues where doctors have it all wrong; sometimes because of the field's ignorance about exercise physiology and nutrition, and sometimes because they don't understand the limits of their own knowledge.

The following are just a few examples of things they've got wrong.

Body Composition

Most of the guys on this website are 'overweight' or even 'obese' according to the BMI. There are a lot of dramatic studies out there about the health risks of being too heavy, from heart disease to stroke to cancer to dementia. I don't think that's a point of much contention. Being fat is bad for you.

The real question is whether or not the BMI is a decent tool for assessing how fat you are. It seems like every other time I go to the doctor's office he (or his nurse) brings up my BMI of 29 and suggests I lose weight.

Now, in the interest of full-disclosure, it's been a while since I saw the bottom two cans in my six-pack, and my love handles actually have names, but if it weren't for my gluteal muscles these 32" pants would fall right off. I'm pretty sure my 'borderline obesity' has more to do with the fact that I can barely stuff myself into a size 48-suit coat than it does a dangerous level of body fat.

When a well-muscled individual brings up this point, doctors often reply that "Okay, yeah, it doesn't work for people with a lot of muscle, but it works just fine for the general population."

Does it? Does it really??? I have my doubts. After all, the BMI consists of ONLY your height and your weight, and pretty much ignores everything else, like bones and lean body mass, which can be highly variable even within the so-called 'normal' population.

Some researchers at the Mayo Clinic had doubts of their own, with good reason as it turns out.(1) When they assessed the diagnostic performance of BMI using the World Health Organization reference standard 25% (body fat) for men and 35% for women, they found that only 36% percent of obese men actually had a BMI of over 30. The majority of people carrying around unhealthy amounts of fat actually had 'normal' or 'overweight' BMIs.

If that wasn't bad enough, it turns out that in people with a BMI of less than 30, it actually correlates better to lean body mass than it does body fat percentage. A study by a different group in Canada found similar results.(2)

So using the BMI doesn't work so well for the 'normal' population either. As if failing to identify two thirds of the people that need to lose weight weren't bad enough, this also means that literally decades of population studies on the health risks of obesity are also largely invalid.

Most people with a BMI over 30 are indeed 'obese'. But almost half of the population with a BMI less than 30 is also 'obese'. Which means most of these studies are drastically underestimating the health risks of obesity. This isn't so much of a concern for those of us in MMA, lighter weight classes, or mostly in it for physique. But for the powerlifters and strongmen out there who do carry around their fair share of adipose tissue, it means that those extra pounds are MORE dangerous than you or your doctor realize.

Lastly I want to touch on lean body mass. A lot of studies have found what many doctors think of as a 'paradoxical' effect in which people in the 'overweight' BMI range (25-29.9) actually tend to live longer, have less heart disease, be more likely to survive cancer, and have less disability.

Studies that have compared BMI to body fat and lean body mass have found that people in the 'overweight' range weren't necessarily any fatter than people in the so-called 'normal' range; rather, their extra mass came from lean tissue. So contrary to what your doctor says about all that extra muscle you're carrying around, your weight training is probably doing more for you than all that running is doing for a marathoner.

But that doesn't mean higher lean body mass doesn't have its downsides. Injuries come with the territory when you push yourself in the gym. That excess mass and the heavy weights do put more strain on your joints, although this is counterbalanced by the fact that your muscles bear more of the load and your connective tissue less. The more weight you carry around, the harder your heart has to work.

More muscle means a faster metabolism, and thus less chance of dementia, diabetes, and heart disease. But it also means more free radicals and potentially more inflammation, which means more stress on your endocrine system, cardiovascular system and brain, and possibly higher rates of cancer.

So is there a point of diminishing returns? Is there a point where you have 'too much' muscle? Probably. But because long-term population research has only used the BMI, we have no idea what point that is.

The BMI has outlived its usefulness. Not only in well-muscled individuals, but in everyone. You wouldn't let someone do stiff-legged deadlifts with locked knees and a round back, and you shouldn't let people judge their own health status and weight-loss goals based on BMI either.

Tell them to try a Tanita monitor, skinfold testing, or DEXA instead. Something this entrenched and this insidious needs to be attacked at every level by every person in the know. Spread the word.

High Blood Pressure

Hypertension is among the most common chronic diseases out there. And even though there aren't any symptoms, it can have devastating effects on your kidneys, your brain, and your heart.(3) Which is why it's called the 'silent killer'. And is one of the reasons your doctor almost always checks your blood pressure, regardless of the reason for your visit.

The medical profession is absolutely justified in the time, resources, and intensity with which we attack hypertension. But, like the BMI (although orders of magnitude better), our method of measuring blood pressure is less than perfect.

If you really do have high blood pressure, it's vital that you get it treated. But what if you don't? Whether it's the inconvenience, the cost, or the side effects, no one wants to take pills if they don't have to. A more pragmatic concern has to do with health insurance. In this era of medical underwriting and denial of coverage for pre-existing conditions, the last thing you want is for the label of 'hypertension' to follow you around in your medical charts for the rest of your life.

Back to blood pressure measurement. The only accurate way to measure blood pressure is to take a catheter with a pressure transducer on the tip and thread it up through an artery into your aorta. Not terribly convenient. Or fun. Which is why we use the blood pressure cuff.

In really sick patients, though, we often do monitor the blood pressure directly through a catheter. In my limited experience, novice physician that I am, most of the time the arm cuff agrees with the intra-arterial blood pressure measurement. But that isn't always the case.

Error can come from the cuff itself. Too small a cuff will give too high a reading. A standard cuff tops out at around 14-15" of arm circumference, conservatively. But most of the people we use the larger cuffs on are rather gifted in adiposity.

It often doesn't occur to health professionals that a lean arm can simply be too big for the cuff. Even when I tell them ahead of time that the regular cuff is too small, they'll often insist on trying it first.

Now in me, the regular cuff either completely fails to get a reading, or reads such an absurd pressure that they give up and get the large cuff. But in many, with a cuff slightly too small, it'll just give the kind of reading you'd expect in someone with hypertension. It's still a false positive. So if I were you, I'd ask for them to take a reading with the larger cuff if the regular cuff gives a high value.

The second problem comes from the fact that you've got muscle and fat surrounding that artery, so the reading on the cuff is actually a result of how the pressure gets transmitted from the artery through the fat and muscle.

Fat, being very compressible, can act like a sponge or a shock absorber, leading to falsely low measurements. In fact, I once had a patient that was so morbidly obese, no one in the office was able to get a blood pressure reading from the upper arm. We had to use the forearm. Muscle, on the other hand, is very firm, and can actually lead to higher than expected readings.

This is known as 'spurious systolic hypertension' (SSH).(4) In most people with high blood pressure, both the high (systolic) and low (diastolic) number are elevated (systolic >140 and diastolic >90).

Some people present with what's called 'isolated systolic hypertension' (ISH). In this condition, only the high number is elevated. Most commonly we see this in older people, and we think it's because their arteries aren't as elastic as they are in younger people, due to breakdown of the connective tissue calcium deposits in the walls of the arteries.

People with SSH tend to be young and have no major health risk factors (obesity, smoking, high cholesterol etc). In other words, nothing like the people we normally see ISH in. They tend to be different from normotensive people of the same age only in that they have a higher BMI and are more likely to engage in athletics.(5) SSH most likely has nothing to do with blood pressure and everything to do with the anatomy of a muscular individual's arm.

So if you're getting a high blood pressure reading, first check the cuff size, and then look at your diastolic number. If it's lower than 90, chances are you have SSH and don't need either the label of hypertension or a medication.

Kidney Function

It's common dogma among physicians that high protein diets are bad for your kidneys. Dr. Lowery here at TMUSCLE has beaten that idea pretty much to death recently.(6) So I won't get in to too much detail here on that. But the bottom line is that high protein intake may be harmful to your kidneys, and it may not be. We have literally no evidence to go on one way or the other. So your doctor pretty much doesn't have a leg to stand on when he tells you that you're killing your kidneys.

The notion that protein is harmful comes from studies of people with damaged kidneys—people with either chronic renal insufficiency (CRI) or chronic renal failure (CRF). In these people there's no doubt about it. The higher your protein intake, the faster your kidney disease is going to worsen.

It makes sense when you think about it. These are people whose kidneys can't even keep up with the basic demands their bodies place on them. Increasing the demand on the kidneys above that basal state can't possibly be good. But can we extend that principle to people with normal and healthy kidneys? There's no reason to think we can, and a lot of reasons to think we can't.

The kidneys are remarkably robust organs with a lot of excess capacity. In fact, you have to lose about 75% of the functioning units (nephrons) in your kidneys before we even see changes in your kidney function tests. And that doesn't even take into account the fact that the kidney can dramatically increase its filtration rate from the resting state in a healthy adult.

An analogous situation occurs with the heart. In a healthy adult, HIIT, or any kind of cardio for that matter, is good for your heart. But take someone with heart failure, or severe coronary artery disease. It's probably not a good idea for them to start running stair laps.

Heck, that's why all the ED drugs have disclaimers to ask your doctor if it's safe for you to have sex. If you take an already weakened heart and stress it, bad things can happen. But you don't see doctors recommending healthy people avoid exercise, do you?

Our next concern regarding kidneys is the blood tests doctors use to determine how well they're functioning. There are two numbers in particular we're interested in: Blood Urea Nitrogen (BUN) and blood creatinine (Cr).

BUN is a waste product of protein metabolism. Creatinine is a breakdown product from the creatine phosphate found in your muscles, heart and brain. Doctors normally check these values with a simple blood test, which tells them the concentration of each.

Here's where things get tricky—and where doctors can make wrong assumptions. The concentration of these substances in your blood is affected by multiple factors, only one of which is kidney function. BUN concentration changes with your hydration status (low when you're well-hydrated, high when your dehydrated).

It also changes in response to how much protein you're digesting and turning over. The more protein you take in, the higher your BUN is going to be.

Creatinine on the other hand is a lot more stable. It's produced at a relatively constant rate; higher or lower depending on how much muscle you have, due to the constant process of muscle breakdown and rebuilding.

As such, the concentration in your blood has a lot to do with how much lean body mass you have. That said, there are certain things that can make your creatinine spike. Severe infections or other stressors increase muscle breakdown as a consequence of the cortisol and inflammatory hormones coursing through your body. For the same reason, a particularly intense workout or competition can do the same thing.

There is a 'normal range' for each of these things. And people with blood levels of BUN and Cr that are outside of this range often do have kidney problems.

On the other hand, there are a heck of a lot of weight trainers that end up seeing abnormal values in their bloodwork, which can set them and their doctors to freaking out.

But these 'normal' ranges are based on the assumption that you're 'normal' when it comes to all of those other factors I just discussed. Higher protein intake means a higher BUN. Higher lean body mass means a higher blood Cr. Greater physical stressors (and consequent increase in creatine turnover) means a higher Cr. Do you think any of these factors apply to T-Men? Darn right they do.

So your blood test comes back and your renal function tests indicate a possible problem. The doctor calls you in a panic, telling you that you've murdered your kidneys with all that protein and creatine and you need to stop them now. What do you do?

Well, your doctor's just overextended himself. He actually has no clue how your kidneys are doing and neither do you. But it's okay, because we do have the tools to directly calculate how well your kidneys are working, we just don't use them very often.

But it's going to need a piss test. One heck of a piss test. Twenty-four hours' worth of pee in an opaque jug to be exact. You see, the only way to figure out if your kidneys are filtering waste products well enough is to see how much they're excreting. Seems like common sense, doesn't it?

What I would do is ask to do a direct creatinine clearance measurement. You're going to want to hold off on working out for a couple days—which will drop your creatine down to the basal level from simple muscle turnover—but I wouldn't stop taking protein and creatine.

After you've given your system time to clear out any possible stress-related increase in creatinine production, come back in for another blood test and to grab the jug. The lab will compare your blood concentration of Cr to the amount in your urine. This will tell us exactly how well the kidney is disposing of waste, and allow us to control for all those ways in which you're 'abnormal'.

Like I said, it could turn out that your kidneys really are in rough shape. But more than likely it's just the fact that you get more protein and have more muscle than most.


Einstein once remarked, "It is by no means an idle game if we become practiced in analyzing long-held commonplace concepts and showing the circumstances on which their justification and usefulness depend, and how they have grown up, individually, out of the givens of experience. Thus their excessive authority will be broken."

You wouldn't be here if you didn't take your health seriously. That, and your love of iron, makes you abnormal. Which means sometimes you won't fit the model other people use to judge you, whether it's figuring you for a mindless meathead or determining the state of your health.

It's important to understand the assumptions on which doctors base their thinking. Sometimes the assumptions make no sense at all (as with BMI) and at other times, you're just different enough from a 'normal' person that 'normal' methods just won't apply.


1. Romero-Corral A. et al. Accuracy of Body Mass Index in Diagnosing Obesity in the General Adult Population. International Journal of Obesity 2008. 32(6):959-966.

2. Kennedy AP et al. Comparison of the Classification of Obesity by BMI vs. Dual Energy X-ray Absorptiometry in the Newfoundland Population. Obesity 2009. Apr 9.

3. Chobanian AV et al. Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Hypertension 2003. 42:1206.

4. Hulsen HT et al. Spurious systolic hypertension in young adults; prevalence of high brachial systolic blood pressure and low central pressure and its determinants. Journal of Hypertension 2006. 24(6):1027-1032.

5.Krzesinski JM and Saint-Remy A. Spurious systolic hypertension in youth: what does it really mean in clinical practice? Journal of Hypertension 2006. 24(6):999-1001.

6. Lowery L. Inconvenient Truths: Protein, Health, and Strength Sports. TMUSCLE: Feb 17, 2009.

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