One prominent  and controversial question in strength training circles: Is training strength and demonstrating strength the same thing or different things?  In other words, what’s the best way to build strength – by “demonstrating” it through heavy maximal lifts, explosive movements, and plain-ol’ ‘lifting stuff‘, or by ‘training it’ through more measured and precise means?

This is a huge waste of mental energy (better directed towards actually exercising).

To clarify what I mean, take a look at my foster kids’ handstand form:

For my convenience’s sake (l.-r.): Max, Shirley, Santa

Who would you say is the strongest?  Why?

Note the following observations:

• Santa has near perfect form (it’s only imperfect because she’d been holding the handstand for a minute waiting for her siblings to get into their handstands).  It’s safe to say she’s not only well-practiced at handstands, she’s strong for her size.
• Upper body wise, Shirley is the weakest in the upper body – you can see her arms beginning to give way to the weight of her torso and legs (alas, her leg falling forward makes this obvious).
• Max fell over a split second after this picture was taken.  And yet, he’d be the first one of the three I’d enlist to help me carry a Murphy bed up three flights of stairs.

Of course, it’s a trick question.  You can probably see what I’m getting at here.  Strength can be demonstrated.  But in order to be demonstrated:

1) You have to be able to demonstrate it (skill).

2) You need to have strength to demonstrate.

Pick a different skill (say, carrying a Murphy bed up three flights of stairs with a partner) and the evaluation changes.  Now, it’s clear who’s “strongest” – the only one capable of performing the task at all.

All this is mental piffle.  For actual exercise purposes, here’s what it boils down to:

The muscular/joint system has one global job: To move your body through space.  There is a near-infinite number of potential movements in which your body can be propelled (an infinite number of “skills”).  To effect the greatest change, choose those movements that are most global in scope (that effectively work the most muscle) and most applicable to your goals (after all,  a ballet dancer and your bocce ball-playing grandfather probably have markedly differing fitness goals) and apply measured, precise doses of exercise to improve the capacity of that muscle.

So it doesn’t matter if you lift a sandbag or a chrome-plated machine handle.  Work hard at increasing your ability; make it so that you can do more today than you could yesterday or yesteryear.  You’ll never master every skill known to man.  But you can make yourself a better version of yourself by mastering a few skills.  You even get to choose which skills they are.

Last night my foster son picked my brain regarding diabetes (his birth father is a Type 2 diabetic). While the entire car-ride conversation was ripe fodder for a blog post, what I’m going to recount here is our discussion on fatty liver, fructose, and diabetes.

What is fatty liver?

Fatty liver is an excess buildup of fat cells in your liver. When the liver becomes too fatty, inflammation occurs and liver function is compromised.

What does fatty liver have to do with diabetes?

They both are diseases of sugar metabolism. In Type 2 diabetes, your cells are insulin-resistant – they no longer respond to insulin’s attempts to pull sugar out of your bloodstream. In development of fatty liver, chronic high intake of fructose causes fatty deposits to develop in the liver.

Fructose?

Fructose is a type of sugar found in fruit (and in high fructose corn syrup, but we’ll get to this later). Chemically, it’s a simple sugar just like glucose but is metabolized differently. Glucose (and other sugars) are metabolized like this (courtesy University of Miami):

Fructose, however, follows a much shorter route:

Fructose—->Liver—->Fatty Acids

Ok, I’m dramatically oversimplifying the fructose pathway, but I want you to understand the “big picture” concept here. What happens with excess consumption of all carbohydrates is that they get repackaged as fat through a process called de novo lipogenesis.   However, there’s a limit to how much and how quickly sugar gets repackaged as fat – a rate-limiting step.

An analogy:  Imagine a FedEx shipping plant with a huge fleet of trucks and piles and piles of boxes to be shipped.  How quickly can you ship the packages?  The number of workers packing the trucks would be your rate-limiting step.  The boxes can only be delivered as quickly as the trucks are filled.  It doesn’t matter how large a fleet you have to deliver boxes with, without workers to pack them, the packages can only drip-drip-drip out of the plant.

The rate of sugar metabolism (see above complicated diagram) is bottlenecked by the regulatory enzyme phosphofructokinase.  Consume a ton of glucose, and what will eventually happen is that insulin rates rise, causing levels of leptin to rise, which limits your appetite.  No appetite = you stop flooding the system with sugar (but not before the damage is done).

Not so with fructose.  Fructose, that lucky dog, gets to skip that step.  Instead of having to be shuttled via the insulin pathway, fructose directly enters the liver and gets metabolized without this rate-limiting step.  So if you consume a lot of excess fructose, your liver synthesizes a lot of triglyceride (fat).  In fact, there’s practically no limit since insulin isn’t involved and thus your appetite won’t be blunted (recent research indicates that fructose effectively “shuts off” your appetite regulation).  So what happens?  Fatty deposits begin to show up in the liver (undelivered “packages” sitting around in the plant warehouse) – and over time, inflammation and liver cell damage occurs.  Continue this over time, and you’ve got the fertile breeding grounds for obesity and diabetes.

So does that mean if I eat fruit I’ll get diabetes?

It’s unlikely.  Remember, we’re talking about excess consumption of fructose.  Eat a bunch of fresh fruit, and you’re likely to consume 15-20 grams of fructose, tops.  But with industrialization of food and the addition of high fructose corn syrup as the primary sweetener used in food manufacturing, daily intake of fructose is nearly 4 times higher.  Think about all the possible sources of fructose – it’s in just about every sweetened drink you can think of: soda; fruit juices, iced tea, etc.  Moreover, sucrose (table sugar) is 50% fructose.  All that adds up to a considerable intake.

What it boils down to is that it’s easy to develop fatty liver (and diabetes) if you’re indiscriminate about what you eat and drink.  Avoid sweetened drinks high in high fructose corn syrup, stay away from sugar, and you’ll likely be fine.

Let’s offer a Cliffs Notes version of the above:

This great diagram from the American Liver Foundation (via msnbc.com) says it all:

As a general rule, sugar is bad for you.  But fructose is particularly bad.  So disregard what the food companies tell you and stay away.

The problem with being a know-it-all is that other people assume (not surprisingly) that you know it all.  Then, when a particularly bright (and well-researched) client says something like this:

I think modulation of the GLUT4 transporter is probably the key to the whole insulin sensitivity issue post exercise.  What do you think?

…you can only shrug your shoulders and say, “Gee, Gary, I don’t know…but I’ll get back to you on that.”

Have no idea what he was talking about?  Me either – until an hour ago.

What the heck is GLUT4 and why were we talking about it in the first place (read: killing time before the last exercise)?

First, some background.  You might recall me discussing the mechanism of insulin resistance, but here’s a quick catch-up:

Insulin functions to pull glucose (sugar) out of the bloodstream and into cells to be burned for energy or stored as glycogen (or to be stored as fat, if glycogen stores are already full).  Chronic high levels of insulin (caused by chronic high sugar intake) cause cells to become less responsive to insulin’s actions; in other words, cells stop responding to insulin and it becomes increasingly difficult to pull sugar out of the bloodstream and into the cells.  You body tries to compensate for this by increasing the amount of insulin (effectively “forcefeeding” sugar into the cells), but over time this strong-arming tactic grows less and less effective.  This process of insulin resistance eventually escalates into Type 2 Diabetes.

Conversely, being insulin sensitive is a good thing.  That means that it doesn’t require a whole mess of insulin to pull sugar out of your bloodstream.  Insulin sensitivity is strongly associated with longevity, which means you live longer if you’re more insulin sensitive.  Sounds good to me.

Ok, background established.  Now we’re about to wade into some deeper waters.  Tally ho!

Back to GLUT4:  GLUT4 is a sugar transporter protein that acts to “open the doors” for glucose (sugar) to enter cells.  There are 12 other sugar transport proteins, but the fourth isoform (GLUT4) is the main actor in glucose transport.

Let’s look at the insulin pathway a little more deeply here (thanks Wikipedia for a metabolic pathway diagram that isn’t intimidatingly offputting):

This diagram illustrates simply and clearly the process of glucose entering a cell.  Insulin binds to its receptor site and sets off a chemical cascade that activates GLUT4.  GLUT4 opens the doors, and glucose is allowed into the cell, where it meets one of three fates: Glycogenesis, glycolysis, or lipogenesis.

Straightforward and neat.  But there’s an exception: The post-workout period.

The post -workout period is special, because during this time, you’re as insulin sensitive as you can get (makes sense, since your body is attempting to replenish its fuel stores as quickly as possible during this period, let’s let as much glucose through the doors as is possible; fill ‘er up!).  Here’s a nifty fact:  The exaggerated insulin sensitivity occurs via GLUT4, and doesn’t require the action of insulin.  What this means is that you’re literally bulletproof (sugarproof?) in the post-workout period, until glycogen stores are full (all fuel tanks have been replenished.  After that point, even a little spurt of insulin is enough to shift you towards fat storage; since, where else are you going to store all this extra sugar?

So let’s distill that into Cliffs Notes:

You exercise, intensely.  By doing so you deplete muscle and liver glycogen (stored sugar), burning it for energy.  After exercise, you decide to eat a 5 pound bag of potatoes.  The starch in the potatoes gets broken down into its constituent parts, namely glucose – sugar.  GLUT4 opens the doors to your cells and the sugar flows in, refilling muscle and liver cells with glycogen.  At the same time, your insulin levels rise, since the goal is to get that glucose into the cells as fast as possible.  Insulin rises, more GLUT4 is activated, more doors are opened, and soon enough your glycogen stores are full.  All that leftover sugar?  Repackaged as fat.

This clarifies post-workout reuptake for me a lot.  And, it answers a question I’d had for some time:

Insulin spikes retard growth hormone release.  Growth hormone is required for synthesis of new (and repair of damaged) muscle tissue.  And yet, a mix of carbs and protein (not just any carbs either, but readily digestible – simple – carbs) seems to work best in both replenishing muscle glycogen and in stimulating muscle tissue synthesis.  What gives?

Now I know what gives – GLUT4 allows for glucose influx independent of insulin.  So I guess you’re right, Gary.

Every once in awhile (ok, well; often) a client will pass along a news story that’s so far off the mark that it makes me go Super Saiyan.  Here’s the latest one:

Cereal and Milk is the New Sports Supplement, Says Study.

Briefly, the new study looked at using a whole foods source – in this case, skim milk and Wheaties – to replenish muscle glycogen vs. a sport drink (probably Gatorade – the full study is available here).  The end result?  Milk and cereal worked just as well to replenish muscle glcoygen and even better at promoting protein synthesis than the sports drink.  In other words, Wheaties builds more muscle and refuels your muscles just as well as Gatorade (!).  So we should all be having a bowl of Wheaties after our workouts, then; right?

Yeah, not so much.

Let’s break this down in a science-y way:

We know from years and years of research that ingestion of carbohydrates post-workout speeds refueling of muscles by supplying muscles with the very fuel they need – glycogen (sugar).  Both the Gatorade and the Wheaties contain carbohydrate; hence they both work well to replenish muscle glycogen stores.  No mystery there.

Now the issue of protein synthesis (read: building muscle): We know from Jeff Volek’s research that ingestion of carbohydrate alone actually retards protein synthesis – it results in a net negative nitrogen balance – while a combination of protein and carbs accelerates protein synthesis.  Cereal and milk contains some protein along with copious amounts of carbohydrate; hence it worked to build muscle better than the Gatorade.  Mystery solved.

I applaud Dr. Kammer’s efforts to promote eating real foods as opposed to food supplements.  Where the problem lies is in making the mental leap in saying that you should have cereal and milk as your post-workout nutrition.  Yeah, it contains (scant) protein – but what about all that carbohydrate?  Why not, say, eggs and fruit?  Or chicken and a sweet potato?  Or a post-workout shake a la John Berardi with 2 parts carbohydrate to each 1 part protein?  Why skim milk and Wheaties?

Oh, because the study was sponsored by General Mills.

Why does this ruffle my feathers so?

1. News outlets consistently misreport the latest food findings.  They either distort the findings to make them more newsworthy (creating an unnecessary confusing maze of nutrition for the layperson) or flat out get it wrong.

2. It’s dreadfully difficult to get most people to eat enough protein.  If they aren’t worried about the purported (false) health risks of consuming meat, they (incorrectly) think that eating a salad with one chicken breast  is “enough protein.”  By the way, please don’t be this person.

Here’s an alternative: Tell people to eat a mix of protein and carbohydrates after exercise (and how much).  They’re smart; they can figure things out on their own.

One of the key concepts that I’ve tried to use in my application of Brazilian Jiujitsu is the idea of misalignment.  If you’ve ever partaken in an organized sport of any kind, you’ve probably heard the phrase, “Where the head goes, the body follows.”  Well, the converse is true as well – if you want to prevent your opponent from going somewhere (say, into a position where he can mount some kind of offense), push his head away from that area.

Why this strategy works so well conveniently relates to exercise thusly:  If your spine is in neutral position, it’s strong.  If it isn’t in neutral, it’s not.

Think of it this way:  Strip the spine of the surrounding musculature and connective tissue, and you’re left with nothing more than a stack of bottlecaps (studies have found that an unsupported spine topples under a load equivalent to a can of Coke).  While the connective tissue (ligaments, fascia, etc.) do hold the vertebrae together, it’s the spinal musculature that stabilize the spine and give the spine its strength.

Earlier, I discussed how changing the angle of pull of a muscle can expose a joint to dangerous amounts of force.  Well, the same is true for the spine.  When loading the spine, you must keep it in neutral (or attempt to keep it in neutral as best you can).  This insures that the spinal musculature are in the optimal position to do their job – to stabilize and protect the spine.

What does this mean for you?  Here’s a short list of “don’ts” to apply to your training:

1) Don’t twist, arch, or fling your head and neck around during a lift.

2) Don’t let your shoulders droop forward, since this pulls your upper back downwards.  Instead, keep your shoulders pinched back and pushed down (retracted and depressed).

3) Don’t tap dance, i.e., pick up and shuffle your feet during a lift (usually upper body).  You can’t tap dance and actively stabilize your lower body and spine at the same time.

In other words, don’t do anything that brings your spine out of neutral position.  Don’t misalign yourself.

Phyllis asks:

…but why do my shoulders keep popping up? If I know what the proper form is supposed to be, then why do I keep doing the same thing wrong? It’s not like I’m trying to do the exercise in bad form, it’s like they have a mind of their own.

The short answer: Your body is primed for efficiency, not effectiveness. By efficiency, I mean in terms of utilization of energy.

What does this mean to you with regards to movement?  Two things:

1. The same exercise load will become less and less “expensive” metabolically as you get fitter.  In other words, you burn fewer calories each time you do the same thing over and over again.  Sorry.

2. Your body will always look for the path of least resistance (i.e., the most energy efficient path).  This likely isn’t the path of greatest effectiveness (i.e., the path in which you are capable of lifting the most weight/doing the most work).

This harkens back to our primordial days as cavemen and women. Food wasn’t available at the local supermart down the block; it had to be hunted (and killed and cleaned and cooked), gathered, or farmed. In other words, there was an energy cost to obtaining food. If the goal is survival, then conservation of resources is key. If you expended more energy to obtain food than the food gave you back, then you’d surely starve to death. It doesn’t make much sense to expend more energy to gather food (or to do anything else, such as lifting a rock or a tiger, for that matter) than is absolutely necessary.

Back to the weight room:  What we’re interested in doing is as much mechanical work* as possible.  To do this most effectively requires technique, most of which involves using a great deal of energy.  Your body, interested in conservation of energy, looks to find the path of least resistance, which often involves bringing you out of ideal form (almost as if your body is trying to slink away or slide around the resistance) – mystery solved.

In this case, use your intellect and ignore your instincts.

*Mea culpa to Fred, Bill, et al:  Yes, yes, I’ll talk about metabolic work in a future post.

Ah, the muscle pump – in the annals of bodybuilding, is anything more sacred?  For the uninitiated, the pump is that sensation of muscle fullness after performing a lot of work for a given muscle group (whether directly or indirectly).

Ah, who am I kidding.  Everyone knows Arnold explained it best, way back in ‘77:

Of course, if you mention “Arnold” and “muscle pumps” in the same sentence, it’s usually this clip from Pumping Iron that springs to mind:

So we know bodybuilders like muscle pumps. But there’s an implied significance attached to achieving a pump that even casual exercisers know. It just instinctively feels ‘right to do.’

But does the pump deserve its vaunted status? Just what’s going on physiologically that causes a pump? And is it even necessary to achieve a pump to make good gains?

The pump is a traffic jam. (Warning: Boring science ahead)  What’s the mechanism that causes a pump?  Would you believe it’s nothing more exciting than osmosis?  Most trainers in the know dismiss the pump as mere fluid buildup, and on a macro scale, they’re right. Here’s what’s happening, in science-speak:

You’re embroiled in a difficult set, your muscle tissue is screaming for more energy (read: glycogen), and hydrogen ions are building up inside muscle cells (using that familiar burning sensation).  Blood rushes into the capillaries surrounding muscle cells and fluid and nutrients (oxygen, etc.) diffuse from the capillaries into the muscle cell.  On the other end, fluid (minus nutrients) exits the muscle cell by diffusing back into capillaries (osmosis).  When the hydrostatic pressure pushing fluid into the cell is greater than the osmotic pressure pushing fluid out of the cell, fluid builds up and a pump occurs.

Here’s the rub: The mechanism pushing fluid in is much more effective than the mechanism pushing fluid out.  In freeway terms, it’s a 6-lane highway entering the muscle cell, but a 1-lane street exiting the cell.  The end result?  The muscle pump – the body’s version of a traffic jam.  And just like all traffic jams, they eventually clear; pumps only last about an hour or two, and as fluid concentrations in the cell return to normal, cell volume too retreats back to normal.

What possible effect could this have on improved muscle growth? Only one, really: The “traffic jam” briefly results in a higher concentration of lactic acid, which has been shown in studies to correlate to growth hormone release (more lactic acid = more growth hormone).  Since growth hormone is a key hormone in muscle recovery (and consequently, hypertrophy), this premise shows some merit.

What does the science have to say about muscle pumps and hypertrophy (muscle growth)? Surprisingly little.  While some studies have shown a relationship between flow restriction and hypertrophy, it’s worth noting that they induced this flow restriction by literally occluding blood vessels (i.e., they wrapped an inflatable sleeve around the subject’s arm and cut off blood supply a la taking your blood pressure).   Even the researchers don’t agree on what exactly causes the muscle-building effects seen in the studies – one theory is that the occlusion of blood vessels results in greater mechanical load on muscle fibers (and we know that increased load results in greater muscle growth).  Whether or not all this translates into “pumps stimulate growth” depends on how liberally you read into the literature (and if you believe that a pump is occluding blood vessels to the same degree as a inflated sleeve cuff).

It’s also instructive to note there’s an alternative method to increase load on muscle cells – lift something heavier.

What about all the anecdotal evidence? Bodybuilders, who are the biggest (muscular) beings on the planet, prize the pump above all else, workout wise. Surely they’re onto something. Until you look at other populations of muscular athletes: Olympic weightlifters, powerlifters, gymnasts, sprinters; one black swan is usually enough to derail a theory.

But back to bodybuilding. One thing you may have failed to consider: The pump didn’t magically appear because you thought about it. Nor (generally) did it result from one workbout. It takes a lot of work to achieve a pump. So perhaps it’s not that the pump triggers anything special; it’s the work required to achieve the pump that’s the magic formula.

Certainly gymnasts work hard, fairly often.  Oly lifters too. Powerlifters can frighten small children with their training ferocity.

Hard work, the magic formula. Imagine that.

There’s no need to hit your arms with dumbbells, exotic bars, and cables from all different angles until you dislocate your aorta trying to achieve an incredible biceps pump.  It’s safe to say you can stimulate muscle growth without it.

Try this experiment: Grab a piece of rope, hold one end with both hands, and pull.

What happened?  A whole lotta nothing.  Why?  Because you can only transfer force through the rope if the other end is tied to something.  In other words, you can’t play tug of war with yourself.

According to our best theoretical model, muscles contract when their component parts slide in towards one another -  when muscles shorten they pull on both ends.

Take a look at this picture of biceps brachii:

When the biceps contracts, what does it do?  Most people say, flex the elbow, and they’d be right.  But that’s not all – it also flexes the shoulder (raises your arm).  And in fact, it can do both at the same time.  What’s different in each case is which end of the muscle is fixed.  When flexing the elbow, the shoulder end of the biceps is fixed, so when the biceps shortens, it moves the forearm.  When flexing the shoulder, the shortening fibers pull the entire arm up over your head.

It all depends on where your rope is tied and which end you pull from.

What does this mean to you?  That stabilization matters.  Here’s something else to consider: All exercises – open-chain, closed-chain, or lifting chains – involve stabilization of your torso (and likely, stabilization of your limbs).

“Anchor yourself” when lifting a weight, and you’ll be able to lift it better.  And lifting more weight better is the name of the game.

Two quick examples:

When performing a bench press or chest press, stabilize your shoulders by pulling them down and slightly back. By activating your lats and upper back muscles, you simulaneously increase your pushing power and decrease your chances of injuring your rotator cuff muscles.

Tighten your abs when performing a lat pulldown. If you’re using an apparatus that has a seatbelt, actively push your hips into the belt (performing a reverse crunch into the belt, essentially); this will better anchor your torso and give you more stability when pulling with your arms/lats/serratus.

A note, especially to beginners:  “Anchoring” your muscles will make the exercise feel a lot harder.  This is because more of your energy is focused on directly resisting the weight (i.e., performing the task) instead of merely “working.”  Notice that although the exercise feels “harder”, the weight feels easier.  You should feel the sensation of a stronger push.

In the previous post, I alluded to the terms neurological efficiency and neurological recruitment.  These terms sound similar but are quite different, not in the least in that neurological efficiency cannot be improved, whereas recruitment can be improved.  Consider this post an attempt to clear up confusion.

Both terms refer to what goes on in a muscle and its corresponding motor units.  Skeletal muscles are voluntary; in other words, you can will them to contract and relax (try doing that to the smooth muscle in your intestines).  Something has to carry the signal to contract from your brain to the muscle, and that something is the motor unit.  The impulse to contract goes from your brain, into the motor neuron, through the axon, and finally into the muscle fiber(s), the end result being contraction of those muscle fibers.

It’s probably clearer to show a diagram, so here ya go:

It may come as a surprise to you that you can’t really contract every single muscle fiber you have in your body all at the same time (not under “normal” conditions, anyway).  Neurological efficiency is the ability to contract a percentage of a given pool of muscle fibers. Neurological recruitment, however, is the ability to activate a greater number of individual motor units.

Say you have 100 muscle fibers in your biceps brachii muscle, activated by one particular motor neuron.  Someone with poorer neurological efficiency might only be able to contract 40% of the available fibers in any one contraction.  Someone with better neurological efficiency might be able to contract 80% of their available fibers.

Here’s where it gets a little murky – imagine now that the aforementioned 100 fibers was part of just one motor unit, and you had 5 motor units feeding your biceps (500 total fibers).  An untrained person might only be able to activate 3 of those 5 motor units at any given time (giving him a potential of 300 fibers working together), whereas a trained person might be able to activate all 5 (giving her a potential of 500 fibers working together).

Of course, the math gets complicated when you combine neurological efficiency and recruitment.  In the above examples, let’s assume the untrained guy is neurologically efficient (80%), and the trained female is neurologically inefficient (40%):

Untrained male = 300 x .8 = 240 fibers contracting with any one impulse

Trained female = 500 x .4 = 200 fibers contracting with any one impulse

Keep in mind these are just made up numbers to help illustrate the point; no athlete is out having his or her neurological efficiency tested.

An analogy:  Imagine a kiddie pool filled with water, and you’ve the task of emptying it out with a bucket.  You’re holding a 5 Gallon Home Depot bucket.  The bucket correlates to neurological efficiency – no matter what, you’ll can’t purge any more than 5 gallons with any one bail.  Neurological recruitment correlates to number of buckets – you can increase the amount you bail by simply increasing the number of buckets you use at any one time (using 4 buckets simultaneously being quite the sight).

Since most coaches and trainers like to focus on things you can actually change, the main focus in exercise science is on improving recruitment.  And that can be done through consistent, hard training.  Neurological efficiency is genetic and unchangeable, and (understandibly) ignored.

Teri asks:

I have larger hip muscles than Joanne.  So why is it that she can lift more than I can in lower body exercises?

It may surprise you to discover that there are lots of factors that determine strength (or, more accurately, expression of strength).  Here’s a quick and dirty list compiled off the top of my head, and you can almost bet that it isn’t exhaustive:

• Cross-sectional diameter
• Neurological efficiency
• Tendon length
• Tendon attachment point
• Limb (bone) length
• Technique*

*I hasten to add that “technique” is more a factor that influences expression of strength, as opposed to “strength” proper.  So why is it listed?  Because you can’t really quantify strength without expressing it (i.e., you can’t test strength without lifting something).

It might be due to one or more of the listed factors (and perhaps, all of them) that a person with smaller muscles can outlift a person with larger muscles (in Joanne and Teri’s case, it’s probably 2, 3, and 5).

You’ll note that of the factors listed, only two are factors you can change: Cross-sectional diameter (aka muscle size) and technique.  So it’s not worth worrying about the others, nor is it worth fretting over how much you can lift vs. how much someone else can lift (unless, of course, you’re facing them in a powerlifting meet).  Instead, place a high emphasis on progression:

• How much can you lift today?
• How does it compare to what you lifted last week?  Last year?
• How much (more, I hope) will you be lifting next month?

It’s fun to see how you stack up against others – the entire human race would wither away if we didn’t have that primal urge to be king or queen of the pack – but ultimately, physical fitness (and everything that term means to you) is a solitary affair.  The only person you’re racing with is yourself.

Edit (12/17/08): Samantha adds two more changable factors that influence strength: Fat levels (more fat = more leverage) and recruitment (note: This is different from neural efficiency.  I’ll explain in the next post).