What is Strength?

Strong Man is Strong
Image by LOLren via Flickr

Everyone seems to agree that strength is a good thing.

Sports trainers claim that increasing your strength will allow you to run faster, jump higher, hit harder. Physical therapists will tell you that increasing strength in a certain muscle will cure back pain, knee pain, and hip pain.

Regardless of whether or not these claims have any merit, one thing I find interesting is that hardly anyone ever defines what they mean by strength. And that’s probably because it can be a very elusive concept to pin down.

For example, one of the dictionary definitions for strength is: “the state or quality or property of being strong.” Fair enough, but that is a circular definition that doesn’t tell us very much. Many strength coaches will provide similarly muddy definitions, usually implicitly.

So what is a good definition of strength?

How about this: strength is the ability to create muscular tension. That’s not a bad start, strength definitely seems to have something to do with muscular work. But this definition doesn’t say anything about whether the tension can create useful real world movements that we would consider to be an impressive display of strength. For example, someone might be able to create a huge amount of tension in their body while remaining completely still and not doing anything. Is that strong? Not in any practical sense.

Let’s consider some real world examples of feats that are commonly considered to require strength.

Check out Benedikt Magnusson. I love this guy’s style:

Very impressive. But is he as strong as this guy?

And as long as I’m inviting bar room debates along the lines of whether a tiger could beat up a lion, let’s also ask: who is stronger, someone who can clean and jerk 1.5 times his bodyweight, or someone who can bale hay all day long and come back and do it the next day? Who has stronger legs, Lance Armstrong or David Beckham? And how do we measure the leg strength of Haile Gebreselassie, a guy who is only 5′ 3 and 123 pounds soaking wet, but can run 26 miles in a row well under a five minute pace?

Of course these are all silly questions. (But strangely compelling!) One way to answer them might be to start defining different kinds of strength. So one guy has absolute strength, the other guy has power, one guy has strength endurance, etc. Experts have created many different categories of strength along these lines, distinguishing maximal strength from strength speed, from speed strength, from strength endurance from reactive strength. And then of course there’s eccentric, isometric and concentric strength.

But there are further complications to consider. Even within any one of these categories of strength, it’s real world application depends on many other variables, such as the angle of the joint, accurate direction of the resultant force, the positioning and movement of the other joints, postural control and balance, the ability to relax the antagonist muscles and recruit stabilizer muscles, maintenance of a focused mental state, the absence of pain, etc.

In fact, if we were to extend all the categories of strength to their logical conclusion and respect the true specificity of strength, we could simply say that great deadlifters have great lifting strength, that marathoners have long distance running strength, and that Tiger Woods has great golf ball hitting strength. But now we are right back to our circular definition, where we just say that strength is the quality of being able to do stuff that takes strength.

So what is strength?

I’m still not sure how to define it, but I know I like this quote that I found while doing some google searches on this subject. Here’s an excerpt from an excellent article by Chip Conrad:

If we define strength in the physical world as “force development” and acknowledge all the different degrees of force development, then we have a giant spectrum of strength, from the archetypical absolute maximal force development . . . to extreme endurance events … It is all force development, from the body generating as much force as possible at once (powerlifting, Olympic lifting, throwing cars off pinned loved ones, etc.) to low-level force development over a long duration (what is called “endurance,” and often treated as something different from “strength.”).

With such a spectrum of possibility, why is it that the average weight trainer works within the very limited prison of 6–10 or 8–12 reps with moderate speed and weight? . . .What about speed? Duration? Distance? The weight room isn’t just for the limited ideals of a bodybuilder.

Beyond physical strength, we hear of strength of spirit, strength of character, and strong morale, all of which should have definitions of their own since they are often talked about as vague but determined, admirable traits. Perhaps these are simply ways of overcoming obstacles, showing a “strength” that has little to do with mere physiology or muscle.

How about a small, simple definition for strength? Ability. To be strong is to have ability. In life, in the gym, and in relationships. The ability to overcome the physical, emotional, or subjective obstacles that hinder our progress as human beings. That is strength.

I like it!

What do you think? Let me know in the comments below.

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15 Responses to What is Strength?

  1. I like it. I have always stressed movement with my patients and clients. The ability to move is key to our health. I think it is the same coin of Mr. Conrad’s idea, just a different side. Movement often requires one to overcome physical, emotional and subjective obstacles. But to do so creates health, opportunity and quality of life.

  2. I think strength is an individual measure of one’s CAPABLE abilities that will evolve with practice of continuity . For instance an overweight person may could only walk for 5 mins. but with continuous practice that person can now walk for 10 mins. I guess, that would be more of a endurance strength.

    • April,

      Yep, that’s progressive overload. All methods of physical progress are pretty much the same. Challenge yourself, don’t get hurt, and then challenge yourself more next time. Simple but not easy.

  3. jeff hallere, feldenkrais trainer, wrote a great article on this topic a few years back “A new definition of strength”
    JH:”….. Exactly. Now, if I train myself in any exercise system, and I’m sloppy in the way I provide support for myself, all I will do is train muscles based on supporting myself the way I am accustomed to. Until I’m able to fluidly change from position to position, and use the entirety of all the surfaces of my body with clear intention, I would say that I’m not strong. I wouldn’t be able to completely access my own muscles, or use them fluidly for any activity. Core strengthening exercises will NOT change the dynamic pattern with which you engage the environment. You’ll continue to maintain the faulty support.

    Now eventually, you might have a particular body shape that is appealing to look at, but it’s not necessarily efficient. First of all, look at how many people go through these kinds of rigorous strength training regimens and end up with horrendous injuries. I’ve worked with many people who have ended up in my office as a result of taking these kinds of classes without understanding – or being able to feel, or attend to – where their base of support is coming from.

    The endless succession of core strengthening exercises won’t necessarily improve the way a person rides their horse. It won’t change their understanding of their own balance, or their sensitivity. It won’t change their internal environment that governs their ability to sense their position in space. It won’t give them a more refined sense of what the horse is doing. It won’t give them a sense of moving on their horse so their hands can be soft. Nor will it give them the ability to sense what the horse needs. ATM lessons can bring awareness to the sense of effort, so that athlete, rider and martial artist can free themselves of bad habits that interfere with true strength.”

  4. Todd –

    While Conrad’s more poetic definition of strength can be appealing, it doesn’t help us think clearly about the role of strength training. I think you had it right in the beginning:
    “…strength is the ability to create muscular tension”
    This is muscular strength and it is specific the muscle in question.

    The various activities you cited all require – to one degree or another – muscular tension from various muscles. These activities also all require a skill component. By skill I mean the ability to execute the movement efficiently (the way you define it). At any given level of skill, more strength is better. That’s why improving strength is universally helpful. Of course at any given time the nervous system may limit you the strength of particular muscles during particular movement. I conveniently swipe this issue under the skill rug.

    There is no method that I’m aware of of measuring the tension of the muscle directly, so we have to rely on various indirect methods to measure it. In powerlifing they use the squat, bench, deadlift. The Oly lifters have the C&J and the snatch. But those movements actually require a good amount of skill (Oly movements probably more so than the powerlifts). Also those movements require contribution from a number of muscles.

    I think simpler movements that requires almost no skill are better for measuring muscle strength. For example, a static hold, with a given load, of the elbow at 90 degrees flexion to measure the strength of the biceps. Of course, now we run into the issue of muscle fiber composition (slow twitch, fast twitch, etc). But overall I hope I am conveying my view clearly enough.

    I realize that this is an oversimplification, but that’s my general view of the issue. I am still trying to clarify this view. One thing that I can’t figure out is whether it’s possible to increase strength without increasing the number of muscle fibers. Is it possible to make the individual sarcomere contract harder so to speak or do you simply need more of them to be stronger?

    Strength training is unusual because it’s the one training mode where we want to focus on training the muscle, and not the movement. I think everyone should dedicate 10 minutes a week or so to build strength and spend the rest of the time learning to move better.

    Great post. Would love to hear more of your thoughts on the issue.

    • Geo,

      Great thoughts, I agree with much of what you said and have many of the same questions. Yes, Conrad’s definition is perhaps more poetic than useful. The problem is that it is so broad as to be a little meaningless. The common definitions of strength definitely need deconstruction but how do we reconstruct with a new definition that is a little less vague?

      The individual muscle fibers don’t learn to contract harder, as far as I know. Greater strength comes from contacting more fibers at one time or in a more coordinated sequence and timing with other fibers.

      As to your prescription for ten minutes of strength and the rest of the week for movement, I have used that from time to time.

  5. The definition given in this piece is excellent. I think is not just about muscular tension or fiber capacity. Personal character and emotional traits do enter the equation. All athletes know that without proper mind control, the body will not respond to its highest abilities, therefore, the definition of strength must include some aspect of mind control, not just muscular tension.

    Allow me to go out on a limb here for just a second. I instinctively want to introduce some concept of “yielding” to the definition of strength. Yielding meaning to “give way”, “elasticity, flexibility”. For example, in jujitsu and judo both practice the “hard and soft” techniques of the martial arts. Often the practitioners best technique to defeat an opponent is not a direct use of force, but to bend into the opponents weakness, allowing them to defeat themselves.

    The definition of strength may also include the ability to perceive correctly when to apply direct force (hard) and when to yield (soft) according to circumstance.

    Another example might be; if a small child makes me angry, it may take great strength of will, character and compassion to control my anger and yield to the annoyance rather than exert force upon the child. By yielding to the child’s immaturity I am practicing being strong.

  6. Not so much a definition, but for me the physical side of training/strength comes down to the maximum force, mobility and applied skills over a range of everyday movements as well as sport specific training etc.

    I tend to think of Strength endurance, static strength and flowing/moving strength.

    Dynamic/flowing strength would be all kinds of activities from running to swimming and martial arts, Yoga, rock climbing, football, circuit training etc.

    Strength endurance (rather than just endurance) would be carrying out loads beyond the normal (bodyweight) capacity for an extended duration. For example walking/hiking for several hours while carrying an extra 20-60 kgs on your body. Or doing heavy lifts combined with sprints (mimics a firefighter carrying a person out of a building, then having to run up stairs and do it again etc)

    Static strength would include being able to hold a heavy object in a stationary position for an extended period of time (like the iron cross lift), it would also include the maximum amount of force in pressing, pulling and resisting an external force applied. Imagine a giant wall moving towards you in some kind of Batman-esque deathtrap, that static strength applied would be standing still, muscles tense, resisting the force of the wall/death trap trying to crush you.

    These are just some examples to think about.

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