No man has a right to be an amateur in the matter of physical training. What a disgrace it is for a man to grow old without ever seeing the beauty and strength of which his body is capable.
As far as I know, the real Socrates never actually said that. The above quote is to be attributed to the Internet, paraphrasing Xenophon, paraphrasing Socrates. But the general sentiment that physical fitness is an important virtue seems to be widely held among the ancient greek intellectuals. For some people, that is enough. The gods have spoken, and the pious are busy pumping iron. The rest of us, good skeptical philosophers as we are, require an actual argument.
Socrates' primary argument for fitness, in the actual quote, was that men need to be ready to survive and excel in battle. Obviously this requirement is mostly obsolete for us, so we'll have to rethink the value of fitness.
First off, what do we mean by fitness? This is arbitrary, but my favourite formulation of fitness is General Physical Preparedness. "Preparedness" implies an external criteria, but I find it more useful to define fitness internally. GPP, as I take it, is your body being trained and maintained to within reasonable proximity of its genetic capability.
As an analogy, imagine your body as a machine, like a bicycle. The average person's body these days is like a badly maintained bicycle. The tires are a bit flatter than they should be, the grease in the bearings is getting old and dirty, there's dirt encrusted into the paint everywhere, little buildups of road grit and organic material are in the crevices in the drivetrain, the spokes on the wheels are out of true, the metal bits are rusted, the cables and bearings are loose and sloppy, the chain is a bit stiff, etc. A well maintained bike, on the other hand, isn't a different machine, and all the important parts are the same, but everything is shiny, within spec, clean, smooth, and working. If you are going for a bike ride, you can expect the maintained bicycle to perform to within its designed capacity, and not do anything weird. The badly maintained bicycle might get you across town, but at that point you are taking a calculated risk, and no longer relying on the competence of the designer.
The human body, like a bicycle, has a number of subsystems that can be tuned to within their designed capacity, or left to drift to an unmaintained and atrophied state. Unlike a bicycle, the human body is self maintaining; you don't have to clean the dirt out and keep it tuned yourself. But it's a horrible cheapskate, tuned for an environment where any unnecessary metabolic expenditure meant death. We are rich now, but the body hasn't got the memo, so to get it to keep itself in tune, we have to trick the system into valuing fitness maintenance more than it values food. This means resistance training; putting controlled stress on the body that the maintenance system can then repair and adapt to, so that it thinks the fitness will be useful.
So what particular subsystems and properties of the body need to be trained and maintained to put your body in a prepared state? Shamelessly lifting the Crossfit 10 areas of fitness:
- Endurance: The ability of body systems to gather, process, and deliver oxygen.
- Stamina: The ability of body systems to process, deliver, store, and utilize energy.
- Strength: The ability of a muscular unit, or combination of muscular units, to apply force.
- Flexibility: The ability to maximize the range of motion at a given joint.
- Power: The ability of a muscular unit, or combination of muscular units, to apply maximum force in minimum time.
- Speed: The ability to minimize the time cycle of a repeated movement.
- Coordination: The ability to combine several distinct movement patterns into a singular distinct movement.
- Agility: The ability to minimize transition time from one movement pattern to another.
- Balance: The ability to control the placement of the bodies center of gravity in relation to its support base.
- Accuracy: The ability to control movement in a given direction or at a given intensity.
This definition isn't perfect, but it's pretty good. If a virtuous bicycle is clean, pumped up, oiled, greased, tightened, and tuned, a virtuous human body is adapted in the above areas.
So how do we get there? There are varying levels of how seriously we can take maintenance of the body, but basically, regular physical activity that stresses the above systems to near their limits. Sports, commuting by bike, tossing stuff around with the guys, lifting heavy objects at the gym, specific training programs, etc.
For me personally, I train for Crossfit. I don't do actual Crossfit workouts very often, but I train with a coach for that kind of stuff. Olympic lifting, powerlifting, metabolic conditioning, etc etc. Training like this directly builds and maintains the above capabilities. Obviously this is expensive, and above and beyond what normal people would be wise to do. I do it because I like it, but even if I wasn't as into it, I'd be pushing in that direction. Again, why?
Before we tackle the question of value, let's look at the cost. What might motivate you not to lift?
The modern urban lifestyle does not challenge us physically. If we want to maintain fitness, that's entirely on us to emulate the primordial condition of regular harsh physical stress. This is expensive. This is time consuming. You need to eat a lot more. This is painful and psychologically hard.
Pain and hardship are the sort of reasons that convince most people not to do something. But are they really a good reasons? If the best argument against something is that it is psychologically hard, is that worth taking seriously? I don't think so. In fact, psychological difficulty is probably a plus, in that by pushing through it, we end up mentally stronger. We should cultivate grit, and as such, we should ignore psychological pain as a consideration.
So the best arguments against fitness basically come down to time spent, money spent, and additional food consumed to get fit. And to be fair, it's a nontrivial expense. One of the guys at my gym has groceries as his single largest expense.
So why spend that time and money to stay fit?
Physical fitness makes a lot of stuff easier. For example, last weekend I went canoe camping. Hauling around gear. Putting boats on top of cars. Paddling. Hiking. I also recently worked as an engineer in a lab. Lifting equipment. Moving around big barrels of chemicals. Etc. This stuff was easier because I was fit. Some of it I would not be able to do if I was out of shape. But I don't think this is a good enough benefit to justify the expense.
The doctors tell us that regular exercise to stay fit will keep us healthy, keep us from getting sick, and help us live longer. This makes sense; in our bicycle analogy, we would expect the well maintained bicycle not to wear out as fast, and have fewer weird problems. That's great and all, but again kind of begging the question. Why is "health" worth it? Is getting sick a little less often and feeling generally more capable worth all the time and money you will spend on it? Maybe, but I'm not going to claim it's sufficient to convince a skeptic.
More interesting is that being physically fit seems to have psychological effects. Presumably this is partially because the body increases testosterone in response to physical stress and adaptation, which changes our brains as well as our bodies. I think a major component, though, is in doing something hard and self-driven, and seeing the results. It changes how you perceive yourself; more confidence. It changes how you perceive others; more judgement. It changes how you see the world around you. We can see this in the data and observing the people around us; people who achieve virtue through hard work have saner and more independent worldviews. People who let themselves go tend to have a morally degenerate looter/moocher mentality. It follows that the hard work of physical maintenance is a solid defence against those forms of insanity. But now we are talking about maintenance of self, maintenance of sanity, and matters of who we are and what we want to be. This is a lot more subjective than stuff like health and ability. But I find it more compelling, too. If this effect isn't sufficient on it's own to motivate me, it's getting there.
Visible fitness affects how other people treat you. A well built man walking into a bar with a confident pose will turn heads and get people interested in associating with him in a way that an awkward skinnyfat will not. Ultimately I think that this is because fitness is a credible signal of virtue - the kind of things you'd like to associate yourself with. Let's think about it; to get fit you have to be conscientious and capable of hard work, physically and genetically healthy, and these days you need time and money. And once you're fit and strong, you're harder to kill more useful in general. People want to be allies, and don't want to be enemies, with that, so they treat you better. Whether we conceive of chasing fitness as hacking residual simian psychology or achieving real demonstrable virtue doesn't really matter; it works. Again this is near-sufficient to motivate me to lift.
Even if all of the above just mitigated the cost of fitness, the thing that ultimately pushes me over the edge is what I've been hinting at throughout. I feel that there's a moral obligation to maintain virtue, a major and salient component of which is physical fitness. If you don't even keep your equipment clean and well maintained, if you can't even manage yourself enough to stay fit, if you don't even lift, how can I take you seriously? How could I take myself seriously if I didn't? Therefore we lift.