by E. Paul Zehr
There may also be an interesting link between sleep deprivation and sleep regulation and metabolism (think back to Chapter 6). While we are awake we have the expression of certain genes that affect and modify the activity of our mitochondria and the movement of glucose around the body. Genes for key regulatory enzymes that can affect the levels of hormones and neurotransmitters in the brain are changed depending on the how long we are awake and when we are awake. So, in many ways sleep deprivation is a kind of stress or challenge to homeostasis and metabolism.
Let us turn now to chronic sleep loss. Recall that we found out previously that night shift workers may sleep during days on average two hours less than they would if they were allowed nighttime sleep. Well, that kind of situation means that over the long term a night shift worker like Batman is going to be incurring a chronic sleep loss and sleep “debt.” Some really interesting information on this issue has come from ultra-endurance races and military operations.
What is sleep debt? There is obviously a huge range for actual hours of sleep needed per night for different people, but the typical range is between about 5 and 10 hours. Athletes often sleep more than regular Joes and Janes. However, you can read in a panel from the “The Sleep of Reason” (Detective Comics #598, 1989) that Batman “barely sleeps.” Recall the quote at the beginning of this chapter about Bruce Wayne and sleep. In “The Sleep of Reason” it is stated that “with sufficient practice, the body can be trained—the muscles relaxed, the heartbeat slowed—so that one hour’s sleep does the work of eight.”
Well, this is certainly a time when the Batman universe is not at all realistic! Batman and Bruce Wayne do need to sleep. And there isn’t a kind of sleep efficiency training that could allow one hour to do the work of eight. I think I hear you asking why not. So, why not? Why is sleep even necessary in the first place?
In That Sleep . . . What Dreams May Come
I paraphrase the Bard a bit with that heading, but while questioning and raising the specter of nightmares during sleep one thing Shakespeare did not question was that sleep was necessary. However, an issue we haven’t even discussed is why we need to sleep. I will cut straight to the chase here and admit that sleep itself remains quite poorly understood in science. To borrow and paraphrase from a Winston Churchill radio broadcast in October of 1939, I think sleep can be considered as “a riddle, wrapped in a mystery, inside an enigma.” What is the additional advantage of sleep over and above just getting rest? Many animals don’t seem to need sleep. One thing is very clear, though: even if we don’t understand exactly why we need sleep, we die if we don’t get it. In fact, many features of sustained sleep deprivation have a great deal in common with the stress syndrome we originally discussed with regard to Hans Seyle back in Chapter 1.
Before answering the trickier question of why we need sleep, let’s explore something a bit simpler by first asking, on a basic physiological level just how much sleep do we really need? One quick way to get a superficial answer to this is to think about what happens to us when we don’t have sleep at all or when we aren’t getting anywhere near enough sleep. As we found out a few pages back, our inherent circadian rhythms lead to daily fluctuations in many different systems that in turn cause changes in alertness, reaction time, and so on.
Let’s continue our discussion of how essential sleep is by looking at what happens when people are sleep deprived. This kind of thing has been studied in laboratory and real-life situations. Incredibly, people can perform one hundred hours—I will do the math and tell you that is more than four days—of nonstop moderate intensity exercise if food energy is provided. However, despite being able to keep doing exercise, things like reaction time are really impaired. Indeed, “impaired” is the absolutely correct word to use for performance when sleep is withheld, because it links to the idea of alcohol impairment. Have a look at Figure 12.5 to see what I mean. As we all know, performance capacity drops as alcohol concentration in the blood is increased. On the top of the figure in panel A this predicted drop in performance with increased blood alcohol concentration is shown. Immediately below that in panel B performance over time of wakefulness (literally how long you have been awake) is shown. It is pretty clear that no major problems or decrements are seen until around 16 or 17 hours of wakefulness. Within a very normal range of waking, then, performance is maintained pretty well. However, once we reach 24 hours of wakefulness, severe decrements are seen.
If you match up the valley between 24 and 27 hours with the blood alcohol concentration in panel A, you will see that staying up for a full day can lead to performance impairments equivalent to about 0.08% blood alcohol concentration. Stated another way, it would be as if Bruce Wayne took five drinks and then attempted to drive the Batmobile! In fact sleep-related accidents in motor vehicles tend to cluster between the hours of 2:00 and 6:00 a.m., when drivers may either be up late or just getting up. In either case, these times are quite near the lowest ebb of performance and occur near the minimum body temperature.
In another real-world example, military personnel can often operate in conditions of sleep deprivation for several days. In those cases, significant issues arise after 36 hours of no sleep. These include extreme fatigue and problems with accuracy during rifle shooting. In most cases there is a relation between the performance and the circadian rise and fall of hormones such as adrenaline and noradrenaline. Clearly, complete sleep deprivation creates many problems. It isn’t very representative of the normal work environment for most people, though, including Batman.
Let’s now look at what scientists believe may be the reasons that we need sleep. Most physiological adaptations have what is known as “survival value.” That is, they provide or provided some form of evolutionary advantage and therefore were traits passed on to following generations. Some see sleep as one of those items that provided benefits at one point in evolution as a way to understand its role. Arguments related to the “need for sleep” have very often been based on several themes. The most compelling is that animals involved in long-term sleep deprivation experiments die. This is likely due to a process very similar to Seyle’s original stress and the last (and failing) stage of the generalized adaptation syndrome. A related argument involves the kind of observations we discussed above, where cognitive and motor performances are decreased even in short-term sleep deprivation.
Figure 12.5. Similar effects of blood alcohol (A) and extreme wakefulness (B) on performance. Courtesy Rajaratnam and Arendt (2001).
Note that there is a difference between sleep and rest. We often appear to be resting while we sleep but we can also rest without sleeping. What is the difference? Rest is really a period of low metabolic activity and can be seen in all animals, both warm-and cold-blooded. The term “sleep” is often used only for mammals and birds. Birds, which do sleep, can go for excessively long periods without sleep during long migrations and during times of incubation and hatching. A good example of this, because it conjures up one of Batman’s key foes, is that of the king penguin. During the incubation and posthatching period, the king penguin may be called on to defend his territory thousands of times per day! Clearly, very little sleep can occur with such demands. Yet the king penguin survives and flourishes.
So, why does Batman need sleep? We just don’t know for sure right now. All we can say is he does and that he is also chronically sleep deprived. However, he muddles along as best as he can just like most of us!
Now we’ve seen how Batman has protected himself with training and his batsuit and how he attempts to subsist with little sleep. Let’s turn our attention to what happens to Batman when he is not in peak performance and even gets injured.
PART V
A MIXED BATBAG
Pondering possible pitfalls along
the path to bathood
CHAPTER 13
Injury and Recovery
HOW MUCH BANGING
UNTIL THE BATBACK
GOES BONK?
Years of rigorous athletic train
ing have enabled the Batman not only to resist but to recover from the brutal beating that would have mortally injured most men!
—“Professor Strange’s Fear Dust” (Detective Comics #46, 1940)
Have you ever had a back strain that seemed to be brought on by the mildest thing? If not, you probably have heard somebody say, “I threw my back out just lifting up the milk at breakfast time.” Even professional athletes experience such injuries. When we subsequently read that a powerful man playing a rough sport like ice hockey or football hurt himself getting out of his car, we may have difficulty imagining that such a trivial-seeming event could lead to injury. But it can and does happen regularly. Every time we do anything we subject our muscles, bones, and other tissues to stress and strain.
Our biological tissues are just like many other materials, and over time they can weaken. Think of the old-style metal coat hangers. When I was a kid we were constantly using coat hangers to make all kinds of things—including awesome marshmallow-toasting forks! To do so usually meant unfolding the coat hanger and then breaking it in half. Except we didn’t break it with a wire cutter or any tool. Instead we bent the hanger back and forth over and over again until it heated up and then snapped in two. What we were doing is a bit like the way your tissues are repeatedly put through their paces by all your activities. However, your body is constantly rebuilding itself, unlike the stress and strain of that coat hanger or the head of your golf club when you take much too large of a divot.
Despite the ongoing repairs, small little things can really be the proverbial “last straw that broke the camel’s back.” So, Batman is constantly straining his body at the best of times and constantly getting really pummeled at the worst of times. What can his (or your) body take before injury occurs and how long does it take to recover from those injuries? For somebody as busy as Batman, there may be some injuries from which he never recovers fully. In “The Autobiography of Bruce Wayne” (The Brave and the Bold #197, 1983), Batman’s body really shows wear and tear. He has loads of scar tissue, as noted by Catwoman (who was cooperating with him in this story), who stares at his back and says, “It’s just . . . all this . . . scar tissue on your back . . .” In Batman’s own words “Oh, that. Occupational hazard. Fifteen years of fighting will do that to a person.”
Batman’s back is not the only part of him to get injured. Batman also takes a lot of blows to his head and pretty much anywhere else we can imagine. While trying to imagine the sort of occupational injuries that Batman might experience, let’s start with examples of other activities that could be considered similar to the main physical demands Batman faces on the job.
Occupational Dangers of the Dark Knight
To give an overview of what we could expect, I will describe injuries in two categories—one for brain and one for body—as concussions and strains. In talking about these categories we’ll focus on bumps to the head (concussion) and things like whiplash injuries (for strains). Batman really does find himself in very rough and physical encounters on seemingly a daily basis. It probably goes without saying that fighting Killer Croc (crazed maniac with unique “armor-like” skin disease), Blockbuster (crazed gigantic mountain man) and Bane (crazed humungous adrenaline junky experimental soldier) are not safe activities. The most dangerous foe that Batman has ever faced must be Bane. My stating this is largely due to the grievous injuries that Bane was able to inflict on Batman. In his “Rogues Gallery” Scott Beatty describes Bane as 2 meters (6′8″) tall and weighing 140 kilograms (350 pounds) with no known “real name” and with a listed occupation of “professional criminal.” Bane was born into a military prison and underwent experiments involving brain injections of a special “venom” that was supposed to create unstoppable super soldiers.
Bane first appeared in January 1993 in Batman: Vengeance of Bane #1. In a series of stories played out in a story arc called Knight-fall, Bane beats Batman and actually “breaks his back” in a titanic battle. The seriousness of this injury in this story is captured by Robin when he says, “But it’s never been this bad. He could be paralyzed. He could die.” Batman is left to recover and has to relearn how to walk while various successors are tried out for him. Eventually, Batman recovers and defeats Bane. However, not before Bane earns infamous distinction as the most physically formidable foe Batman has ever faced. We will return to this story later in this chapter.
I want us to think about two examples of real-life (and extreme) activities that encompass much of what Batman might experience in his fights but which don’t involve the extreme injuries of Bane. We will come back to Bane in a bit, though, so just hold on. These other examples will provide real-life benchmarks for what would be entailed in the Dark Knight’s crime-fighting activities. For just simply getting bashed around, let’s use NFL football in general and running backs in particular. For the grueling experience of fighting, I’ll use “ultimate fighting,” also known as “mixed martial arts.”
What kinds of injuries are typically sustained when your job has the demands of a football playing, mixed martial artist? Let’s look first at mixed martial arts. In several recent surveys of over a 10-year period, about 27% of matches were stopped because of head impact, 16% because of “musculoskeletal stress,” 13% because of neck choke, and 12% due to miscellaneous trauma. So, more than two-thirds of the time significant trauma was experienced. Overall, the injury rate for these competitions is about 29%. This is higher than that seen for boxing, which is around 17%. Even in controlled semirealistic fighting, injuries are a serious concern. For Batman, it would be even more of an issue as there are no rules on the rooftops of Gotham City.
What happens in football? In gridiron football lower-extremity injuries are the most common, although concussion is a major concern, particularly for quarterbacks and running backs. So, let’s begin with concussion and follow that up with skeletal injuries and muscle strains.
What Happens When the Batbrain Gets Bumped?
In football, a running back has to fight through and across the line of scrimmage and try to gain as many yards as possible. While he is doing all that, opposing players are running flat out right at him with the sole intent of slamming into him and forcing him to the ground. Oh, yes, in theory the opposing players are also supposed to be trying to get the ball. Mostly that seems kind of secondary to a thunderous tackle. It is a pretty rough job. As quoted in a 2007 Sports Illustrated article, former New York Giants running back Tiki Barber describes the experience: “Lie down on the floor 30 times and then get up. It’s hard. Now imagine getting knocked down 30 times and getting up. Every day.” If we change “every day” to “every night” we would have a good description of what happens to Batman.
The question that is relevant to us is whether that is really such a horrible thing to happen to somebody—does getting knocked down repeatedly really cause some bad things to occur? The answer is mostly “yes,” and mostly it has to do with what happens when someone is actually hit by someone (or something) else. When this occurs, large forces are experienced, and these result in large accelerations of the body of the person being hit. (Recall that we learned about acceleration and force in Chapter 10.) This is a very big problem if the part of the body getting hit—or subsequently hitting something—is the head.
Despite the many knocks on the head Batman takes regularly, he hardly ever seems to suffer from symptoms of concussion and is rarely even shown as being susceptible to concussion. One of the closest admissions that getting slugged all the time might not be so great can be found in “This One’ll Kill You Batman” (Batman #260, 1975). In this story Batman suffers the effects of both getting hit—again—and drinking some coffee with a sedative in it. He remarks (as Bruce Wayne) to Alfred that despite needing “a computer to count the skull knocks I’ve taken . . . I’ve never experienced symptoms like these!” Later, when revisiting of the story of Man-Bat in “Wings” (Legends of the Dark Knight #5, 1998), Alfred comes right out and says, “You received a severe concussion in t
hat fall with those idiotic birdwings.” Despite the fact that Batman corrects Alfred in using “batwings,” this is still one of the rare times where there is an admission of the possibility of concussion. Putting aside for a minute how unbelievable it is that Batman could take all the falls and the direct blows to the head that he does and yet rarely experience a concussion, let’s continue to look at what concussion really means.
We’ve all heard the term “concussion” so often that the real meaning is probably pretty much lost on most of us. The Merriam-Webster dictionary defines concussion as “a jarring injury of the brain resulting in disturbance of cerebral function.” What does that really mean, though? What is a jarring injury and does something as mild sounding as “disturbance” really have any significance? If we heard on the six o’clock news that a weather “disturbance” could be expected I doubt we’d get up in arms about it. However, a disturbance of cerebral function does sound a bit more ominous. Let’s look at what that could really be.
If we delve somewhat deeper and beyond the rather superficial dictionary definition of concussion, we might find something such as prepared by Kimberly Harmon, which reads that concussion, the “most common form of head injury in athletics,” is “a transient disturbance of neurologic function caused by trauma.” Concussion symptoms include dizziness, headache, and impairment of vision, balance, and the ability to concentrate. Amnesia for events that happened after the traumatic head injury and outright loss of consciousness may occur. It is the latter that made diagnoses and response to concussion so difficult for so long in sports. It seemed for the longest time that, if a player wasn’t knocked unconscious, he didn’t have anything to worry about. Batman is just the opposite and routinely finds himself knocked unconscious and being groggily revived by Robin, Alfred, or someone else but still doesn’t have a concussion!