Cellular Metabolic Collapse
It has taken me half a century to come to an absolutely trivial realization; tennis is a 'sport.' It is not an 'active pastime', like billiards, ping pong, golf or curling, but is an athletic sport like hockey or soccer. I suppose I have always been dimly aware of that fact. I realized that players who could naturally run faster or longer and strike harder might be able to leverage those abilities to conquer and humiliate weekend athletes like myself. But I always held out some hope that superior technique could overcome an opponent's natural athletic ability. Indeed, as my knowledge improved, I found I could occasionally dominate less experienced but fitter 'jocks.' Bet there were too many times when a well-conditioned beginner would clean my clock, notwithstanding my superior stroking ability. My response to these disappointments was to redouble my efforts, culminating in this project. Indeed, my performance has improved remarkably, yet there was still something in my way. Some invisible demon that seemed to have the power to transform a good day on the court into an unqualified disaster. That demon, in whose unseen jaws I have suffered my entire life, has a name; Cellular Metabolic Collapse.
Cellular Metabolic Collapse(CMP) in sports is the pathologic process that renders muscle cells incapable of responding appropriately to neural excitation. You can feel it whenever you strength train with heavy weights. At the end of each set your muscles become completely unable to comply with your demands. The effect lasts several minutes while they 'recharge'. They don't hurt, but they won't respond. CMP is altogether different from running out of breath or overuse muscle soreness. CMP is a silent performance killer. It prevents you from doing the thousand tiny muscle contractions necessary to execute am effective stroke. CMP disconnects the brain from the body; rendering training, knowledge, and experience moot.
The triathlon sports are all about 'juice.' Got juice - you win. Run out of juice - you loose. Never had juice - you picked the wrong sport. You can still run, bike, or swim juiceless, you just don't win. Playing decent tennis also requires juice. Unlike the triathletes, however, when you run out of juice in tennis, you don't fall behind, you fall apart. All of a sudden, the seemingly trivial becomes the apparently impossible. Lobs become bloopers, serves become poopers, groundstrokes fly, and volleys dribble, and your timing goes all to hell. Feet don't move and knees don't bend. Shanks become your speciality. Mind you, all of these can be symptoms of ego collapse, but in that case, there is always something you can do to regain your composure. When you are juiced out, you are done, finished, kaput!
So, duh! I know you know this. I apologize if you feel patronized. For fifty years, I have chased this elusive gremlin. I even wrote my senior thesis on blood sugar and performance in the vain hope that a well-timed candy-bar might solve all of my problems. I have always conceded that metabolic issues such as hydration, overuse, oxygenation, flexibility, endurance, diet, and sleep effect tennis performance. But what I never suspected was the actual depth and breadth of the problem. I understood the poor fitness might prevent one from getting to the ball, but I never suspected that failure of fitness could cause one to mangle, mishit, and muff the balls that one could reach. CMP causes unconscionable, unpredictable, unavoidable errors.
Avoidence of Metabolic Collapse can be as dangerous as the collapse itself. Awareness of our own imperfect state of fitness compels us to modify and degrade our technique. To prevent quad fatigue we bend our knees sparingly or not at all, thereby disrupting balance and the generation of power and control. Weakness in the shoulders and upper back compels us to bring our arms down too early in the overhead, resulting in mishits, errors and ceding the high ground to our opponents. Similarly too early dropping of our tossing arm early in the serve, bending at the waist on low balls, and swinging at the ball instead of snapping the arm and wrist all rob us of the control, spin and power that we desperately need to defeat fitter foes. If you have ever walked out onto the court feeling stiff and useless, warmed up and started playing well, only to end up tired and useless in the end; then you know the whole, sad story of metabolic collapse from its avoidance to its direct effects.
Basic Muscle Metabolism
Muscles contract. That is all they do. The fibers that comprise a muscle don't all contract at once or together. Instead they are recruited, one after another, as needed. The signals that activate a given muscle group come from one branch of one nerve. There are only two states of the nerve; 'on' and 'off,' so how hard a muscle contracts depends on the frequency, not the size, of the nerve signals. Each 'on' signal creates a 'twitch' of the muscle, which adds to create a mechanical contraction.
To contract, the muscles need a source of energy. That source is the blood. Blood provides fuel in the form of glucose, fat and protein. The blood also provides oxygen. The muscle converts whatever fuel it gets to ATP (adenosine triphosphate), which is the ultimate source of energy for the muscle. The muscle can make ATP from any of the three fuels, and it can make it with or without oxygen. 'Burning' of glucose or fat using oxygen (aerobically) produces thirty-two ATP molecules per molecule of fuel. If the muscle has no oxygen available, it can still create ATP directly from fat or glucose, but it can only produce one or two molecules of ATP per molecule of fuel.