Role of aerobic and anaerobic metabolism in exercise
Exercise is any bodily activity that enhances or maintains physical fitness and overall health and wellness. It is performed for various reasons including strengthening muscles and the cardiovascular system, honing athletic skills, weight loss or maintenance, as well as for the purpose of enjoyment. Frequent and regular physical exercise boosts the immune system, and helps prevent the "diseases of affluence" such as heart disease, cardiovascular disease, Type 2 diabetes and obesity. It also improves mental health, helps prevent depression.
What is exercise?
It is the set of life-sustaining chemical transformations within the cells of living organisms. These enzyme-catalyzed reactions allow organisms to grow and reproduce, maintain their structures, and respond to their environments.
Metabolism is usually divided into two categories. Catabolism, that breaks down organic matter and harvests energy by way of cellular respiration, and anabolism that uses energy to construct components of cells such as proteins and nucleic acids.
METABOLISM
There are two types of metabolism during exercise
Aerobic metabolism
Anaerobic metabolism
Aerobic exercise as the name implies is designed to allow the muscles to continue to perform aerobically i.e. to continuously produce ATP by electron transfer and oxidative phosphorylation. Aerobic exercise depends largely on the concentration of the slow twitch fibers of the skeletal muscles. Although these fibers generate less force, they can continue to function for long period of time due to the continuing production of ATP without production of lactic acid.
Aerobic exercise is initially fueled by the glucose molecules stored as glycogen in the muscle themselves, but after few minutes the muscles depends more on free fatty acids released into blood from adipose tissue.
AEROBIC EXERCISE
Aerobic exercise (also known as cardio) is physical exercise of relatively low intensity that depends primarily on the aerobic energy-generating process.
literally means "relating to, involving, or requiring free oxygen", and refers to the use of oxygen to adequately meet energy demands during exercise via aerobic metabolism. Generally, light-to-moderate intensity activities that are sufficiently supported by aerobic metabolism can be performed for extended periods of time. The intensity should be between 60 and 85% of maximum heart rate.
When practiced in this way, examples of cardiovascular/aerobic exercise are medium to long distance running/jogging, swimming, cycling, and walking rowing, etc.
Aerobic capacity describes the functional capacity of the cardio respiratory system, (the heart, lungs and blood vessels). Aerobic capacity is defined as the maximum amount of oxygen the body can use during a specified period, usually during intense exercise. It is a function both of cardio respiratory performance and the maximum ability to remove and utilize oxygen from circulating blood. To measure maximal aerobic capacity, an exercise physiologist or physician will perform aVO2 max test, in which a subject will undergo progressively more strenuous exercise on a treadmill, from an easy walk through to exhaustion. The individual is typically connected to a respirometer to measure oxygen consumption, and the speed is increased incrementally over a fixed duration of time.
Aerobic capacity
While at rest, we rely on aerobic metabolism to fuel almost all our body's needs for energy. As we start to exercise, such as progressing from sitting to a slow walk, the increased energy needs of muscle contraction require that we increase our breathing and oxygen intake. So long as we increase our exercise intensity slowly, we can maintain our muscles' dependence on aerobic metabolism, and we don't experience symptoms of fatigue.
Increased storage of energy molecules such as fats and carbohydrates within the muscles, allowing for increased endurance.
Reduces risk of osteoporosis, improves strength of heart muscles called as aerobic conditioning , reduces B.P.
Neovascularization of the muscle sarcomeres to increase blood flow through the muscles.
Role of aerobic exercise:
Increasing speed at which aerobic metabolism is activated within muscles, allowing a greater portion of energy for intense exercise to be generated aerobically.
Improving the ability of muscles to use fats during exercise, preserving intramuscular glycogen.
Enhancing the speed at which muscles recover from high intensity exercise.
Increasing the total number of red blood cells in the body, facilitating transport of oxygen
Reducing the risk for diabetes.
Improved mental health, including reducing stress and lowering the incidence of depression, as well as increased cognitive capacity.
The aerobic system acts like a vacuum cleaner, sucking up all the bad stuff that is produced by the anaerobic system. The stronger the vacuum cleaner the more anaerobic work can be done.
Cont….
Overuse injuries because of repetitive, high-impact exercise such as distance running.
Is not an effective approach to building lean muscle.
Only effective for fat loss when used consistently
Downfall of aerobic exercise:
Anaerobic exercise is an exercise intense enough to trigger lactic acid formation. It is used by athletes in non-endurance sports to promote strength, speed and power and by body builders to build muscle mass. Muscle energy systems trained using anaerobic exercise develop differently compared to aerobic exercise, leading to greater performance in short duration, high intensity activities, which last from mere seconds to up to about 2 minutes. Any activity lasting longer than about two minutes has a large aerobic metabolic component.
Anaerobic exercise
Anaerobic metabolism, or anaerobic energy expenditure, is a natural part of whole-body metabolic energy expenditure. Fast twitch muscle(as compared to slow twitch muscle) operates using anaerobic metabolic systems, such that any recruitment of fast twitch muscle fibers leads to increased anaerobic energy expenditure. Intense exercise lasting upwards of about four minutes (e.g., a mile race) may still have a considerable anaerobic energy expenditure component. Anaerobic energy expenditure is difficult to accurately quantify, although several reasonable methods to estimate the anaerobic component to exercise are available.
Anaerobic metabolism
There are two types of anaerobic energy systems: 1) the high energy phosphates, ATP adenosine triphosphate and CP creatine phosphate; and 2) anaerobic glycolysis. The high energy phosphates are stored in very limited quantities within muscle cells. Anaerobic glycolysis exclusively uses glucose (and glycogen) as a fuel in the absence of oxygen or more specifically, when ATP is needed at rates that exceed those provided by aerobic metabolism; the consequence of rapid glucose breakdown is the formation of lactic acid (more appropriately, lactate at biological pH levels). Physical activities that last up to about thirty seconds rely primarily on the former, ATP-CP phosphagen system. Beyond this time both aerobic and anaerobic glycolytic metabolic systems begin to predominate.
Cont…
anaerobic capacity - like aerobic capacity it is the ability to generate energy but through the glycolytic system or the breakdown of glucose. We define it as the maximal or organic potential to produce pyruvate or lactate which is the output of the anaerobic glycolytic system. It is where lactate originates in the body.
Anaerobic capacity
Anaerobic exercise is also called strength or Resistance training and can firm, strengthen, and tone your muscles, as well as improve bone strength, Balance, and Coordination. examples of strength moves are pushups, lunges, and bicep curls using dumbbells. Anaerobic exercise also include weight training, functional training, eccentric training, Interval training, sprinting and high-intensity interval training increase short-term muscle strength.
Flexibility exercises stretch and lengthen your muscles. stretching help to improve joint joint flexibility and keep muscles limber. The goal is to improve the range of motion which can reduce the chance of injury.
Role of anaerobic exercise
Fatigue causes the person to experience added discomfort and weakening muscles. Eventually one will need to slow down and lower his exercise intensity. Slowing down allows the muscles to once again rely solely on aerobic metabolism and support the removal or chemical conversion of waste molecules.
Working too hard, not using oxygen efficiently, quit sooner, would not burn as much calories as in aerobic exercise.
Downfall of anaerobic exercise:
1. Biochemistry an introduction by – Turby McKee and James R. McKee.
2. Cell biology y – Karp3. Wikipedia
Refrence :
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