The Anaerobic System provides the body with explosive short term energy without the need for oxygen. Stored in the cells in the chemical adenosine triphosphate(ATP), the energy the anaerobic system delivers powers the working muscle cells when the blood is unable to provide them with oxygen quickly enough. Sprinters are powered by the anaerobic system. It enables them to blast out of the blocks and get to their top speed in about 7 to 10 seconds. After that the energy the anaerobic system provides begins to peter out. Most experts on physiology agree the energy generated by the system tends to last a maximum of about 30 seconds before need to be recharged.
Lactic Acid Buildup
When people continue to draw energy from the anaerobic system for an extended period of time, there begins to be a build up of lactic acid in the muscles. This can lead to cramping and cause muscle fatigue. Ideally, the anaerobic system needs a few minutes of rest after generating energy for the muscles. This gives the body time to overcome its oxygen debt and replenish its oxygen supply. Many athletes employ weight training as well as resistance training to increase their body’s anaerobic power. Being able to draw on a strengthened anaerobic system gives elite athletes a competitive edge.
Sustained Activity Requires Oxygen
To survive and function normally, human and most other organisms require oxygen. Most cellular activities in the human body need oxygen to work well. However, muscle tissue has the unique ability to draw energy from the anaerobic system to provide an explosion of energy for a few seconds without oxygen. This comes in handy with the fight or flight response when humans perceive danger or the momentary excitement generated when the opportunity to get a valuable resource occurs. Some postulate that the anaerobic system may be an evolutionary quirk that has helped humans to survive.
Breaking Down Glucose Molecules
The anaerobic system enables the muscles to partake in vigorous activity for short bursts by braking down glucose molecules and drawing on the energy stored in the adenosine triphosphate in the cell. However, all the ATP in the cell is quickly used up and must be replenished through either aerobic or anaerobic respiration. While the anaerobic system can produce a small amount of ATP, the aerobic system produces a lot more ATP much more efficiently. Still, it is the anaerobic system that provides the energy needed for the initial burst of energy needed for any type of activity.
A Toxic Byproduct
Anaerobic respiration in humans causes the build up of the toxic byproduct lactic acid. It collects in the tissues, creates oxygen debt and causes fatigue and other painful side effects. When oxygen rich blood rushes to the tired muscles to repay the oxygen debt, it breaks down the lactic acid into water and carbon dioxide. The increase in the carbon dioxide in the bloodstream stimulates the heart and makes it pump faster to provide more oxygenated blood to be circulated throughout the body. Should cells’ oxygen level drop once again, anaerobic respiration will start again and produce more ATP.
Athletes participating in non-endurance sports often use intense, physical, anaerobic exercise to build up strength, speed and power. Body builders use anaerobic exercise to build muscle mass. When muscle energy systems receive training using anaerobic exercise, high intensity and short duration activities, it enables them to deliver greater performances in intense, short duration, activities lasting from a few seconds to about 2 minutes. If the athlete is participating in an activity that last over two minutes they will need to drawn on both anaerobic and aerobic metabolic components of their training.
Anaerobic metabolism is one part of the natural whole-body metabolic energy expenditure. The body’s fast twitch muscles which allow it to run fast and jump high depend on its anaerobic metabolic system. Participating in intense physical activities that last over four minutes also require a significant anaerobic energy expenditure component when they’re performed at intensity levels that exceed 90% of the athlete’s maximum heart rate. This includes rowing, cycling, running and other high-intensity interval training activities. In sports where repeated short bursts of energy are required the muscles are able to recover and deliver the next burst because of the anaerobic system.
Two Anaerobic Energy Systems
There are two different anaerobic energy systems. One of them is the Alactic Anaerobic System. It has high-energy phosphates, creatine phosphate and adenosine triphosphate. The second is the Lactic Anaerobic System which features anaerobic glycolysis. Muscle cells store limited quantities of high energy phosphates. Glucose is used exclusively in anaerobic glycolysis as a fuel when there isn’t any oxygen or enough ATP. The rapid glucose breakdown creates lactic acid or more accurately, lactate, its conjugate base, at biological pH levels. The Alactic anaerobic system powers physical activities that take 30 seconds or less. The glycolysis-based lactic anaerobic system and the aerobic system dominate activities that take longer.
Surprising Benefit Of Lactate
Traditionally lactate, the anaerobic glycolysis by-product, was seen as detrimental to muscle function. New research shows only when there are very high lactate levels does it cause a problem. In addition to elevated lactate levels, several other changes that take place in and around the cells in the muscles during intense exercise lead to fatigue. Physical exertion naturally leads to elevated levels of concentrations of muscle and blood lactate. A better understanding of lactate and the role of the anaerobic system has shown they can improve the effectiveness of athletic training.
As the intensity of exercise increases, the muscles begin to need more energy than aerobic metabolism can produce. This is called the metabolic threshold. At that point the anaerobic system begins to release more energy to the muscles. However, the anaerobic systems waste products can lead to fatigue eventually. Elite athletes with a superior training staff know how to leverage this ‘muscle burn’ during training to increase an athlete’s strength, power and endurance and help them to produce superior performance during competition. This gives them that final ‘kick’ at just the right time in the heat of intense athletic activity that allows them to defeat their rivals.
Rapid Improvement In Performance
While non-competitive ‘weekend warriors’ exercising just to feel good, lose weight and enjoy other basic health benefits focus primarily on aerobic exercise, elite athletes in peak condition depend on the effective use of the anaerobic system to give them a competitive edge. The energy provided by the anaerobic system enables athletes to improve the tolerance of their muscles, exercise capacity and their ability to deliver outstanding physical feats very rapidly. For these competitive athletes, regularly performing anaerobic exercise is vital for the consistent improvement in their physical prowess.
Identifying The Difference
It’s easy to tell when during exercise the body is relying a great deal on anaerobic metabolism. The muscles begin to feel fatigued, people start breathing harder and it becomes uncomfortable to continue to exercise. People who are not fit or recently began working out can reach this point very quickly if they even walk up stairs too quickly. As the body begins to depend more on the anaerobic system for energy, the heart rate will increase rapidly and signs of over-exertion will become evident. For those just beginning their training regimen, it’s time to rest and allow their bodies to recover. As they approach peak fitness levels, they will be better able to manage the increased anaerobic contribution to their workout.
Anaerobic Capacity Versus Anaerobic Power
A person’s anaerobic capacity refers to their ability to use the glycolytic system in their body to regenerate the ATP they use during exercise or other types of physical activity. Anaerobic power, on the other hand, is a measure of the ability of the body to use the phosphagen system to regenerate ATP. With the appropriate, concerted, interval training sessions it is possible to increase and improve the ability of these energy systems to enhance both the capacity and the amount of power on which people can draw for their normal daily activities or to participate in intense exercise or athletic competitions.
How Anaerobic Training Improves Anaerobic Capacity
There are a number of ways in which anaerobic training is able to increase a person’s anaerobic capacity. One way it does so is by increasing the lactate tolerance of the athlete. Anaerobic training also helps to increase the dimensions of the fibers that make up the fast twitch muscles. Anaerobic training also leads to an increase in the muscles resting levels of creatine phosphate, glycogen, free creatine and ATP. With a higher anaerobic capacity, an athlete increases the length of time they can perform at high intensity levels. It will also enable them to attain and maintain a higher level of intensity during their daily activities or athletic performances.
Diet And Anaerobic Exercise
Anaerobic exercise helps people to develop stronger muscles, but does not burn fat. In order to enjoy the many benefits of anaerobic exercise it is essential to eat a healthy, well-balanced diet. This will help to provide the nutrients the muscles need to grow and become stronger. The diet recommended for people who do the intense anaerobic exercise should include adequate servings from all the basic food groups. This includes:
- Fruits and vegetables
- Bread, cereal, pasta and rice
- Milk, cheese and yogurt
- Beans, eggs, fish, meat, poultry and nuts
- Oils and sweets
- Water and other nutritious fluids
Safe Anaerobic Exercise Tips
To avoid health problems caused by the strain anaerobic exercise puts the body, it is important to visit your doctor to get a thorough checkup and a clean bill of health before beginning an intense anaerobic exercise program. Plus you should immediately stop exercising if you experience any of the following symptoms:
- Severe Fatigue
This can help to prevent serious injury caused by putting too much strain on your body and your anaerobic system. Before returning to the exercise program, you should check with your doctor to ensure it is medically safe.
There is a physiological reason rest periods between intervals of anaerobic workouts are typically longer than those during aerobic workouts. The primary reason for the longer anaerobic intervals is because the body needs more time to reduce the level of lactate and other metabolic wastes that builds up in the muscle tissue and the bloodstream when a great deal of energy is being drawn from the anaerobic system. The body’s anaerobic energy system need time to recharge before it can effectively provide the energy required by intense workouts. Inadequate rest negatively impacts anaerobic power, endurance and muscle strength and overall physical performance.
Sleep And Anaerobic Performance
Getting an adequate amount of sleep is also important to enjoy optimal benefits from anaerobic exercise. The results of several studies show blood lactate concentrations are aﬀected when athletes regularly do intense training that draws on the anaerobic system for energy. Research show that when athletes involved in intense training do not get adequate sleep for two to three days, they are not able to get maximal utilisation of their anaerobic glycogenolytic potential. As a result, there is a decrease in their anaerobic performance. And the issue is caused by more than just blood lactate accumulation. Sleepiness significantly impairs anaerobic performance. Researchers have postulated it may have to do with the disruption of the circadian rhythm.
Examples Of Anaerobic Exercise
Most people are familiar with common aerobic exercises like walking, jogging and swimming. However, not many people are aware of some of the exercises that force humans to draw on the anaerobic system for energy. The activities in this group tend to be short in duration, but very high in intensity. Anaerobic exercise draws on the energy in the muscles. Some of the exercises and activities in this group include:
- Weight training workouts consisting of bench presses, heavy squats and deadlifts
- High-Intensity Interval Training
- Callisthenics like jump squats, box jumps, or other plyometrics
Benefits Of Anaerobic Exercise
Regularly drawing on the energy in the body’s muscles and anaerobic system to power exercise and intense workouts offers many benefits that lead to good health. Some of the ways in which anaerobic exercise benefits the body include:
- Builds And Strengthens The Muscles
- Strengthens The Bones
- Reverses Effects Of Bone Loss
- Reduces The Risk Of Breaking Bones And Developing Osteoporosis
- Burns Fat
- Maintains Lean Muscle Mass
- Tones The Muscles
- Improves Cardiovascular Health
- Helps Improve People’s Moods
- Aids With The Management Of Anxiety, Depression And Other Mental Health Conditions
Made of metabolically active tissue, muscle helps people to burn calories even while they are resting. Doing anaerobic exercises helps to keep the muscles properly toned, healthy and strong. That’s important because after about age 27 people lose about 1% a year of muscle mass. Doing anaerobic exercises can enhance people’s quality of life.
The Anaerobic Glycolytic System’s Four Steps
Producing energy from the anaerobic glycolytic system requires four key steps. They require much longer to complete than the more complex ATP-PC system’s steps. The anaerobic glycolytic system’s steps are:
- Stored glycogen gets converted to glucose which a series of enzymes break down.
- Four ATP are created. Two are used to provide the energy for glycolysis. The other two ATP are used for muscular contraction.
- Breaking down glucose to synthesise ATP creates pyruvate and hydrogen ions. The more hydrogen ions that are created, the more acidic the muscles become.
- The lack of oxygen in the anaerobic system means breaking down the pyruvate and synthesising more ATP is not possible. As a result, the pyruvate and some hydrogen ions becomes bound together and converted into lactate. The lactate temporarily acts as a buffering system which reduces acidosis. No more ATP is synthesised.
The Anaerobic Energy System’s Clinical Importance
The anaerobic energy system helps to provide energy for a wide range of physical activities. The system is very important for physical fitness and human performance. During high intensity training, the anaerobic system goes through anatomic, neural and biochemical adaptations. The physical activity must be performed to near-exhaustion and be of high intensity for it to be considered anaerobic training. Recent research has shown that the anaerobic system of anyone can be trained. This can be particularly helpful to elderly people. They respond well to anaerobic training. It can increase their safety from falls, their independence and their quality of life.
Anaerobic Energy Expenditure
A natural and crucial part of the body’s metabolic system, the anaerobic energy expenditure or anaerobic metabolism is an essential part of the metabolic energy expenditure of the whole body. It strengthens and powers the fast twitch muscle fibers, increases their ability to perform intense anaerobic activities and makes them more effective. While it is difficult to accurately quantify anaerobic energy expenditure, this important system is essential for many everyday activities. The energy released by the anaerobic system benefits both elite athletes and the average person.
Getting More From The Anaerobic System
Being able to get the most output possible from the energy reserves stored in the anaerobic system through glycolytic metabolism requires increasing one’s tolerance to lactic acid. Proper, prolonged training results in increased access to anaerobic capacity as well as anaerobic power through the energy released. Extensive use of intense interval training helps the muscles to adapt to meeting an increasing demand for quick explosive energy. The short-term anaerobic system has a natural interval ratio of 1:2. The length of time involved in putting out energy requires a recovery period that’s twice as long. However, with proper training the output period can be extended from 5 to 10 seconds to as much as a minute.
An Anaerobic System Experiment
One simple way to see how quickly the anaerobic system’s ATP stores are depleted is to do an experiment with your hand. Open your hand and spread your fingers. Then quickly tighten it into a fist. Repeat this every two or three seconds for 30 seconds. You’ll notice it’s easy and effortless to do it for the first 10 seconds and the fist you make is strong. Between 10 and 20 seconds, it becomes increasingly difficult. That’s because the ATP in the muscles is being used up and lactic acid is beginning to build up in the forearm muscles that power the contractions.
Reduction in Speed And Intensity
Between 20 and 30 seconds after beginning the exercise, the tempo of the hand movements begin to slow and contracting the muscles becomes painful. By the 30 second mark, the rate of fist making slows dramatically and the fist isn’t as tight as it was in the beginning. The muscles in the forearm begin to experience a burning sensation and fine motor control of the hand is significantly diminished. That’s because the ATP in the muscles have been used up and the anaerobic system needs time to produce some more. The same thing happens to the legs during an all-out sprint.
Practice Increases Power And Capacity
Were you to continue doing this exercise regularly, it will become easier to meet and exceed the 30 second threshold with less pain. The anaerobic system will begin to delay the onset of the maximum amount of lactic acid the muscles can accommodate. The anaerobic system will become more efficient in pushing back the lactate threshold close to the necessary maximal heart rate for the exercise. Soon the individual will be able to continue the hand exercise for twice the length of time before becoming tired.
Heart Rate And The Lactate Threshold
One way to identify when the anaerobic system has expended most of its ATP is to pay attention to the heart rate. When intense exercise makes the heart rate rise until it’s impossible to speak in full sentences, the muscles have reached their lactate threshold. This triggers anaerobic metabolism. Training for long periods with the heart rate continually above the lactate threshold improves the fitness of an athlete and enables them to do intense exercise with less effort.
If you have any questions on the above or would like some advice on how we could help you with your fitness goal, don’t hesitate, visit our gym and try one of our personal training sessions.
- The Aerobic Energy System
- Cardiovascular Health and Exercise
- Metabolic Training: What It Is And How To Do It
- Cardiac Output: Stroke Volume and Heart Rate
- Fitness Training & Nutrition – A Match Made in the Gym