An athlete requires energy to fuel all physical actions and movements. This energy is supplied from the macronutrients and micronutrients consumed, and from the oxygen acquired through respiration. In their raw form, the food that provides the macronutrients and micronutrients, and the air that athletes breathe to acquire oxygen, cannot be used in their original state. These raw, unchanged fuel sources are called potential energy. There must be a change that occurs to convert the potential energy, into energy that can be used by the body (McArdle, Katch, & Katch, 2016).
The converted energy, which can be used by the body to fuel physical movement, is called kinetic energy. This process is collectively known as energy transfer. Through a variety of chemical actions and reactions, the body metabolizes the potential energy into kinetic energy, through two primary metabolic energy pathways. These two metabolic energy pathways are the aerobic system, which uses oxygen, and the anaerobic system, which does not use oxygen. This process of energy changing forms is described in the first law of thermodynamics. (McArdle et al., 2016).
The first law of thermodynamics refers to energy changing forms. Energy exists and does not disappear. It simply changes form, so that it can be utilized by different biological functions. In the case of human movement, energy transforms from chemical energy, to mechanical energy, ending with heat energy. This is also known as the conservation of energy. These complex chemical changes, concerning the energy’s form in the body, are known as biosynthesis (Kim & Roberts, 2015).
The body has a process which it uses to release energy and to store energy. The exergonic process releases energy to its surroundings, while the endergonic process stores energy. The energy that is released is known as free energy, and is available to be used in biological functions. These two processes often work together in a very complicated chemical state, to regulate and optimize the availability and use of free energy. Energy itself does not increase or decrease. However, the forms of energy that are available do change, as a result of many different chemical reactions (Kim & Roberts, 2015).
Unfortunately, for the athlete, these changes almost always lead to less kinetic energy available for physical activity. This concept is known as entropy, and it ties directly into the second law of thermodynamics. The second law of thermodynamics refers to the eventual degradation of potential energy, into kinetic or heat energy. This degradation decreases the capacity to perform physical activity (Kim & Roberts, 2015).
Fortunately, when one form of energy decreases, other forms increase. This cycle is continual in nature. The energy doesn’t disappear; it continues to change its form. At any given time, an athlete’s body is performing three types of biological work. These three types of work include mechanical, chemical, and transport. These types of work tie into energy transfer and the metabolic energy pathways. During physical activity and exercise, duration and intensity determine how and where, energy is being transferred and utilized. The aerobic and anaerobic energy pathways have specific functions, in relation to exercise (Chamari & Padulo, 2015).
The anaerobic energy pathway is utilized during short duration, high intensity events such as sprinting, powerlifting, and Olympic weightlifting. The anaerobic system actually has two main subsystems or pathways. The first is the adenosine triphosphate (ATP) and phosphocreatine (CrP) pathway or ATP-CP. This pathway provides the energy for approximately ten seconds. After ten seconds, the second pathway activates. This second pathway is known as the glycolytic pathway. This pathway provides energy for approximately ninety seconds. This is the approximate time window where the anaerobic pathway is thought to end (Chamari & Padulo, 2015).
After ninety seconds, the aerobic or oxidative phosphorylation pathway takes over. This pathway continues providing energy for long duration activities such as distance and endurance events. Within the first two minutes of exercise or physical exertion, the athlete has activated three different energy pathways, belonging to the anaerobic and aerobic systems. Also the three biological forms of work are all functioning to assist with the demands on the body. There are ongoing debates amongst researchers, concerning the exact timings and roles of the energy pathways (Chamari & Padulo, 2015).
Proper nutrition for an athlete is absolutely critical, in order to meet the high energy demands of athletic training. The correct caloric intake, combined with a proper macronutrient ratio is essential for an athlete to meet their needs and goals. The body uses carbohydrates for the bulk of its energy demands. Glucose and glycogen play crucial roles in energy transfer during anaerobic and aerobic metabolism (Liesa & Shirihai, 2013).
Fats come into play during longer duration aerobic events. When muscle and liver glycogen levels, and corresponding glucose levels decrease, more fats are used to sustain energy transfer. Fats transfer energy slower, and can only generate about half as much energy production as carbohydrates, in the same amount of time. When the activity reaches a long duration such as the end of a triathlon or marathon, the remaining macronutrient is called up. The last in line for energy transfer are proteins (Liesa & Shirihai, 2013).
When energy demands are very high, glycogen levels are very low, and fats are too slow during the transfer process, proteins are called upon to help out the team. The athlete does not want to be in this situation, where proteins are being called upon to sacrifice themselves, for energy production. Proteins are broken down into their amino acids through deamination, and other methods that make them suitable for energy transfer. This can cause a loss of lean body mass, and cause decreases in performance, with rising fatigue levels (Longland, Oikawa, Mitchell, Devries, & Phillips, 2016).
Overtraining is a viable threat for hard working athletes. But it can be avoided with proper rest, nutrition, and training. It is very important for an athlete to recover properly after each period of training. Athletes must replenish and maintain their hydration levels, electrolyte levels, and muscle and liver glycogen levels. Consuming the right amount of calories, with the correct ratio of carbohydrates, fats and proteins, is an important part of preventing overtraining. Poor nutrition and dehydration, combined with intense training, poor rest, and high stress levels can propel an otherwise healthy athlete, into the overtraining mode. By eating properly, athletes can maintain an anabolic state and reduce the catabolic effects of intensive training. Coaches need to ensure that their athletes are doing the right things, so that overtraining does not occur (Cadegiani & Kater, 2017).
References:
Cadegiani, F., & Kater, C. (2017). Hormonal aspects of overtraining syndrome. BMC Sports Science, Medicine and Rehabilitation. Retrieved from https://bmcsportsscimedrehabil.biomedcentral.com/articles/10.1186/s13102-017-0079-8
The converted energy, which can be used by the body to fuel physical movement, is called kinetic energy. This process is collectively known as energy transfer. Through a variety of chemical actions and reactions, the body metabolizes the potential energy into kinetic energy, through two primary metabolic energy pathways. These two metabolic energy pathways are the aerobic system, which uses oxygen, and the anaerobic system, which does not use oxygen. This process of energy changing forms is described in the first law of thermodynamics. (McArdle et al., 2016).
The first law of thermodynamics refers to energy changing forms. Energy exists and does not disappear. It simply changes form, so that it can be utilized by different biological functions. In the case of human movement, energy transforms from chemical energy, to mechanical energy, ending with heat energy. This is also known as the conservation of energy. These complex chemical changes, concerning the energy’s form in the body, are known as biosynthesis (Kim & Roberts, 2015).
The body has a process which it uses to release energy and to store energy. The exergonic process releases energy to its surroundings, while the endergonic process stores energy. The energy that is released is known as free energy, and is available to be used in biological functions. These two processes often work together in a very complicated chemical state, to regulate and optimize the availability and use of free energy. Energy itself does not increase or decrease. However, the forms of energy that are available do change, as a result of many different chemical reactions (Kim & Roberts, 2015).
Unfortunately, for the athlete, these changes almost always lead to less kinetic energy available for physical activity. This concept is known as entropy, and it ties directly into the second law of thermodynamics. The second law of thermodynamics refers to the eventual degradation of potential energy, into kinetic or heat energy. This degradation decreases the capacity to perform physical activity (Kim & Roberts, 2015).
Fortunately, when one form of energy decreases, other forms increase. This cycle is continual in nature. The energy doesn’t disappear; it continues to change its form. At any given time, an athlete’s body is performing three types of biological work. These three types of work include mechanical, chemical, and transport. These types of work tie into energy transfer and the metabolic energy pathways. During physical activity and exercise, duration and intensity determine how and where, energy is being transferred and utilized. The aerobic and anaerobic energy pathways have specific functions, in relation to exercise (Chamari & Padulo, 2015).
The anaerobic energy pathway is utilized during short duration, high intensity events such as sprinting, powerlifting, and Olympic weightlifting. The anaerobic system actually has two main subsystems or pathways. The first is the adenosine triphosphate (ATP) and phosphocreatine (CrP) pathway or ATP-CP. This pathway provides the energy for approximately ten seconds. After ten seconds, the second pathway activates. This second pathway is known as the glycolytic pathway. This pathway provides energy for approximately ninety seconds. This is the approximate time window where the anaerobic pathway is thought to end (Chamari & Padulo, 2015).
After ninety seconds, the aerobic or oxidative phosphorylation pathway takes over. This pathway continues providing energy for long duration activities such as distance and endurance events. Within the first two minutes of exercise or physical exertion, the athlete has activated three different energy pathways, belonging to the anaerobic and aerobic systems. Also the three biological forms of work are all functioning to assist with the demands on the body. There are ongoing debates amongst researchers, concerning the exact timings and roles of the energy pathways (Chamari & Padulo, 2015).
Proper nutrition for an athlete is absolutely critical, in order to meet the high energy demands of athletic training. The correct caloric intake, combined with a proper macronutrient ratio is essential for an athlete to meet their needs and goals. The body uses carbohydrates for the bulk of its energy demands. Glucose and glycogen play crucial roles in energy transfer during anaerobic and aerobic metabolism (Liesa & Shirihai, 2013).
Fats come into play during longer duration aerobic events. When muscle and liver glycogen levels, and corresponding glucose levels decrease, more fats are used to sustain energy transfer. Fats transfer energy slower, and can only generate about half as much energy production as carbohydrates, in the same amount of time. When the activity reaches a long duration such as the end of a triathlon or marathon, the remaining macronutrient is called up. The last in line for energy transfer are proteins (Liesa & Shirihai, 2013).
When energy demands are very high, glycogen levels are very low, and fats are too slow during the transfer process, proteins are called upon to help out the team. The athlete does not want to be in this situation, where proteins are being called upon to sacrifice themselves, for energy production. Proteins are broken down into their amino acids through deamination, and other methods that make them suitable for energy transfer. This can cause a loss of lean body mass, and cause decreases in performance, with rising fatigue levels (Longland, Oikawa, Mitchell, Devries, & Phillips, 2016).
Overtraining is a viable threat for hard working athletes. But it can be avoided with proper rest, nutrition, and training. It is very important for an athlete to recover properly after each period of training. Athletes must replenish and maintain their hydration levels, electrolyte levels, and muscle and liver glycogen levels. Consuming the right amount of calories, with the correct ratio of carbohydrates, fats and proteins, is an important part of preventing overtraining. Poor nutrition and dehydration, combined with intense training, poor rest, and high stress levels can propel an otherwise healthy athlete, into the overtraining mode. By eating properly, athletes can maintain an anabolic state and reduce the catabolic effects of intensive training. Coaches need to ensure that their athletes are doing the right things, so that overtraining does not occur (Cadegiani & Kater, 2017).
References:
Cadegiani, F., & Kater, C. (2017). Hormonal aspects of overtraining syndrome. BMC Sports Science, Medicine and Rehabilitation. Retrieved from https://bmcsportsscimedrehabil.biomedcentral.com/articles/10.1186/s13102-017-0079-8
Chamari, K., & Padulo, J. (2015). ‘Aerobic’ and ‘anaerobic’ terms used in exercise physiology. Sports Medicine Open. Retrieved from https://link.springer.com/article/10.1186/s40798-015-0012-1
Kim, J., & Roberts, D. (2015). A joint-space numerical model of metabolic energy expenditure for human multibody dynamic system. International Journal for Numerical Methods in Biomedical Engineering. Retrieved from http://onlinelibrary.wiley.com/doi/10.1002/cnm.2721/full
Liesa, M., & Shirihai, O. (2013). Mitochondrial Dynamics in the Regulation of Nutrient Utilization and Energy Expenditure. Cell Metabolism. Retrieved from http://www.sciencedirect.com/science/article/pii/S1550413113001046
Longland, T., Oikawa, S., Mitchell, C., Devries, M., & Phillips, S. (2016). Higher compared with lower dietary protein during an energy deficit, combined with intense exercise promotes greater lean mass gain and fat mass loss: a randomized trial. American Journal of Clinical Nutrition. Retrieved from http://ajcn.nutrition.org/content/103/3/738.short
McArdle, W.D., Katch, F.I., & Katch, V.L. (2016). Essentials of exercise physiology (5th ed.). Philadelphia: Wolters Kluwer.
Eric Dempsey
Eric Dempsey
MS, NASM Fitness Nutrition Specialist
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