Wilmore (2008) describes exercise physiology as the study of how the human body structure and function are altered by exposure to acute and chronic bouts of exercise. Clinically, exercise physiology refers to the study of how the body reacts to physical stress. The study also encompasses scientific fitness, involves fitness preservation, and is concerned with the functions of fitness in disease prevention and treatment. It can also be defined as a branch of physiology concerned with how the body adapts physiologically to the acute (short-term) stress of exercise or physical activity and the chronic (long-term) stress of physical training.
Whereas exercise physiology is the study of how body structures and functions are altered when one is exposed to acute and chronic bouts of exercise, sports physiology on the hand, applies the concepts of exercise physiology to enhance performance for instance an athlete’s sport performance (Wilmore, 2004). Therefore, sports physiology is the application of exercise physiology.
Research study conducted by Department of Community health revealed, “an investigation to find out whether a single acute bout of exercise, had a detrimental effect on plasma HIV RNA levels. Twenty-five patients with HIV infection performed one 15-min bout of acute exercise. Absolute neutrophil counts, serum creatine phosphokinase, and 72-h urinary 3-methylhistidine were measured before and after the exercise, along with plasma HIV RNA levels. There were increases in neutrophil counts, serum creatine phosphokinase and urinary 3-methylhistidine in response to exercise, indicating a mild acute-phase response with muscle proteolysis. However, mean HIV RNA, which was elevated at baseline in 22 of the 25 subjects, did not increase during the week after exercise. Small changes in RNA were seen in the three subjects with initially undetectable HIV RNA, but the significance of these changes is unclear. Acute exercise does not have a deleterious effect on HIV replication in adults with high viral loads. Because regular exercise training has not been shown to activate the acute-phase response, the lack of increased viral loads in response to an acute exercise intervention suggests that exercise training is safe in people with HIV infection” (Roubenoff, 1999).
A research study design refers to how subjects are organized and observed. Research study designs are experimental or observational. In experimental studies, groups in research designs participate in new interventions while the researcher observes to find out the changes. Observational studies rely on already existing activities. Wilmore (2008) in their book “Physiology of Sport and Exercise” states that, it is important to be as careful as possible in designing the study and collecting the data (p. 20). Individual differences must be accounted for (Fink, 2009). The researcher obtains adequate data and chooses adequate outcome measures or endpoints.
Fink (2009) states that, “…methodological quality consists of setting standards for high quality studies” (p. 95). You will be required to review only the studies that meet the required standards. A researcher must focus on sound studies to get accurate results. The researcher should know if the study is internally and externally valid. Data sources must be reliable and the analytic methods appropriate to give out meaningful results in both practical and statistical terms. Cross-sectional studies are necessary to begin with before one before a decision is made for better designs. Prospective studies produce more convincing results. Experimental studies provide evidence on how one thing affects another.
Swimming and walking briskly are some of the examples of the physical activities in humans. Swimming is simply movement in a liquid in this case, water. Walking briskly is a form of aerobic exercise that increases heart rate for an extended time (Costill, 1992). Exercise helps to improve one’s lungs and muscle. Energy is required for both swimming and brisk walking. Carbohydrates, fat and proteins are the major sources of fuel in the human activity.
Carbohydrates are the primary fuel used by muscles during competitive swimming (Costill, 1992). Blood glucose and muscle glycogen offer the body energy source. Glucose is the major source of energy during competitive swimming. Consequently if blood glucose declines or muscle glycogen is depleted, the swimmer will feel fatigued and unable to produce force needed to sustain a desired swimming pace (Costill, 1992). Glucose exerts an influence on both protein and fat metabolism, sparing the use of protein as an energy source and controlling the utilization of fat. Grains, fruits vegetables, milk and concentrated sweets are a good source of carbohydrates.
Fats can be used by muscles as an alternate fuel during swimming. Energy production from this source cannot adequately meet the demands required during high competitive swimming. Fat is an essential component of cell walls and nerve fibers, it is a primary source of energy when the body is resting. During swimming it adds buoyancy reducing the energy needed to maintain the body on the surface of the water.
Proteins are nitrogen containing compounds formed by amino acids. They constitute the major structural component of the cell, antibodies, enzymes and many hormones. Proteins are necessary for growth, repair and maintenance of the body tissues. Proteins are potential sources of energy but are spared when fat and carbohydrates are available in ample supply. The increase of capillaries provides more oxygen and energy nutrients during exercise. During sustained lower intensity effort like brisk walking and slow swimming, the brain will call upon mostly type1 muscle fibers. The intensity here is low so epinephrine levels will only be slightly elevated. Working muscle cells will be primarily fueled by fatty acids, with the majority coming from the blood (Wildman, 2002).
Brisk walking requires both carbohydrates and fat. Physical exercises burn fats because calories used in human bodies while they are resting are derived from fats and carbohydrates. On the other hand, proteins are not regarded as primary sources of energy except in times of starvation or prolonged illness (Wildman, 2002). Less fat and more carbohydrates per each calorie of ones body are burnt when the exercise intensity is enhanced from walking briskly to running. The more oxygen you take in the more calories burned. Brisk walking enables maximum fat burning. Protein may contribute some more energy when glycogen is depleted. So the intensity of the exercise determines the fuel your body will use. Carbohydrates are a faster source of energy which can be required during high intensity exercise. In low intensity activities, fats are a good source of energy. The ratio of which fuel is used depends on the type of activity either low intensity or high intensity activity (Costill, 1992).
There is less information available on protein utilization while exercising. This is because oxidation of amino acids contributes less than 5% to the total energy cost during endurance exercise (Kang, 2008). Mild and moderate intensity activities performed over periods of hours can result into increments of energy expenditure with a substantial contribution coming from lipid stores. Therefore the body requires carbohydrates, fats and proteins in different intensity levels of activities that it is performing. Either high intensity, low intensity or while resting. At all these levels the body utilizes alternative energy source.
Reference List
Costill, D. (1992). Swimming. New York. Willey.
Fink, A. (2009). Conducting Research Literature Reviews. New York: SAGE.
Kang, J. (2008). Bioenergetics Primer for Exercise Science. Idaho: Human Kinetics.
Roubenoff, R. (1999). Effects of a Single Bout of Acute Exercise on Plasma Human immunodeficiency virus RNA levels. Journal of Applied Physiology, vol. 86, 4, 1197-1201. Web.
Wildman, R. (2002). The Nutritionists: Food, Nutrition and Optimal Health. Routledge: New York.
Wilmore, J., Costill., & Kenney, L. (2008). Physiology of Sport and Exercise. Idaho: Human Kinetics.