Exercise physiology
[5][6] Hill and German physician Otto Meyerhof shared the 1922 Nobel Prize in Physiology or Medicine for their independent work related to muscle energy metabolism.
Accredited Exercise Physiologists (AEP's) are university-trained professionals who prescribe exercise-based interventions to treat various conditions using dose response prescriptions specific to each individual.
For short duration muscular exertion, energy expenditure can be far greater: an adult human male when jumping up from a squat can mechanically generate 314 W/kg.
[19] Energy needed to perform short lasting, high intensity bursts of activity is derived from anaerobic metabolism within the cytosol of muscle cells, as opposed to aerobic respiration which utilizes oxygen, is sustainable, and occurs in the mitochondria.
The ability of the liver to release glucose into the blood from glycogenolysis is unique, since skeletal muscle, the other major glycogen reservoir, is incapable of doing so.
Unlike skeletal muscle, liver cells contain the enzyme glycogen phosphatase, which removes a phosphate group from glucose-6-P to release free glucose.
For instance, both epinephrine and growth hormone also stimulate adipocyte lipase, which increases non-esterified fatty acid (NEFA) release.
By oxidizing fatty acids, this spares glucose utilization and helps to maintain blood sugar level during exercise.
Likely due to this connection, weight loss from both exercise and diet tends to increase insulin sensitivity in the majority of people.
Although the negative effects of exercise-induced dehydration on exercise performance were clearly demonstrated in the 1940s, athletes continued to believe for years thereafter that fluid intake was not beneficial.
Cycling for 2 hours in the heat (35 °C) with minimal fluid intake causes body mass decline by 3 to 5%, blood volume likewise by 3 to 6%, body temperature to rise constantly, and in comparison with proper fluid intake, higher heart rates, lower stroke volumes and cardiac outputs, reduced skin blood flow, and higher systemic vascular resistance.
For this reason, brain energy consumption is increased during intense physical exercise due to the demands in the motor cognition needed to control the body.
Cerebral autoregulation usually ensures the brain has priority to cardiac output, though this is impaired slightly by exhaustive exercise.
Research suggests that this can be raised, when a person rests in a brain scanner, to about 17%,[40] with a higher percentage of 25% occurring during hypoglycemia.
Some famous examples include: Tim Noakes, based on an earlier idea by the 1922 Nobel Prize in Physiology or Medicine winner Archibald Hill[56] has proposed the existence of a central governor.
In this, the brain continuously adjusts the power output by muscles during exercise in regard to a safe level of exertion.
These neural calculations factor in prior length of strenuous exercise, the planned duration of further exertion, and the present metabolic state of the body.
[58][59][60][61] The idea of the central governor has been questioned since ‘physiological catastrophes’ can and do occur suggesting that if it did exist, athletes (such as Dorando Pietri, Jim Peters and Gabriela Andersen-Schiess) can override it.
In contrast, the processes that create them after strenuous exertion in endurance sports are reversible, with their levels returning to normal within 24-hours (further research, however, is still needed).
[70][71][72] Humans are specifically adapted to engage in prolonged strenuous muscular activity (such as efficient long distance bipedal running).
Humans, unlike other animals that catch prey, remove heat with a specialized thermoregulation based on sweat evaporation.
[75] Another mechanism is increased skin blood flow during exercise that allows for greater convective heat loss that is aided by our upright posture.
This skin based cooling has resulted in humans acquiring an increased number of sweat glands, combined with a lack of body fur that would otherwise stop air circulation and efficient evaporation.
[78] For example, laboratory rats have been bred for high or low performance on a motorized treadmill with electrical stimulation as motivation.
Physical exercise may cause pain both as an immediate effect that may result from stimulation of free nerve endings by low pH, as well as a delayed onset muscle soreness.
[83] Muscle pain can range from a mild soreness to a debilitating injury depending on intensity of exercise, level of training, and other factors.
A program that focuses on the scientific study of the physiological processes involved in physical or motor activity, including sensorimotor interactions, response mechanisms, and the effects of injury, disease, and disability.
Careers available with a degree in Exercise Physiology can include: non-clinical, client-based work; strength and conditioning specialists; cardiopulmonary treatment; and clinical-based research.
[86] In order to gauge the multiple areas of study, students are taught processes in which to follow on a client-based level.
Not only is a full class schedule needed to complete a degree in Exercise Physiology, but a minimum amount of practicum experience is required and internships are recommended.
