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Long-distance running, or endurance running, is a form of continuous running over distances of at least 3 km (1.9 mi). Physiologically, it is largely aerobic in nature and requires stamina as well as mental strength.
Aerobic exercise is physical exercise of low to high intensity that depends primarily on the aerobic energy-generating process. "Aerobic" is defined as "relating to, involving, or requiring oxygen", and refers to the use of oxygen to meet energy demands during exercise via aerobic metabolism adequately. Aerobic exercise is performed by repeating sequences of light-to-moderate intensity activities for extended periods of time. Examples of cardiovascular or aerobic exercise are medium- to long-distance running or jogging, swimming, cycling, stair climbing and walking.
Anaerobic exercise is a type of exercise that breaks down glucose in the body without using oxygen; anaerobic means "without oxygen". In practical terms, this means that anaerobic exercise is more intense, but shorter in duration than aerobic exercise.
Exercise intensity refers to how much energy is expended when exercising. Perceived intensity varies with each person. It has been found that intensity has an effect on what fuel the body uses and what kind of adaptations the body makes after exercise. Intensity is the amount of physical power that the body uses when performing an activity. For example, exercise intensity defines how hard the body has to work to walk a mile in 20 minutes.
Strength training, also known as weight training or resistance training, involves the performance of physical exercises that are designed to improve strength and endurance. It is often associated with the lifting of weights. It can also incorporate a variety of training techniques such as bodyweight exercises, isometrics, and plyometrics.
Excess post-exercise oxygen consumption is a measurably increased rate of oxygen intake following strenuous activity. In historical contexts the term "oxygen debt" was popularized to explain or perhaps attempt to quantify anaerobic energy expenditure, particularly as regards lactic acid/lactate metabolism; in fact, the term "oxygen debt" is still widely used to this day. However, direct and indirect calorimeter experiments have definitively disproven any association of lactate metabolism as causal to an elevated oxygen uptake.
In oncology, the Warburg effect is the observation that most cancer cells release energy predominantly not through the 'usual' citric acid cycle and oxidative phosphorylation in the mitochondria as observed in normal cells, but through a less efficient process of 'aerobic glycolysis' consisting of a high level of glucose uptake and glycolysis followed by lactic acid fermentation taking place in the cytosol, not the mitochondria, even in the presence of abundant oxygen. This observation was first published by Otto Heinrich Warburg, who was awarded the 1931 Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme". The precise mechanism and therapeutic implications of the Warburg effect, however, remain unclear.
Aerobic conditioning is a process whereby the heart and lungs are trained to pump blood more efficiently, allowing more oxygen to be delivered to muscles and organs. The skeletal muscles also become aerobically conditioned, as regular aerobic exercise produces a shift in muscle fibres from more type II into more type I (slow-twitch/oxidative). Type I muscle fibres have far more mitochondria than type II, making type I fibres the producers of adenosine triphosphate (ATP) primarily through oxidative phosphorylation rather than anaerobic glycolysis. Some neuromuscular diseases recommend regular aerobic exercise in order for the skeletal muscles to become aerobically conditioned, providing relief of symptoms or slowing the course of the disease, for example metabolic myopathies and Duchenne muscular dystrophy.
Interval training is a type of training exercise that involves a series of high-intensity workouts interspersed with rest or break periods. The high-intensity periods are typically at or close to anaerobic exercise, while the recovery periods involve activity of lower intensity. Varying the intensity of effort exercises the heart muscle, providing a cardiovascular workout, improving aerobic capacity and permitting the person to exercise for longer and/or at more intense levels.
Lactate inflection point (LIP) is the exercise intensity at which the blood concentration of lactate and/or lactic acid begins to increase rapidly. It is often expressed as 85% of maximum heart rate or 75% of maximum oxygen intake. When exercising at or below the lactate threshold, any lactate produced by the muscles is removed by the body without it building up.
A cycling power meter is a device on a bicycle that measures the power output of the rider. Most cycling power meters use strain gauges to measure torque applied, and when combined with angular velocity, calculate power.
Endurance training is the act of exercising to increase endurance. The term endurance training generally refers to training the aerobic system as opposed to the anaerobic system. The need for endurance in sports is often predicated as the need of cardiovascular and simple muscular endurance, but the issue of endurance is far more complex. Endurance can be divided into two categories including: general endurance and specific endurance. It can be shown that endurance in sport is closely tied to the execution of skill and technique. A well conditioned athlete can be defined as, the athlete who executes his or her technique consistently and effectively with the least effort. Key for measuring endurance are heart rate, power in cycling and pace in running.
Incremental exercise is physical exercise that increases in intensity over time.
Fetal scalp blood testing is a technique used in obstetrics during active labor to confirm whether a fetus is receiving enough oxygen. This is a supplementary procedure used to determine if fetal acidemia has occurred following fetal cardiac distress. While continuous fetal heart rate monitoring is the primary method for assessing fetal wellbeing during labor, a change in fetal heart rate is not indicative of fetal acidemia. Some of the signs and symptoms of oxygen deprivation are pH in the umbilical cord, abnormal fetal heartbeat and abnormal coloration of amniotic fluid. This correlation can only be concluded by sampling fetal scalp blood and measuring acid status. Therefore, fetal scalp blood testing could be used to reduce the number of unnecessary emergency caesarean sections made on the decision of fetal heart rate alone.
The ergonometer test is an anaerobic exercise test, most often performed on a stationary bicycle, that measures peak anaerobic power and anaerobic capacity. The test, which can also be performed on an arm crank ergometer, consists of a set time pedalling at maximum speed against a given resistance. The prototype test based on the Cumming’s test was introduced in 1974, at the Wingate Institute and has undergone modifications as time has progressed. The Wingate test has also been used as a basis to design newer tests in the same vein, and others that use running as the exercise instead of cycling. Sprint interval testing such as is similar to the construction of the Wingate test has been shown to increase both aerobic and anaerobic performance.
The lactate shuttle hypothesis describes the movement of lactate intracellularly and intercellularly. The hypothesis is based on the observation that lactate is formed and utilized continuously in diverse cells under both anaerobic and aerobic conditions. Further, lactate produced at sites with high rates of glycolysis and glycogenolysis can be shuttled to adjacent or remote sites including heart or skeletal muscles where the lactate can be used as a gluconeogenic precursor or substrate for oxidation. The hypothesis was proposed by professor George Brooks of the University of California at Berkeley.
Hypoventilation training is a physical training method in which periods of exercise with reduced breathing frequency are interspersed with periods with normal breathing. The hypoventilation technique consists of short breath holdings and can be performed in different types of exercise: running, cycling, swimming, rowing, skating, etc.
In kinesiology, the ventilatory threshold (VT1) refers to the point during exercise at which ventilation starts to increase at a faster rate than VO2 (V – volume, O2 – oxygen). One's threshold is said to reflect levels of anaerobiosis and lactate accumulation. As the intensity level of the activity being performed increases, breathing becomes faster; more steadily first and then more rapid as the intensity increases. When breathing surpasses normal ventilation rate, one has reached ventilatory threshold. For most people this threshold lies at exercise intensities between 50% and 75% of VO2 max. A major factor affecting one's ventilatory threshold is their maximal ventilation (amount of air entering and exiting lungs). This is dependent on their personal experience with the activity and how physically fit the person is. Comparison studies of more athletic people have shown that your ventilatory threshold occurs at a higher intensity if you are more active or have been training for that exercise; although, in some cases shorter continuous tests can be used because of rapid alterations in ventilation.
Physical exercise has been found to be associated with changes in androgen levels. In cross-sectional analyses, aerobic exercisers have lower basal total and free testosterone compared to the sedentary. Anaerobic exercisers also have lower testosterone compared to the sedentary but a slight increase in basal testosterone with resistance training over time. There is some correlation between testosterone and physical activity in the middle aged and elderly. Acutely, testosterone briefly increases when comparing aerobic, anaerobic and mixed forms of exercise. A study assessed men who were resistance trained, endurance trained, or sedentary in which they either rested, ran or did a resistance session. Androgens increased in response to exercise, particularly resistance, while cortisol only increased with resistance. DHEA increased with resistance exercise and remained elevated during recovery in resistance-trained subjects. After initial post-exercise increase, there was decline in free and total testosterone during resistance recovery, particularly in resistance-trained subjects. Endurance-trained subjects showed less change in hormone levels in response to exercise than resistance-trained subjects. Another study found relative short term effects of aerobic, anaerobic and combined anaerobic-aerobic exercise protocols on hormone levels did not change. The study noted increases in testosterone and cortisol immediately after exercise, which in 2 hours returned to baseline levels.
The physiology of marathons is typically associated with high demands on a marathon runner's cardiovascular system and their locomotor system. The marathon was conceived centuries ago and as of recent has been gaining popularity among many populations around the world. The 42.195 km distance is a physical challenge that entails distinct features of an individual's energy metabolism. Marathon runners finish at different times because of individual physiological characteristics.
References
- ↑ Conconi, Francesco; M. Ferrare; et al. (1982). "Determination of the anaerobic threshold by a non-invasive field test in runners". Journal of Applied Physiology. 52 (4): 869–73. doi:10.1152/jappl.1982.52.4.869. PMID 7085420.
- ↑ Jones, Andrew M.; Jonathan H. Doust (1995). "Lack of reliability in Conconi's heart rate deflection point". International Journal of Sports Medicine. 16 (8): 541–544. doi:10.1055/s-2007-973051. PMID 8776209.
- ↑ Jones, Andrew M.; Jonathan H. Doust (1997). "The Conconi test is not valid for estimation of the lactate turnpoint in runners". Journal of Sports Sciences. 15 (4): 385–394. doi:10.1080/026404197367173. PMID 9293415.
- ↑ Bourgois, Jan; Coorevits, Pascal; Danneels, Lieven; Witvouw, Erik; Cambier, Dirk; Vrijens, Jacques (2004). "Validity of the heart rate deflection point as a predictor of lactate threshold concepts during cycling". Journal of Strength and Conditioning Research. 18 (3): 498–503. doi:10.1519/1533-4287(2004)18<498:VOTHRD>2.0.CO;2. ISSN 1533-4287. PMID 15320666. S2CID 10970208.
- ↑ Sentija, D.; V. Vucetic; C. Markovic (2007). "Validity of the Modified Conconi Running Test". International Journal of Sports Medicine. 28 (12): 1006–1011. doi:10.1055/s-2007-965071. PMID 17614011.
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