Editing Aerobic exercise (section)

== Definition ==
[[File:Exercise zones Fox and Haskell.svg|thumb|300px|[[Fox and Haskell formula]] shows the split between aerobic (light orange) and anaerobic (dark orange) exercise and heart rate.]]
{{Main|Bioenergetic systems}}
{{More citations needed section|date=October 2011|talk=y}}
Aerobic exercise comprises innumerable forms.<ref name="Exercise and Physical Fitness"/> In general, it is performed at a moderate level of intensity over a relatively long period of time. For example, [[running]] a long distance at a moderate pace is an aerobic exercise, but [[Sprint (running)|sprinting]] is not. Playing singles tennis, with near-continuous motion, is generally considered aerobic activity, while activities with brief bursts of energetic movement within longer periods of casual movement may not be aerobic. Some sports are thus inherently "aerobic", while other aerobic exercises, such as [[fartlek]] training or aerobic dance classes, are designed specifically to improve aerobic capacity and fitness. It is most common for aerobic exercises to involve the leg muscles, primarily or exclusively. There are some exceptions. For example, [[Rowing (sport)|rowing]] to distances of 2,000 meters or more is an aerobic sport that exercises several major muscle groups, including those of the legs, abdominals, chest, and arms.

=== Examples===
[[File:US Army 51673 aerobathon.jpg|thumb|300px|A [[step aerobics]] exercise instructor motivates her class to keep up the pace.]]
'''Moderate activities'''<ref>{{Cite web|title=Aerobic Exercise Health: What Is It, Benefits & Examples|url=https://my.clevelandclinic.org/health/articles/7050-aerobic-exercise|access-date=2021-11-19|website=Cleveland Clinic}}</ref>
* [[Swimming]]<ref name=":4" />
* [[Dance|Dancing]]
* [[Hiking]] on flat ground
* [[Cycling|Bicycling]]<ref name=":4"/> at less than {{convert|10|mph|km/h}}
* Moderate [[walking]] (about {{convert|3.5|mph|km/h}})
* [[Alpine skiing|Downhill skiing]]
* [[Doubles (tennis)|Tennis (doubles)]]
* [[Softball]]
* [[Gardening]]
* Light [[Lawn|yard work]]
*[[Jogging]]<ref name=":4" />

'''Vigorous activities'''

* Brisk walking (about {{convert|4.5|mph|km/h}})
* Bicycling at more than {{convert|10|mph|km/h}}
* Hiking uphill
* [[Cross-country skiing]]<ref name=":4" />
* [[Stair climbing]]<ref name=":4" />
* [[Soccer]]
* [[Jogging]]
* [[Jumping rope]]
* [[Tennis]] (singles)
* [[Basketball]]
* Heavy yard work<ref>{{Cite web|title=Give your heart a workout: MedlinePlus Medical Encyclopedia|url=https://medlineplus.gov/ency/patientinstructions/000763.htm|access-date=2021-03-31|website=medlineplus.gov}}</ref><ref name=":1">{{cite journal | vauthors = Mellett LH, Bousquet G | title = Cardiology patient page. Heart-healthy exercise | journal = Circulation | volume = 127 | issue = 17 | pages = e571–e572 | date = April 2013 | pmid = 23630089 | doi = 10.1161/CIRCULATIONAHA.112.000880 | doi-access = free }}</ref>
* Elliptical training<ref name=":4" />
* [[Rowing]]<ref name=":4" />

=== Versus anaerobic exercise ===
Aerobic exercise and fitness can be contrasted with [[anaerobic exercise]], of which [[strength training]] and [[short-distance running]] are the most salient examples. The two types of exercise differ by the duration and intensity of muscular contractions involved, as well as by how energy is generated within the muscle.<ref>{{Cite web |title=Anaerobic: MedlinePlus Medical Encyclopedia |url=https://medlineplus.gov/ency/article/002230.htm |access-date=2022-03-26 |website=medlineplus.gov }}</ref> Common [[kettlebell]] exercises combine aerobic and anaerobic aspects. Allowing 24 hours of recovery between aerobic and strength exercise leads to greater fitness.<ref>{{cite journal | vauthors = Robineau J, Babault N, Piscione J, Lacome M, Bigard AX | title = Specific Training Effects of Concurrent Aerobic and Strength Exercises Depend on Recovery Duration | journal = Journal of Strength and Conditioning Research | volume = 30 | issue = 3 | pages = 672–683 | date = March 2016 | pmid = 25546450 | doi = 10.1519/JSC.0000000000000798 | s2cid = 30607588 }}</ref><ref>{{cite journal | vauthors = Sporer BC, Wenger HA | title = Effects of aerobic exercise on strength performance following various periods of recovery | journal = Journal of Strength and Conditioning Research | volume = 17 | issue = 4 | pages = 638–644 | date = November 2003 | pmid = 14636098 | doi = 10.1519/1533-4287(2003)017<0638:eoaeos>2.0.co;2 | s2cid = 22340684 }}</ref>

New research on the endocrine functions of contracting muscles has shown that both aerobic and anaerobic exercise promote the secretion of [[myokine]]s, with attendant benefits including growth of new tissue, tissue repair, and various anti-inflammatory functions, which in turn reduce the risk of developing various inflammatory diseases.<ref>{{cite journal | vauthors = Patel H, Alkhawam H, Madanieh R, Shah N, Kosmas CE, Vittorio TJ | title = Aerobic ''vs'' anaerobic exercise training effects on the cardiovascular system | journal = World Journal of Cardiology | volume = 9 | issue = 2 | pages = 134–138 | date = February 2017 | pmid = 28289526 | pmc = 5329739 | doi = 10.4330/wjc.v9.i2.134 | doi-access = free }}</ref> Myokine secretion in turn is dependent on the amount of muscle contracted, and the duration and intensity of contraction. As such, both types of exercise produce endocrine benefits.

In almost all conditions, anaerobic exercise is accompanied by aerobic (in the presence of oxygen) exercises because the less efficient anaerobic metabolism must supplement the aerobic system due to energy demands that exceed the aerobic system's capacity. During anaerobic exercise, the body must generate energy through other processes than aerobic metabolism, including [[glycolysis]] paired with [[lactic acid fermentation]], and the [[Creatine|phosphocreatine system]] to generate energy in the form of [[Adenosine triphosphate|ATP]].

=== Fuel usage ===
Depending on the intensity of exercise, the body preferentially utilizes certain fuel forms to meet energy demands. The two main fuel sources for aerobic exercise in the body include [[fat]] (in the form of [[adipose tissue]]) and [[glycogen]]. Amino acids can also be used as a fuel source during aerobic exercise, however in moderate proportions (around 3% of the total energy expenditure during exercise<ref>Clauss, M., & Jensen, J. (2025). Effect of exercise intensity, duration, and volume on protein oxidation during endurance exercise in humans: A systematic review with meta-analysis. Scandinavian Journal of Medicine & Science in Sports, 35(4): e70038. https://doi.org/10.1111/sms.70038</ref>). At lower intensity aerobic exercise, the body preferentially uses fat as its main fuel source for [[cellular respiration]], however as intensity increases the body preferentially uses [[glycogen]] stored in the muscles and liver or other carbohydrates, as it is a quicker source of energy.<ref>{{cite journal | vauthors = Murray B, Rosenbloom C | title = Fundamentals of glycogen metabolism for coaches and athletes | journal = Nutrition Reviews | volume = 76 | issue = 4 | pages = 243–259 | date = April 2018 | pmid = 29444266 | pmc = 6019055 | doi = 10.1093/nutrit/nuy001 }}</ref> Aerobic exercise at low or moderate intensity is not a very efficient way to lose fat in comparison to high intensity aerobic exercise. Lipolysis (hydrolysis of triglyceride into fatty acids),<ref>{{Cite journal |last1=Merrick |first1=David |last2=Seale |first2=Patrick |date=June 2020 |title=Skinny Fat Cells Stimulate Wound Healing |journal=Cell Stem Cell |volume=26 |issue=6 |pages=801–803 |doi=10.1016/j.stem.2020.04.021 |issn=1934-5909|doi-access=free |pmid=32502400 }}</ref> not fat burning (conversion of fatty acid to carbon dioxide), explains the intensity-dependent fat mass reduction. It has been shown that fatty acid is consumed for wound healing, where moderate intensity exercise does not produce significant damage like high intensity exercise. The size of adipose tissue is determined by the magnitude of nutrient competition from muscle and lungs for cell regeneration and energy replenishment after exercise.<ref>{{cite journal | vauthors = Harris MB, Kuo CH | title = Scientific Challenges on Theory of Fat Burning by Exercise | journal = Frontiers in Physiology | volume = 12 | pages = 685166 | date = 2021 | pmid = 34295263 | pmc = 8290478 | doi = 10.3389/fphys.2021.685166 | doi-access = free }}</ref>{{Failed verification|date=October 2023}}