Editing VO2 max (section)

==Estimation using submaximal exercise testing==
The necessity for a subject to exert maximum effort in order to accurately measure V̇O<sub>2</sub> max can be dangerous in those with compromised respiratory or cardiovascular systems; thus, [[Submaximal performance testing|sub-maximal tests]] for ''estimating'' V̇O<sub>2</sub> max have been developed.

===The heart rate ratio method===
An estimate of V̇O<sub>2</sub> max is based on maximum and resting heart rates. In the Uth ''et al.'' (2004) formulation, it is given by:<ref name="uth">{{cite journal|title=Estimation of VO2max from the ratio between HRmax and HRrest--the Heart Rate Ratio Method|last=Uth|first=Niels|author2=Henrik Sørensen |author3=Kristian Overgaard |author4=Preben K. Pedersen |date=January 2004|journal=Eur J Appl Physiol |volume=91|pages=111–5 |pmid=14624296 |doi=10.1007/s00421-003-0988-y |issue=1|s2cid=23971067|url=https://pure.au.dk/ws/files/14557663/UTH2004.pdf}}</ref>
:<math chem>\ce{\dot VO2}\max \approx \frac{\text{HR}_\max}{\text{HR}_\text{rest}} \times 15.3\text{ mL}/(\text{kg}\cdot\text{minute})</math>

This equation uses the ratio of maximum heart rate (HR<sub>max</sub>) to resting heart rate (HR<sub>rest</sub>) to predict V̇O<sub>2</sub> max. The researchers cautioned that the conversion rule was based on measurements on well-trained men aged 21 to 51 only, and may not be reliable when applied to other sub-groups. They also advised that the formula is most reliable when based on actual measurement of maximum heart rate, rather than an age-related estimate.

The Uth constant factor of 15.3 is given for well-trained men.<ref name="uth"/> Later studies have revised the constant factor for different populations. According to Voutilainen ''et al.'' 2020, the constant factor should be 14 in around 40-year-old normal weight never-smoking men with no cardiovascular diseases, bronchial asthma, or cancer.<ref name="voutilainen">{{cite journal|title=Estimating Maximal Oxygen Uptake from the Ratio of Heart Rate at Maximal Exercise to Heart Rate at Rest in Middle-Aged Men|last=Voutilainen|first=Ari |author2=Mounir Ould Setti |author3=Tomi-Pekka Tuomainen |date=July 2020|journal=World J Mens Health |volume=38|issue=4|pages=666–672 |doi=10.5534/wjmh.200055|pmc=8443998 |issn=2287-4208 |pmid=32777866|url=https://wjmh.org/Synapse/Data/PDFData/2074WJMH/wjmh-38-e39.pdf|doi-access=free}}</ref>
Every 10 years of age reduces the coefficient by one, as well as does the change in body weight from normal weight to obese or the change from never-smoker to smoker. Consequently, V̇O<sub>2</sub> max of 60-year-old obese smoking men should be estimated by multiplying the HR<sub>max</sub> to HR<sub>rest</sub> ratio by 10.

===Cooper test===
[[Kenneth H. Cooper]] conducted a study for the [[United States Air Force]] in the late 1960s. One of the results of this was the [[Cooper test]] in which the distance covered running in 12 minutes is measured.<ref>{{cite journal |last1=Cooper |first1=Kenneth H. |title=A Means of Assessing Maximal Oxygen Intake: Correlation Between Field and Treadmill Testing |journal=JAMA |date=15 January 1968 |volume=203 |issue=3 |pages=203 |doi=10.1001/jama.1968.03140030033008 |url=https://doi.org/10.1001/jama.1968.03140030033008 |language=en |issn=0098-7484|url-access=subscription }}</ref> Based on the measured distance, an estimate of V̇O<sub>2</sub> max [in mL/(kg·min)] can be calculated by inverting the linear regression equation, giving us:

:<math chem>\ce{\dot VO2}\max \approx {d_{12} - 504.9 \over 44.73}</math>

where ''d''<sub>12</sub> is the distance (in metres) covered in 12 minutes.

An alternative equation is:

:<math chem>\ce{\dot VO2}\max \approx {(35.97 * d'_{12}) - 11.29}</math>

where ''d''&prime;<sub>12</sub> is distance (in miles) covered in 12 minutes.

=== Multi-stage fitness test ===
There are several other reliable tests and V̇O<sub>2</sub> max calculators to estimate V̇O<sub>2</sub> max, most notably the [[multi-stage fitness test]] (or ''beep'' test).<ref>[Leger, Luc A., and J_ Lambert. "A maximal multistage 20-m shuttle run test to predict\ dot VO2 max." European journal of applied physiology and occupational physiology 49.1 (1982): 1-12.]</ref>

=== Rockport fitness walking test ===
Estimation of V̇O<sub>2</sub> max from a timed one-mile track walk (as fast as possible) in decimal minutes ({{mvar|t}}, e.g.: 20:35 would be specified as 20.58), sex, age in years, body weight in pounds ({{math|BW}}, lbs), and 60-second heart rate in beats-per-minute ({{math|HR}}, bpm) at the end of the mile.<ref>{{cite journal |vauthors=Kilne G, etal | year = 1987 | title = Estimation of VO2 max from a one mile track walk, sex, age and body weight | journal = Med. Sci. Sports Exerc. | volume = 19 | issue = 3| pages = 253–259 | pmid = 3600239 }}</ref> The constant {{mvar|x}} is 6.3150 for males, 0 for females.

:<math chem>\ce{\dot VO2}\max \approx 132.853 -0.0769\cdot\text{BW} -0.3877\cdot\text{age} -3.2649t -0.1565\cdot\text{HR} +x</math>

[[Correlation coefficient]] {{mvar|r}} for the generalized formula is 0.88.