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Molecular adaptations to endurance exercise and skeletal muscle fibre plasticity
Published in Adam P. Sharples, James P. Morton, Henning Wackerhage, Molecular Exercise Physiology, 2022
Endurance performance depends on many limiting factors. One important factor that will not be discussed in this chapter but is central to endurance performance is neurocognitive drive, or the psychological determinants of endurance. Please see this review article (1) for more information on this topic. The primary musculoskeletal factors that limit endurance are as follows: Maximal oxygen uptake (V̇O2max): defined as the maximum rate of oxygen consumption measured during an incremental exercise test, or the highest rate at which oxygen can be utilised to power endurance exercise.Lactate threshold: defined as the exercise intensity at which lactate accumulates exponentially in the blood during endurance exercise. This indicates the percentage of V̇O2max that can be maintained without resulting in a drop in power/velocity.Mechanical efficiency: defined as the oxygen uptake or energy utilised to maintain a given power output or velocity.
Dysfunctions of COVID-19
Published in Wenguang Xia, Xiaolin Huang, Rehabilitation from COVID-19, 2021
Oxygen uptake reflects the body’s ability to absorb and consume oxygen, which is determined by the level of oxygen demand in cells and the maximum amount of oxygen transport. Oxygen uptake can be calculated by oxygen uptake into the bloodstream and tissues. Maximal oxygen uptake (VO2max) is the most important index to reflect aerobic capacity and exercise potential. Factors affecting oxygen uptake include oxygen-carrying capacity of blood, cardiac function, peripheral blood flow redistribution, tissue uptake, etc. The relationship between heart rate and oxygen uptake is usually nonlinear in low power motion but becomes nearly linear when the power gradually increases to the maximum. When an age-predicted heart rate is reached during exercise, it usually reflects that the patient has made the most effort and is close to reaching VO2max. The difference between the heart rate predicted by age and the maximum heart rate during exercise is the heart rate reserve. For COVID-19 patients, after correction of hypoxemia, anemia, and hypoproteinemia, tachycardia in calm state and low metabolic equivalent during exercise exceed the predicted value, both of which reflect the patient’s reduced exercise ability.
Football for homeless and socially deprived people
Published in Peter Krustrup, Daniel Parnell, Football as Medicine, 2019
Morten B. Randers, Amy Mendham, Mette K. Zebis, Jannick Marschall, Jens Jung Nielsen, Jincheng Xu, Peter Krustrup
Maximal oxygen uptake is a strong predictor of the risk of cardiovascular disease and early death (Erikssen et al. 1998; Keteyian et al. 2008; Nauman et al. 2017). The large Norwegian HUNT study showed that men with maximal oxygen uptake below the median (44.2 ml min−1 kg−1) had an eight-times-higher risk of cardiovascular disease compared to those in the highest quartile (50.5 ml min−1 kg−1) (Aspenes et al. 2011). For women, risk of cardiovascular disease was five times higher for those below the median (35.1 ml min−1 kg−1) compared to those in the highest quartile (40.8 ml min−1 kg−1), and it was shown that for every 5 ml min−1 kg−1 lowering of maximal oxygen uptake there was a 56% higher prevalence of cardiovascular risk factors (Aspenes et al. 2011).
Oxygen uptake efficiency slope in community-dwelling ambulant stroke survivors during walking and stair climbing: a cross-sectional study
Published in Topics in Stroke Rehabilitation, 2023
Janaine C. Polese, Louise Ada, Raquel de Carvalho Lana, Karina Boson, Iza Faria-Fortini, Luci F. Teixeira-Salmela
Maximal oxygen consumption (VO2 max), i.e. the capacity of an individual to take up and use oxygen during incremental exercise, is the gold standard method for measuring cardiorespiratory fitness.4,8 However, its use may be limited for those who are unable to reach maximum aerobic capacity, such as stroke survivors, due to physical and physiological impairments such as hemiparesis, fatigue, and motivation.9,10 Thus, maximal oxygen uptake might be overestimated, since stroke survivors may not tolerate maximal exercise testing.4 Furthermore, exhaustive exercise tests do not mimic an individuals’ daily life activities. In order to overcome these limitations, the oxygen uptake efficiency slope11 during a submaximal test12 has been proposed as a more appropriate measure of aerobic capacity after stroke.13
Effect of aerobic training on exercise capacity and quality of life in patients older than 75 years with acute coronary syndrome undergoing percutaneous coronary intervention
Published in Physiotherapy Theory and Practice, 2022
Bingying Deng, Xiaoling Shou, Aihua Ren, Xinwen Liu, Qinan Wang, Bozhong Wang, Yan Wang, Ting Yan, Xiaoxia Zhao, Liyue Zhu
Increased maximal oxygen uptake can alleviate patients’ cardiopulmonary symptoms, reduce the myocardial burden and improve functional capacity, and this may lead to improvements in daily physical activities (Yang et al., 2017), which would favorably affect individual’s mental health. This is illustrated by the following results in our study: in the CR group, the SAS and SDS scores were remarkably reduced after the intervention compared to baseline. The finding suggests that CR can significantly mitigate the anxiety and depression, resulting from the illness and relieve discomfort from the change of lifestyle and physical discomfort. Physically active people are less depressed, compared with their sedentary counterparts, and inactive persons who become active are less likely to become depressed (Egger et al., 2008). Consideration of the correlation between physical activity and mental health may partly explain the decreased SAS and SDS scores.
Examination of a new functional firefighter fitness test
Published in International Journal of Occupational Safety and Ergonomics, 2021
Asgeir Mamen, Erna Diana von Heimburg, Harald Oseland, Jon Ingulf Medbø
The HR rose quickly and stayed elevated during the test. Some variations were seen according to the demands of the different tasks. The peak value near the end of the test was 179 bpm. This represents 97% of the peak HR found for the extended NLIA test done to exhaustion. Davis et al. [7] found, on average, 90% of maximal HR in a five-task test taking ≈7 min to finish. Elsner and Kolkhorst [37] reported that the subjects reached 95% of maximal HR (175 bpm) during their screening test. von Heimburg et al. [19] measured the peak HR at the end of a rescue task as 96% of the maximal HR measured during a maximal oxygen uptake test. Bilzon et al. [6] reported HRs of 167–176 (89–92% of maximal HR) for their female participants when they did five 4-min steady-state firefighting tasks. For the males, a somewhat lower value was found. Most tests mentioned here are ‘cold’ tests done at normal external temperature. Lusa et al. [38] performed a 15-min test inside a heat chamber with a temperature of 110 °C. The peak HR there was 95% of the maximal value found for a traditional maximal oxygen uptake test. Thus, firefighters will expectedly work close to their maximum HR in real and simulated firefighting tasks of at least a few minutes in duration.