Dysfunctions of COVID-19
Wenguang Xia, Xiaolin Huang in 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.
Lung cancer
Louis-Philippe Boulet in Applied Respiratory Pathophysiology, 2017
Once the investigation has confirmed the diagnosis of cancer, CT and PET scans are used to determine if the tumor is localized enough to be surgically resected or if it exceeds the extent beyond which it can not be cured by surgery. Currently, this threshold is at stage IIIA and only for cancer non-small cell lung cancer. Surgery for small cell lung cancer is reserved for rare cases of very early stage tumors. Moreover, even if the tumor is resectable given its histologic type and TNM stage, it is still necessary that the patient be medically fit enough to tolerate lung surgery. In particular, respiratory function tests and ventilation/perfusion (V/Q) scintigraphy can predict whether a patient's respiratory reserve will make him or her a candidate for the surgery by calculating the remaining functional lung volumes after the proposed surgery to remove the tumor. With an insufficient lung reserve (predicted forced expiratory volume [FEV] in 1 second of 800 mL or less), resection may be limited or even contraindicated. Similarly, a VO2 max of less than 10 mL O2/kg/min for exercise testing on a cycle ergometer is a predictor of postoperative complications usually making a patient nonoperable.
Psychology in practice
Dominic Upton, Katie Thirlaway in Promoting Healthy Behaviour, 2013
A major benefit of goal-directed behaviour is the possibility of positive feedback. Feedback about goal success can significantly improve subsequent performance, probably by improving self-efficacy. However, for behavioural change, difficult, complex, long-term goals (such as weight loss or fitness) are unlikely to generate immediate positive feedback. This can lead to a reduction in self-efficacy as individuals feel they are not achieving their goal and can lead to individuals giving up and reverting to their original ‘bad habits’. Indeed, research suggests that failing to achieve self-regulatory goals can promote a worsening of original bad habits (Herman and Polivy, 2004). Short-term goals are much easier to link to positive feedback and can improve self-efficacy and help people stick to their change. The majority of health behaviours that people wish to change are highly complex and will require careful planning to develop an appropriate goal-setting strategy. It is generally better to set behavioural goals such as increasing exercise rather than physiological status goals such as increasing VO2 max. Behaviours are more directly under a person’s control than are physiological responses. The key strategies for successful goal setting are presented in Table 2.4.
COVID-19 reduces cardiorespiratory fitness even months after a mild to moderate acute phase: a retrospective cohort study
Published in Infectious Diseases, 2023
Ladislav Štěpánek, Marie Nakládalová, Eliška Sovová, Lubomír Štěpánek, Alena Boriková, Markéta Sovová, Katarína Moravcová, Jaromír Ožana, Libor Jelínek
The obtained results show that with similar mean values at baseline in both subgroups of HCWs, VO2 max decreased statistically significantly between examinations in the subgroup that experienced COVID-19. Mean VO2 max did not change significantly in the subgroup that did not experience COVID-19. VO2 max is the gold standard expression of cardiorespiratory fitness and aerobic capacity, and is also a strong predictor of all-cause and case-specific mortality and morbidity [13]. An individual’s VO2 max should be considered in the context of what is normal for that person. It is known that VO2 max decreases with age and that higher values are observed in men compared to women. Therefore, it is important to have predicted reference values for comparison when assessing VO2 max [14]. In HCWs with a history of COVID-19, the proportion of individuals reaching predicted values decreased between both cardiopulmonary exercise tests, but without statistical significance, which can be attributed to the relatively small number of HCWs in the COVID-19 subgroup. In the control subgroup, however, a slightly greater proportion of HCWs achieved the predicted VO2 max values during the second cardiopulmonary exercise testing compared with the first test.
High-intensity interval training (HIIT) alleviated NAFLD feature via miR-122 induction in liver of high-fat high-fructose diet induced diabetic rats
Published in Archives of Physiology and Biochemistry, 2020
Fatemeh Kalaki-Jouybari, Mehrnoosh Shanaki, Maryam Delfan, Sattar Gorgani-Firouzjae, Soheyla Khakdan
Initially, we allowed all diabetic rats (group 2, HFHFD) to familiarize themselves with a rodent treadmill (15 min, 0% grade). Maximal oxygen uptake (VO2 max) was evaluated as previously mentioned (Chavanelle et al.2017). Next, we divided the diabetic rats into three groups: (1) Diabetic control group (HFHFD + DC, n = 6) rats did not perform any exercise activities. However, to create the same conditions as the other study rats; we placed the HFHFD + DC rats on a stationary treadmill five times per week for 10–15 min each session. (2) HFHFD + CET (n = 6) rats participated in exercise sessions that consisted of 5 min running at 30%–40% VO2 max for the warm up period followed by 30 min of running at 60%–65% VO2 max, and a 5 min cool down period of running at 30%–40% VO2 max for each session (Ghareghani et al.2017). (3) HFHFD + HIIT (n = 6) rats began their sessions with a 5 min warm up period of running at 30%–40% VO2 max, followed by five cycles of alternating high-intensity and low-intensity intervals (2 min at 85%–90% VO2 max and 2 min at 30%–40% VO2 max), and a final 3 min cooling down period of running at 30%–40% VO2 max (Cassidy et al.2017).
Training with FES-assisted cycling in a subject with spinal cord injury: Psychological, physical and physiological considerations
Published in The Journal of Spinal Cord Medicine, 2020
Charles Fattal, Benoit Sijobert, Anne Daubigney, Emerson Fachin-Martins, Brigitte Lucas, Jean-Marie Casillas, Christine Azevedo
In recent years, several innovative techniques have been developed to train the mobility of the lower limbs in SCI rehabilitation programs such as functional electrical stimulation (FES). Cycle ergometers can be motorized and thus offer only passive mobilization. Yet if the motorized function is turned off, applying FES to the glutei, quadriceps and hamstrings makes it possible to reproduce pedaling movements to which resistance can be applied. Studies have indeed suggested the promising effects on body composition and bone remodeling especially when training begins early, lasts sufficiently long and is conducted at high intensity.5,6 The cardiovascular benefit has been suggested by the increase in VO2max and the drop in low-density lipoprotein (LDL) cholesterol.7,8 In one study, 4 weeks of training was enough to increase muscle volume as reflected by changes in the muscle cross-sectional area, from a minimum of 15–17% for some muscles and a maximum of 25% for others.9
Related Knowledge Centers
- Breathing
- Cardiac Stress Test
- Cardiorespiratory Fitness
- Endurance
- Endurance Training
- Oxygen
- Respiration
- Physical Fitness
- Treadmill
- Stationary Bicycle