**4. Physical exercise in chronic illness**

### **4.1 General impact**

An important risk factor for many chronic diseases is physical inactivity, which can be prevented and treated. Chronic physical inactivity has been linked to an increased incidence of adverse CV events and a greater death rate in patients with peripheral arterial disease and dialysis. Simple frequent physical activity can serve as a springboard for healthy living and deliver substantial health benefits [21].

Daily PA and PE, according to current studies, can help avoid chronic diseases (such as cardiovascular disease, type 2 diabetes, obesity, and cancer) and mortality, as well as serve as a primary disease prevention strategy. Patients with high blood pressure and known cardiovascular diseases can potentially benefit metabolically and cardiovascularly from moderate-intensity activities [22–24]. A reduction in mortality risk may also result from improved and sustained physical fitness over time [10]. When a chronic illness is diagnosed, including PA and PE in the disease management strategy, improves the patient's overall health. PA and regular PE improve QoL and lengthen life when used in disease prevention or treatment [25].

Pre-dialysis patients with severe CKD suffer from decreased physical function and performance due to a variety of factors, including renal function decline, arteriosclerosis, and chronic inflammation [26]. Pre-dialysis CKD patients with improved physical performance and higher PA levels have lower overall mortality and CVD risk [27]. Patients with CKD benefit greatly from exercise training, which includes both aerobic and resistance activities, as well as increased muscle strength and lower blood pressure (BP) [26]. PE also benefits dialysis patients' physical health by improving CV function, blood pressure, muscle strength, and nutritional status, as well as improving dialysis quality [28]. For HD patients, PA in everyday life has a greater impact on QoL than it does in the general population [29].

## **4.2 Effect on physiological parameters**

Muscle mass, strength, IS, mitochondrial content, and regeneration capacity can all be improved with PA. It is common to employ resistance training to build muscle and improve overall strength. As a result, your muscles get bigger and stronger, while your overall fitness increases. This includes considerable gains in myofibre and whole-muscle growth, strength, quality, and physical performance, or the prevention of these decreases.

Patients with cardiovascular disease benefit from regular PE because it lowers blood pressure, reduces resting heart rate, and raises atherogenic marker levels while also enhancing physiological cardiac hypertrophy. There are many benefits to losing weight, including decreased visceral adiposity, lowered cholesterol, HDL-C, and blood pressure (BP), as well as improved maximum oxygen consumption (VO2max) through either diet or exercise alone, or a combination of the two. Workout has been found to improve glucose homeostasis, endothelial function, blood pressure (BP), and HDL-C levels regardless of weight without affecting weight. Those who are overweight or have type 2 diabetes are at greater risk of cardiovascular disease, and regular exercise reduces that risk or severity [30, 31].

Regular physical activity and/or aerobic fitness are linked to better IS performance. Insulin resistance may usually be ameliorated and, in some cases, completely reversed, using PE interventions. Both acute and chronic effects of PA on IS have been documented in the literature. Acute effects can be seen during and/ or for up to 72 hours after a single bout of physical activity and are directly linked to it. If these bouts are repeated on a regular basis, long-term chronic IS enhancement occurs, resulting in better glucose management than what is generally seen in people who are less active. There appears to be a dosage response with an increase in PA of 500 kcal/week, reducing the incidence of T2DM by about 9% [32]. Exercise's ability to improve IS and glucose absorption in the elderly is important [33]. Having a healthy lifestyle that includes moderate-intensity aerobic activity and/or PA on 3–5 days a week for at least 30 minutes has been linked to better IS and glycaemic management.

PE enhances the peroxisome proliferator-activated receptor co-activator 1 in cardiomyocytes after both endurance and resistance exercise (PGC-1) [33]. By improving mitochondrial fatty acid oxidation (the primary substrate used by healthy myocardium), PE also improves ATP synthesisation performance. Preventing CV dysfunctions in obese people, through PE-induced improvements in mitochondrial function, Is well documented. The reconfiguration of the mitochondrial network (fusion, fission, and autophagy) that occurs during exercise has also been found to improve mitochondrial function/efficiency [33].

#### **4.3 Effect on general well-being**

Recent research reveals that physical activity (PE) provides a number of benefits for people of all ages, and that it improves psychological well-being and quality of life (QoL). Physical education (PE) boosts self-efficacy, task orientation, and perceived competence in youngsters. Physical activity has been related to improved health outcomes in both children and adults, including a more positive self-image and a better mood. Last but not the least, for the elderly, physical activity promotes security, social connections, and mental health [34].

PE increases one's quality of life by interacting with biological and psychological systems. Higher cerebral blood flow improves oxygen delivery to brain tissue and allows for more oxygen consumption. Other biological causes include decreased muscular tension and increased endocannabinoid receptor numbers in the

bloodstream, among others. The changing amounts of neurotransmitters caused by the phenomenon of neuroplasticity may also have an impact on one's overall wellbeing. When someone has a traumatic brain injury, their levels of neurotransmitters such as serotonin and endorphins rise. By emphasising the sense of control, selfefficacy, and competency, PE boosts students' self-esteem and self-concept while also creating a positive social synergy [34].

The benefits of regular and moderate physical activity extend beyond improved general health to lowered coronary heart disease (CHD) risk. T2DM patients who have PE experience a drop in their blood sugar and systolic blood pressure, which reduces their risk of developing DM-related complications, dying from the disease, or suffering from a heart attack. Because it reduces weight, PE lowers the risk factors for developing type 2 diabetes. Physical inactivity is linked to obesity and diabetes mellitus (DM), as well as a higher incidence and mortality from cancer (e.g. breast, endometrial). So PA and PE are linked to improved well-being and lowered mortality risk [35].

#### **4.4 Improving physical fitness and function**

Exercise therapy improves fitness and reduces the risk of illness consequences in people with chronic diseases [36]. Regular PA has been shown in these cases to enhance the human physique, lipid profiles (e.g. by decreasing the levels of total cholesterol, raising HDL-C levels, and diminishing the low-density lipoprotein [LDL]-to-HDL ratios), glucose homeostasis, autonomic tone, IS, coronary blood flow and endothelial function; improve cardiac function; and reduce BP, systemic inflammation, and blood coagulation. Chronic inflammation is a prominent cause in the majority of chronic illnesses, according to high levels of inflammatory markers such as C-reactive protein, and PE has been found to help avoid them [37].

Premature death is reduced when one's physical fitness improves, whereas it is increased when one's fitness deteriorates. Even a little increase in physical fitness has been shown to lead to a considerable decrease in risk. The health status of previously inactive adults improved significantly when their physical fitness was modestly increased [37]. Regular physical exercise reduces weight gain, obesity, coronary artery disease, type 2 diabetes, and Alzheimer's disease over time [38].

Even in the absence of increases in aerobic fitness, an improvement in health status indices can be detected as PA levels rise. That is especially true in the elderly, where frequent PA can minimise the risk of chronic illness and impairment while having no discernible effect on conventional physiologic performance metrics such as oxidative potential and cardiac output. PA can improve musculoskeletal fitness as well as cardiovascular fitness. According to a growing body of evidence, improved musculoskeletal fitness is linked to greater overall health and a lower risk of chronic illness and disability.

Health-related quality of life and hospitalisation, surgical results, and death are all influenced by one's ability to execute fundamental physical duties. Patients on haemodialysis benefit from PA because it increases their bodily function and physical ability, which lowers their blood pressure and increases their oxygen intake to their maximum potential [39]. The number of 30-second sit-to-stand tests (STS) increased after exercise began, and the time it took to complete the 8-foot timed up-and-go tests decreased, with no evidence of exercise-related unpleasant sensations. Some patients underwent a low-intensity home walking programme, while others were assigned at random to a slower-moving control group [40]. As a result, PE helps people with CKD become more fit and functional.

*Effect of Exercise on Health-Related Quality of Life in Patients with End-Stage Renal Disease DOI: http://dx.doi.org/10.5772/intechopen.101133*

#### **4.5 Patients with CKD**

According to a recent meta-analysis, exercise treatment improved eGFR while simultaneously lowering blood pressure, BMI, and systolic blood pressure in CKD patients who were not on dialysis. Short-term exercises have been shown to lower TG levels as well [41]. Another systematic review and meta-analysis on individuals with comparable conditions found that frequent exercise increased peak oxygen consumption more than standard treatment and improved physical and walking abilities [26].

The effectiveness of a systematic physical exercise programme in patients with HD was examined over the course of a long trial, which also looked at patient compliance and the study's clinical outcomes. Exercise ability, strength, and QoL improved significantly over the course of a year in individuals with high and moderate compliance [42]. Recent meta-analysis shows that exercise improves HRQoL and aerobic capacity in people with ESRD undergoing HD. Patients' physical conditions improved as a result of doing aerobic or combination exercises for eight to 52 weeks, three times each week, according to the authors [43].
