**4.2 Psychosocial support**

The burden of advanced respiratory disease is exacerbated by anxiety, sadness, coping issues, and a lack of self-efficacy. Despite the lack of evidence to support psychosocial therapies as a single therapeutic modality in COPD patients, complete PR programs that include these types of interventions reap advantages [10].

Comprehensive PR leads to small- to moderate-scale improvements in anxiety and dyspnea when compared to usual therapy, according to research. PR programs differ in their use of psychosocial and behavioral interventions, but they frequently contain educational sessions or support groups that concentrate on coping mechanisms and stress management. These support groups also promote participation from patients' loved ones and friends. Patients with severe mental illness should be referred for the proper treatment [5, 11].

### **4.3 Exercise training**

#### *4.3.1 Exercise training for upper and lower extremities*

A crucial component of PR programs is exercise training. Exercise training has been demonstrated to be the most effective method for improving muscle strength. It is also likely to increase motivation for exercise, reduce mood disorders, reduce symptoms, and improve cardiovascular health. Endurance and resistance training should be a part of PR programs, according to recent major guidelines, which are the essential components of exercise training programs for COPD patients. Although none of the recommendations give clear, accurate, and precise recommendations for full exercise training, they all support endurance training at least three to five times per week at a rate more than 60% of one's maximum heart rate. Although it is advised to exercise for at least 20 minutes and for a target program duration of up to 12 weeks, there is disagreement on initial workloads, increasing the exercise load, or program duration [5, 11].

PR requires a comprehensive workout program that includes upper- and lowerextremity endurance training as well as strength training. COPD is a disease of the peripheral muscles, characterized by a loss of mass, changes in fiber-type distribution, and a reduction in metabolic capacity, all of which contribute to exercise intolerance. Exercise training may be able to help with these issues. Higher degrees of exercise training are linked to a stronger physiologic training impact, dose-dependent changes in oxidative enzymes in limb muscles, and increased exercise capacity [11].

Exercise training is based on the main concepts of intensity (higher intensity produces better results), specificity (only the muscles that have been trained show an effect), and reversibility (only the muscles that have been trained show an effect) (cessation of regular exercise training results in a decrease in training effect) [6]. Although patients with COPD often have ventilatory limitations to maximal exercise, high training targets can nevertheless have a physiologic training impact. Exercise intensity of 60 to 80% of the patient's peak work rate is often feasible [5].

Another crucial aspect of exercise training is strength training, which also offers potential advantages. Strength training can be helpful for patients who cannot withstand intense exercise regimens. Some patients might be able to train at higher intensities by maximizing bronchodilation, doing interval training (i.e. switching between high and low intensities), and taking oxygen supplements [4, 5]. The optimal training duration has not been determined; rather, it is based on how each patient is doing. A successful PR program should continue at least 8 weeks (with three to four sessions each week), following the GOLD (Global Initiative for Chronic Obstructive Lung Disease) criteria, but the longer the better [12].

Although, high-intensity exercise training is effective and ideal, the rate of implementation and continuation is low especially in home-based PR setting. Therefore, low-intensity exercise training is a realistic choice in home-based PR setting [5].

### *4.3.2 Inspiratory muscle training (IMT)*

COPD patients have respiratory muscle weakness, which contributes to hypercapnia, dyspnea, nocturnal oxygen desaturation, and reduced walking distance. Diaphragm work is increased in COPD patients during exercise, and COPD patients use a greater proportion of the maximum inspiratory pressure (PI max) than healthy subjects [5]. This pattern of breathing is closely related to the dyspnea sensation during exercise and might potentially induce respiratory muscle fatigue [13].

Respiratory muscle training is a part of rehabilitation in selected patients with COPD. Respiratory strength has been found to correlate with improved pulmonary function, reduction of dyspnea severity, improved exercise tolerance, and enhanced functionality and quality of life [9]. By boosting type II fibers, which leads to a decrease in inspiratory time and an increase in expiratory time, inspiratory muscle training (IMT) is thought to help the diaphragm contract. Since hyperinflation is anticipated to eventually decrease, IMT is believed to have an effect on dyspnea without significantly changing inspiratory pressure [13, 14].

#### *4.3.3 New advances in the exercise training*

There have been numerous new developments in exercise training in recent years, which is a crucial part of PR. In patients with COPD and physical comorbidities, water-based exercise training has been demonstrated to be noticeably more successful than land-based exercise training and control in raising peak and endurance exercise capacity and improving health-related quality of life (HRQoL) [4, 5]. Compared to level walking, downhill walking causes higher quadriceps low-frequency fatigue in COPD patients, who also experience reduced cardiorespiratory expenses [15]. It has been proposed that downhill walking can be a beneficial component of a thorough rehabilitation program [16]. It has also been demonstrated that eccentric exercise therapy, such as downhill walking, improves bodily functions and HRQoL and increases the size of the thigh muscles. Wholebody vibration has been proven to be a useful tool for strengthening muscles and as a potential means of reducing wasting and weakening. Patients with COPD who are bedridden and unable to receive physical physiotherapy might gain anything. The use of whole-body vibration proved safe and practical, and the method results in more energy use [5, 14].

#### **4.4 Nutritional support**

Patients with COPD who are underweight have worse lung health, less diaphragmatic mass, less exercise tolerance, and a greater mortality rate than those who are properly fed. Nutritional supplementation could be beneficial for their comprehensive care [6] to evaluate how dietary supplementation affects anthropometric measurements, lung function, strength, endurance, functional exercise capacity, and HRQoL in COPD. If a benefit is seen, subgroup analysis should be done to determine the treatment plans and subpopulations that show the most promise [5].
