**3. Types of exercises**

Physical activity is defined as any bodily movement produced by skeletal muscles that results in energy expenditure beyond resting energy expenditure (Thompson et al., 2003). Information on the importance of physical activity in COPD has grown, especially in the last few years, although major questions remain to be answered. The present chapter aims to provide an update on the most important studies of physical activity in COPD (Esteban, 2009).

Findings from meta-analysis of pulmonary rehabilitation strongly supports that exercise training as part of treatment of patients with COPD should last at least four weeks (Lacasse, Goldstein, Lasserson, & Martin, 2006). Exercise training should be available to people with COPD, because it improves breathlessness, quality of life, exercise tolerance and functional ability (Lacasse et al., 2006). Physical therapists are crucial to the delivery of rehabilitation because of their training in exercise and movement therapies (Garrod & Lasserson, 2007).

The primary goal of the rehabilitation programs is to restore the patient to the highest possible level of independent function (Ries et al., 2007). This goal is accomplished by

Types of Physical Exercise Training for COPD Patients 359

There is not consensus on the optimal method of resistance training (callisthenics, resistance weight training, isometrics or isokinetic-type training) in patients with COPD. Each type produces strength gains highly specific to the type of training. There are no studies that compared different intensities of resistance training in patients with COPD. It is recommended to use (lower limb) resistance training according to ACSM (two or three times a week) ("ACSM", 1998a; "ACSM", 1998b; Garber et al., 2011). Exercises should be performed at 60-80% of the first repetition maximum (RM), resistance exercises should train 8-10 exercises involving the major muscle groups in bouts of 8-15 repetitions at least 30 minutes a day of moderate-intensity activity on two or three non-consecutive days each week (Nelson et al., 2007). Multiple sets of repetitions (2-5 sets) provide greater benefit (Langer et al., 2009). Resistance activities include a progressive-weight training program,

Given that muscle weakness is a common problem in this population, progressive resistance exercise represents a beneficial treatment for improvements in muscle strength (O´Shea, Taylor, & Paratz, 2009). Moreover, improvements in muscle strength can be obtained when progressive resistance exercise is conducted alone or in combination with aerobic training, indicating that it can be successfully performed in conjunction with other training types

Careful consideration is also required when prescribing progressive resistance exercise programs for people with COPD who have comorbid health conditions (O´Shea, Taylor, & Paratz, 2004). Therefore, progresive resitance exercise may not be appropriate for all people with COPD attending pulmonary rehabilitation, and it is recommended that prescription be

It is essential to educate the patient about the importance of the training program begining with an initial phase: warming up and stretching (Table 2 Session outline). The central part consists in aerobic training (endurance or interval exercise), resistance training and breathing retraining. Finally, the sessions finish with stretching and relaxation exercises.

Initial phase Central phase Final phase

It is recommended to apply training strategies that enable patients to resume participation in a rehabilitation programme after an acute exacerbation as soon as possible (Puhan, Scharplatz, Troosters, Walters, & Steurer, 2009). Resistance training and interval training are best suited for early reactivation of patients. Moreover, arm exercises in patients with COPD were shown to increase arm muscle force (Epstein et al., 1997) and reduce symptoms of dyspnea and fatigue during arm activities (Bauldoff, Hoffman, Sciurba, & Zullo, 1996).

Patient education is included as an important recommendation in current clinical practice guidelines for COPD *(GOLD,* 2010; Celli, MacNee, & ATS/ERS Task Force, 2004) Education should be an integral component of pulmonary rehabilitation (Ries et al., 2007). Moreover,

\*Stretching

\*Relaxation exercises

\*Aerobic training (Endurance or Interval) \*Resistance training \*Breathing retraining

done with therabands (wrist or ankle weights) or progressive weight.

during pulmonary rehabilitation (O´Shea, Taylor, & Paratz, 2009).

targeted to the individual (Storer, 2001).

\*Stretching \*Warming up

Table 2. Session outline

helping patients become more physically active, and to learn more about their disease, treatment options, and how to cope. Within the program of rehabilitation, the physiotherapeutic intervention is responsible for various treatment phases (specifically physical exercise training, peripheral and respiratory muscle training, and breathing exercises) (Langer et al., 2009).

Aerobic exercise is the main non-pharmacological treatment better tolerated by patients with COPD (Martín-Valero, Cuesta-Vargas, & Labajos-Manzanares, 2010). Exercise training is one of the key components of pulmonary rehabilitation. The exercise prescription for the training program is guided by the following three parameters: intensity; frequency; and duration.

The standarized criterions on intervention period, dose, intensity of physical exercises in COPD patients is needed. Seven (Coppoolse et al., 1999; Kurabayashi et al., 2000; O'Shea, Taylor, & Paratz, 2004; Puente-Maestu, Sanz, Sanz, Cubillo et al., 2000; Puente-Maestu, Sanz, Sanz, Ruiz de Ona et al., 2000; Wadell, Sundelin, Henriksson-Larsen, & Lundgren, 2004; Wijkstra et al., 1995) agreed with the criteria of the American College of Sports Medicine (ACSM) (Garber et al., 2011) for the intervention period and number of sessions varied from eight weeks in the majority on trials to twelve weeks in two trials and from two to four sessions a weeks. Therefore, the number sessions a week were at least between two or four sessions a week. Only one trial (Wijkstra et al., 1995) took into account, that patients had to practise twice a day for an individualised protocol, for 0 to 5 hours the first three months and then once a day only for 0-5. The time of sessions is variable in these seven articles with a minimum of 20 minutes up to 60 minutes because two articles do not talk about the time of sessions.

According to the recommendations of the American Association of Cardiovascular and Pulmonary Rehabilitation (AACVPR), *high-intensity training targets* have been operationally defined to be at least 60 to 80% of the peak work rate achieved in an incremental maximum exercise test. The intensity of the training sessions in five articles (Coppoolse et al., 1999; Puente-Maestu, Sanz, Sanz, Cubillo et al., 2000; Puente-Maestu, Sanz, Sanz, Ruiz de Ona et al., 2000; Wadell, Sundelin, Henriksson-Larsen, & Lundgren, 2004; Wijkstra et al., 1995) showed that the goal is 60-90% of heart rate maximum (HRmax) set by the ACSM for improving aerobic fitness ("American college of sports medicine position stand. exercise and physical activity for older adults,"1998a; "American college of sports medicine position stand. The recommended quantity and quality of exercise for developing and maintaining cardiorespiratory and muscular fitness, and flexibility in healthy adults,"1998b)

Exercise training intervention can be adapted to the individual exercise limitations of the patient (Troosters, Gosselink, Langer, & Decramer, 2007). Troosters et al. review focused on different training types (endurance, interval and resistance training) (Troosters et al., 2007). In this chapter regarding types of exercise training intervention, it has been divided into aerobic and resistance training types. Aerobic exercise training for older people should have a target intensity of 50-85% of the oxygen uptake reserve – a range that includes both moderate exercise (minimum of 30 minute five days a week) or vigorous exercise (20 minutes three days each week)(Garber et al., 2011).

Resistance training is an ideal intervention for patients with peripheral muscle weakness and pronounced symptoms of dyspnea during exercise (O´Shea, Taylor, & Paratz, 2004).

helping patients become more physically active, and to learn more about their disease, treatment options, and how to cope. Within the program of rehabilitation, the physiotherapeutic intervention is responsible for various treatment phases (specifically physical exercise training, peripheral and respiratory muscle training, and breathing

Aerobic exercise is the main non-pharmacological treatment better tolerated by patients with COPD (Martín-Valero, Cuesta-Vargas, & Labajos-Manzanares, 2010). Exercise training is one of the key components of pulmonary rehabilitation. The exercise prescription for the training program is guided by the following three parameters: intensity; frequency; and

The standarized criterions on intervention period, dose, intensity of physical exercises in COPD patients is needed. Seven (Coppoolse et al., 1999; Kurabayashi et al., 2000; O'Shea, Taylor, & Paratz, 2004; Puente-Maestu, Sanz, Sanz, Cubillo et al., 2000; Puente-Maestu, Sanz, Sanz, Ruiz de Ona et al., 2000; Wadell, Sundelin, Henriksson-Larsen, & Lundgren, 2004; Wijkstra et al., 1995) agreed with the criteria of the American College of Sports Medicine (ACSM) (Garber et al., 2011) for the intervention period and number of sessions varied from eight weeks in the majority on trials to twelve weeks in two trials and from two to four sessions a weeks. Therefore, the number sessions a week were at least between two or four sessions a week. Only one trial (Wijkstra et al., 1995) took into account, that patients had to practise twice a day for an individualised protocol, for 0 to 5 hours the first three months and then once a day only for 0-5. The time of sessions is variable in these seven articles with a minimum of 20 minutes up to 60 minutes because two articles do not talk about the time of

According to the recommendations of the American Association of Cardiovascular and Pulmonary Rehabilitation (AACVPR), *high-intensity training targets* have been operationally defined to be at least 60 to 80% of the peak work rate achieved in an incremental maximum exercise test. The intensity of the training sessions in five articles (Coppoolse et al., 1999; Puente-Maestu, Sanz, Sanz, Cubillo et al., 2000; Puente-Maestu, Sanz, Sanz, Ruiz de Ona et al., 2000; Wadell, Sundelin, Henriksson-Larsen, & Lundgren, 2004; Wijkstra et al., 1995) showed that the goal is 60-90% of heart rate maximum (HRmax) set by the ACSM for improving aerobic fitness ("American college of sports medicine position stand. exercise and physical activity for older adults,"1998a; "American college of sports medicine position stand. The recommended quantity and quality of exercise for developing and maintaining

Exercise training intervention can be adapted to the individual exercise limitations of the patient (Troosters, Gosselink, Langer, & Decramer, 2007). Troosters et al. review focused on different training types (endurance, interval and resistance training) (Troosters et al., 2007). In this chapter regarding types of exercise training intervention, it has been divided into aerobic and resistance training types. Aerobic exercise training for older people should have a target intensity of 50-85% of the oxygen uptake reserve – a range that includes both moderate exercise (minimum of 30 minute five days a week) or vigorous exercise (20

Resistance training is an ideal intervention for patients with peripheral muscle weakness and pronounced symptoms of dyspnea during exercise (O´Shea, Taylor, & Paratz, 2004).

cardiorespiratory and muscular fitness, and flexibility in healthy adults,"1998b)

minutes three days each week)(Garber et al., 2011).

exercises) (Langer et al., 2009).

duration.

sessions.

There is not consensus on the optimal method of resistance training (callisthenics, resistance weight training, isometrics or isokinetic-type training) in patients with COPD. Each type produces strength gains highly specific to the type of training. There are no studies that compared different intensities of resistance training in patients with COPD. It is recommended to use (lower limb) resistance training according to ACSM (two or three times a week) ("ACSM", 1998a; "ACSM", 1998b; Garber et al., 2011). Exercises should be performed at 60-80% of the first repetition maximum (RM), resistance exercises should train 8-10 exercises involving the major muscle groups in bouts of 8-15 repetitions at least 30 minutes a day of moderate-intensity activity on two or three non-consecutive days each week (Nelson et al., 2007). Multiple sets of repetitions (2-5 sets) provide greater benefit (Langer et al., 2009). Resistance activities include a progressive-weight training program, done with therabands (wrist or ankle weights) or progressive weight.

Given that muscle weakness is a common problem in this population, progressive resistance exercise represents a beneficial treatment for improvements in muscle strength (O´Shea, Taylor, & Paratz, 2009). Moreover, improvements in muscle strength can be obtained when progressive resistance exercise is conducted alone or in combination with aerobic training, indicating that it can be successfully performed in conjunction with other training types during pulmonary rehabilitation (O´Shea, Taylor, & Paratz, 2009).

Careful consideration is also required when prescribing progressive resistance exercise programs for people with COPD who have comorbid health conditions (O´Shea, Taylor, & Paratz, 2004). Therefore, progresive resitance exercise may not be appropriate for all people with COPD attending pulmonary rehabilitation, and it is recommended that prescription be targeted to the individual (Storer, 2001).

It is essential to educate the patient about the importance of the training program begining with an initial phase: warming up and stretching (Table 2 Session outline). The central part consists in aerobic training (endurance or interval exercise), resistance training and breathing retraining. Finally, the sessions finish with stretching and relaxation exercises.


Table 2. Session outline

It is recommended to apply training strategies that enable patients to resume participation in a rehabilitation programme after an acute exacerbation as soon as possible (Puhan, Scharplatz, Troosters, Walters, & Steurer, 2009). Resistance training and interval training are best suited for early reactivation of patients. Moreover, arm exercises in patients with COPD were shown to increase arm muscle force (Epstein et al., 1997) and reduce symptoms of dyspnea and fatigue during arm activities (Bauldoff, Hoffman, Sciurba, & Zullo, 1996).

Patient education is included as an important recommendation in current clinical practice guidelines for COPD *(GOLD,* 2010; Celli, MacNee, & ATS/ERS Task Force, 2004) Education should be an integral component of pulmonary rehabilitation (Ries et al., 2007). Moreover,

Types of Physical Exercise Training for COPD Patients 361

Fig. 4. Endurance tasks taken from "Manual de Rehabilitación Respiratoria para personas

frequency of training is the same as with continuous training (Langer et al., 2009).

training at the recommended intensities. Short high intensity (at least 70-80% of peak work rate) exercise bouts of 30-180 seconds are necessary during interval training. Recommended

Only one article (Puente-Maestu, Sanz, Sanz, Cubillo et al., 2000) showed that patients responded to supervised training with incremented loads also changed their ventilatory pattern to deeper, slower breathing. Therefore, improved ventilation this type of incremental training also tended to be more efficient with an average decrease in dead space. Perhaps, the quality of life questionnaires are not sensitive tools to detect changes in the functional variables of disease progression. The changes produced by aerobic physical training in COPD do not have clinical relevance, but they are a success because it slows

Most patients with severe COPD are not able to sustain a continuous exercise protocol. For these patients, interval exercise represents an alternative because it offers the same benefit as high-intensity exercise. Besides, incremental exercise is better tolerated, as expressed by fewer breaks during the rehabilitation program and better adherence to exercise protocols (Puhan MA et al., 2006). Therapeutic intervention can be done in or out of water; the next

This intervention is known for its power of prevention and treatment in different conditions, although not considered part of standard pulmonary rehabilitation. Therapeutic aquatic exercise intervention is a discipline that includes hydrotherapy, spa therapy, balneotherapy and physiotherapy, and is used for the prevention and treatment of diseases through water (Geytenbeek, 2008). Hydrotherapy is defined as a complementary therapy that uses the temperature and pressure of water as a therapeutic agent at a given temperature

section explains the therapeutic aquatic exercise intervention.

**3.2 Therapeutic aquatic exercise intervention** 

con EPOC".

down disease progression.

(Geytenbeek, 2002).

education should include information on collaborative self-management and prevention and treatment of exacerbation. So, patient education interventions are necessary to ensure long-term maintenance of treatment effects. Studies with successful results in chronically ill adults both used physical activity self-monitoring (pedometers or diaries) and applied behavioural strategies to increase patient´s self efficacy and self-regulatory skills (Conn, Hafdahl, Brown, & Brown, 2008). It is necessary to initiate and maintain physical activity behaviour change during and after supervised physical exercise training programs. Rose et al., (Baraniak & Sheffield, 2011; Rose et al., 2002) evaluated psychosocial interventions to treat anxiety and panic in patients with COPD; however the data indicated that there were no changes in cognitive function. Overall, the educational intervention may have facilitated aspects of program adherence.

#### **3.1 Continuous or incremental aerobic exercise**

In this section different types of physical exercise training that can be applied to improve exercise performance in patients with COPD are presented. The authors have compared programmes with constant load training and incremental load training in COPD patients. There is high level evidence that aerobic training is effective for aerobic capacity and there is moderate evidence that interval training is effective for strength, endurance, functionality and psychosocial parameters (Normandin et al., 2002).

#### *Endurance or continuous training*

Supervised continuous training is recommended for patients in all stages of the disease who are able to perform continuous training of at least moderate intensity. Training frequency should be three times weekly in the first weeks of the exercise programme (Langer et al., 2009). Patients with severe symptoms of dyspnea during exercise are frequently not capable of performing high-intensity (70 to 80% of the peak work rate) continuous type training (Casaburi et al., 1997; Maltais et al., 1997). It seems that moderate intensity continuous training (50 to 60% of the peak work rate or 5-6 out of 10 according to the modified Borg Scale) is minimally required to achieve changes in physical fitness. Improvements in healthrelated quality of life after training at moderate intensities were comparable with those observed after high intensity training (Puente-Maestu, Sanz, Sanz, Cubillo et al., 2000).

Lower extremity exercise training at higher exercise intensity produces greater physiologic benefits than lower intensity training in patients with COPD. Moreover, both low-intensity and high-intensity exercise training produce clinical benefits for patients with COPD (Ries, 2008).

Two categories of tasks can be found during everyday activities, endurance and strength tasks. Endurance tasks require repetitive actions over an extended period of time (walking, cycling and swimming) as shown in figure 4. While strength tasks require explosive performance over short time periods (jumping, lifting weights, sprinting)(Ries et al., 2007). The addition of a strength-training component to a program of pulmonary rehabilitation increases muscle strength and muscle mass (Ries, 2008).

#### *Interval training*

Interval training is recommended as an alternative to continuous training in patients with severe symptoms of dyspnea due to the fact that they are unable to sustain continuous

education should include information on collaborative self-management and prevention and treatment of exacerbation. So, patient education interventions are necessary to ensure long-term maintenance of treatment effects. Studies with successful results in chronically ill adults both used physical activity self-monitoring (pedometers or diaries) and applied behavioural strategies to increase patient´s self efficacy and self-regulatory skills (Conn, Hafdahl, Brown, & Brown, 2008). It is necessary to initiate and maintain physical activity behaviour change during and after supervised physical exercise training programs. Rose et al., (Baraniak & Sheffield, 2011; Rose et al., 2002) evaluated psychosocial interventions to treat anxiety and panic in patients with COPD; however the data indicated that there were no changes in cognitive function. Overall, the educational intervention may have facilitated

In this section different types of physical exercise training that can be applied to improve exercise performance in patients with COPD are presented. The authors have compared programmes with constant load training and incremental load training in COPD patients. There is high level evidence that aerobic training is effective for aerobic capacity and there is moderate evidence that interval training is effective for strength, endurance, functionality

Supervised continuous training is recommended for patients in all stages of the disease who are able to perform continuous training of at least moderate intensity. Training frequency should be three times weekly in the first weeks of the exercise programme (Langer et al., 2009). Patients with severe symptoms of dyspnea during exercise are frequently not capable of performing high-intensity (70 to 80% of the peak work rate) continuous type training (Casaburi et al., 1997; Maltais et al., 1997). It seems that moderate intensity continuous training (50 to 60% of the peak work rate or 5-6 out of 10 according to the modified Borg Scale) is minimally required to achieve changes in physical fitness. Improvements in healthrelated quality of life after training at moderate intensities were comparable with those observed after high intensity training (Puente-Maestu, Sanz, Sanz, Cubillo et al., 2000).

Lower extremity exercise training at higher exercise intensity produces greater physiologic benefits than lower intensity training in patients with COPD. Moreover, both low-intensity and high-intensity exercise training produce clinical benefits for patients with COPD (Ries,

Two categories of tasks can be found during everyday activities, endurance and strength tasks. Endurance tasks require repetitive actions over an extended period of time (walking, cycling and swimming) as shown in figure 4. While strength tasks require explosive performance over short time periods (jumping, lifting weights, sprinting)(Ries et al., 2007). The addition of a strength-training component to a program of pulmonary rehabilitation

Interval training is recommended as an alternative to continuous training in patients with severe symptoms of dyspnea due to the fact that they are unable to sustain continuous

aspects of program adherence.

*Endurance or continuous training* 

2008).

*Interval training* 

**3.1 Continuous or incremental aerobic exercise** 

and psychosocial parameters (Normandin et al., 2002).

increases muscle strength and muscle mass (Ries, 2008).

Fig. 4. Endurance tasks taken from "Manual de Rehabilitación Respiratoria para personas con EPOC".

training at the recommended intensities. Short high intensity (at least 70-80% of peak work rate) exercise bouts of 30-180 seconds are necessary during interval training. Recommended frequency of training is the same as with continuous training (Langer et al., 2009).

Only one article (Puente-Maestu, Sanz, Sanz, Cubillo et al., 2000) showed that patients responded to supervised training with incremented loads also changed their ventilatory pattern to deeper, slower breathing. Therefore, improved ventilation this type of incremental training also tended to be more efficient with an average decrease in dead space. Perhaps, the quality of life questionnaires are not sensitive tools to detect changes in the functional variables of disease progression. The changes produced by aerobic physical training in COPD do not have clinical relevance, but they are a success because it slows down disease progression.

Most patients with severe COPD are not able to sustain a continuous exercise protocol. For these patients, interval exercise represents an alternative because it offers the same benefit as high-intensity exercise. Besides, incremental exercise is better tolerated, as expressed by fewer breaks during the rehabilitation program and better adherence to exercise protocols (Puhan MA et al., 2006). Therapeutic intervention can be done in or out of water; the next section explains the therapeutic aquatic exercise intervention.

#### **3.2 Therapeutic aquatic exercise intervention**

This intervention is known for its power of prevention and treatment in different conditions, although not considered part of standard pulmonary rehabilitation. Therapeutic aquatic exercise intervention is a discipline that includes hydrotherapy, spa therapy, balneotherapy and physiotherapy, and is used for the prevention and treatment of diseases through water (Geytenbeek, 2008). Hydrotherapy is defined as a complementary therapy that uses the temperature and pressure of water as a therapeutic agent at a given temperature (Geytenbeek, 2002).

Types of Physical Exercise Training for COPD Patients 363

Physical therapy for COPD requires a certain duration and frequency in order to improve clinical parameters. Wadell et al. (2005a) indicated that training once a week (high intensity/low frequency) was not sufficient to sustain the improvements in physical capacity and quality of life achieved after a period of 3 months of high frequency aquatic exercise training with three sessions of 45 minutes each a week (high intensity/high frequency). However, high intensity physical training once a week for 6 months seemed to be enough to avoid deterioration compared to baseline. According to Kurabayashi's study, 6 consecutive days of exercise a week would be preferable to 3 alternative days of exercise a week, even if the cumulative exercise period was the same (Kurabayashi et al., 1998). The studies reviewed showed much heterogeneity with respect to the duration of treatment, ranging from 6 to 24 weeks. However, the typical duration of treatment was 8 to 12 weeks. Further studies should direct more attention to the specific duration, frequency and accuracy of aerobic intensity thresholds. Other authors found that exercise in water tends to provide even greater benefits than similar exercise training on land (Wadell, Sundelin,

Breathing exercises during immersion in water at 38 ºC could be recommended as physical therapy after diagnosis of COPD. Elevation of the sub-peritoneal diaphragmatic pressure by the hydraulic pressure could help raise the diaphragm and assist in the evacuation of air during exhalation, resulting in a decrease in dead space. In addition, hydraulic pressure was reported to increase cardiac output, resulting in an improvement in blood gas exchange in lung capillaries. Besides these effects, inhalation of gas containing thermal hydrogen sulfate lowers the viscosity of sputum (Asanuma, Fujita, Ide, & Agishi, 1971). Only three studies (Kurabayashi et al., 2000; Kurabayashi et al., 1998; Perk, Perk, & Bodén, 1996) included breathing exercises during therapeutic aquatic

In general, patients with COPD have weak inspiratory muscles (Polkey et al., 1996). This weakness may contribute to dyspnea and exercise limitation in patients with significant COPD. When evaluating the strength of respiratory muscles we should be aware that we are focusing primarily on the ability of these muscles to generate tension during a forced inspiratory or expiratory maneuver. The result of the maneuver can be measured with the mouth (Figure 6 Equipment to maneuver), and it is measured in centimeters H2O. This primarily reflects a set of variables such as muscle mass (ability to generate force) and

The role of inspiratory muscle training (IMT) for individuals with stable COPD is unclear (Geddes, O'Brien, Reid, Brooks, & Crowe, 2008). The first systematic review on IMT found little evidence to support the use of IMT (Shoemaker, Donker, & Lapoe, 2009). The Amercian Thoracic Society/European Respiratory Society standards (Celli, MacNee et al., 2004) nor the Canadian Thoracic Society Recommendations for the Management of COPD (O'Donnell et al., 2008) recommend the incorporation of IMT into management plan. The Global Initiative for Chronic Obstructive Lung Disease *(GOLD,* 2010) states that "respiratory muscle training is beneficial, especially when combined with general exercise training"

Henriksson-Larsen, & Lundgren, 2004).

exercise intervention.

**3.3 Respiratory muscle training** 

length-tension relationship.

based on non-randomized trials and observational studies.

There is controversy in the scientific literature regarding the beneficial and harmful effects of water exercise for the respiratory system in people with respiratory problems. Different types of exercises can be carried out: walking, cycling, lifting weights in a swimming pool (figure 5), and so on. Previous studies show that hydrostatic pressure exerts on inspiratory muscle strength and limited chest expansion; this effect is enhanced as the temperature of the pool water decreases (Frontera, Herring, Micheli, & Silver, 2008). In addition, the diaphragm moves during diving due to compression by the abdomen, thus decreasing respiratory vital capacity (Greenleaf, 1984). Patients with chronic obstructive pulmonary disease benefit from the hydrostatic pressure exerted during immersion, which facilitates expiration and reduces the residual volume, decreasing the air trapped in this pathology (Asanuma, 1999; Dahlback, 1975; Schoenhofer, Koehler, & Polkey, 2004). Previous studies show that water exerts hydrostatic pressure on inspiratory muscle strength and limited chest expansion, this effect is enhanced with decreasing the temperature of the pool water (Agostoni, Gurtner, Torri, & Rahn, 1966). Therapeutic aquatic exercise intervention is known for its ability to prevent and treat different conditions. This intervention is a specialized field of physical training and therapy, used to achieve certain physical and functional goals using the properties of water (Geytenbeek, 2008).

The reviewed articles covered incremental therapeutic aquatic exercise with an intensity ranging from 50% to 90% of maximal oxygen consumption (VO2max) with sessions of 30 to 50 minutes 2 to 5 days a week, for a total of 8 to 24 weeks at a temperature of 29 ºC to 38 ºC (Kurabayashi et al., 2000; Wadell, Sundelin, Henriksson-Larsen, Lundgren, 2004). COPD patients walked in water to the level of their shoulders, and they breathed out slowly through their mouth into water after sinking their nose 3-5 cm below the water level. The patients` eyes were not under the water. After exercise, patients dressed and rested on a chair in a comfortable room (25ºC) for 30 minutes. Two studies showed clinical changes in the questionnaire of quality of life for respiratory patients. People who performed incremental exercise in the water showed functional changes in the distance walked in the walking test, in forced vital capacity and forced expiratory volume (Kurabayashi et al., 2000; Wadell, Sundelin, Henriksson-Larsen, & Lundgren, 2004). The aquatic intervention group that performed incremental exercise had improved health-related quality of life, compared to a control group without intervention (Wadell, Sundelin, Henriksson-Larsen, & Lundgren, 2004).

Fig. 5. Cycling and lifting weights

There is controversy in the scientific literature regarding the beneficial and harmful effects of water exercise for the respiratory system in people with respiratory problems. Different types of exercises can be carried out: walking, cycling, lifting weights in a swimming pool (figure 5), and so on. Previous studies show that hydrostatic pressure exerts on inspiratory muscle strength and limited chest expansion; this effect is enhanced as the temperature of the pool water decreases (Frontera, Herring, Micheli, & Silver, 2008). In addition, the diaphragm moves during diving due to compression by the abdomen, thus decreasing respiratory vital capacity (Greenleaf, 1984). Patients with chronic obstructive pulmonary disease benefit from the hydrostatic pressure exerted during immersion, which facilitates expiration and reduces the residual volume, decreasing the air trapped in this pathology (Asanuma, 1999; Dahlback, 1975; Schoenhofer, Koehler, & Polkey, 2004). Previous studies show that water exerts hydrostatic pressure on inspiratory muscle strength and limited chest expansion, this effect is enhanced with decreasing the temperature of the pool water (Agostoni, Gurtner, Torri, & Rahn, 1966). Therapeutic aquatic exercise intervention is known for its ability to prevent and treat different conditions. This intervention is a specialized field of physical training and therapy, used to achieve certain physical and functional goals using

The reviewed articles covered incremental therapeutic aquatic exercise with an intensity ranging from 50% to 90% of maximal oxygen consumption (VO2max) with sessions of 30 to 50 minutes 2 to 5 days a week, for a total of 8 to 24 weeks at a temperature of 29 ºC to 38 ºC (Kurabayashi et al., 2000; Wadell, Sundelin, Henriksson-Larsen, Lundgren, 2004). COPD patients walked in water to the level of their shoulders, and they breathed out slowly through their mouth into water after sinking their nose 3-5 cm below the water level. The patients` eyes were not under the water. After exercise, patients dressed and rested on a chair in a comfortable room (25ºC) for 30 minutes. Two studies showed clinical changes in the questionnaire of quality of life for respiratory patients. People who performed incremental exercise in the water showed functional changes in the distance walked in the walking test, in forced vital capacity and forced expiratory volume (Kurabayashi et al., 2000; Wadell, Sundelin, Henriksson-Larsen, & Lundgren, 2004). The aquatic intervention group that performed incremental exercise had improved health-related quality of life, compared to a control group without intervention (Wadell, Sundelin, Henriksson-Larsen, & Lundgren,

the properties of water (Geytenbeek, 2008).

Fig. 5. Cycling and lifting weights

2004).

Physical therapy for COPD requires a certain duration and frequency in order to improve clinical parameters. Wadell et al. (2005a) indicated that training once a week (high intensity/low frequency) was not sufficient to sustain the improvements in physical capacity and quality of life achieved after a period of 3 months of high frequency aquatic exercise training with three sessions of 45 minutes each a week (high intensity/high frequency). However, high intensity physical training once a week for 6 months seemed to be enough to avoid deterioration compared to baseline. According to Kurabayashi's study, 6 consecutive days of exercise a week would be preferable to 3 alternative days of exercise a week, even if the cumulative exercise period was the same (Kurabayashi et al., 1998). The studies reviewed showed much heterogeneity with respect to the duration of treatment, ranging from 6 to 24 weeks. However, the typical duration of treatment was 8 to 12 weeks. Further studies should direct more attention to the specific duration, frequency and accuracy of aerobic intensity thresholds. Other authors found that exercise in water tends to provide even greater benefits than similar exercise training on land (Wadell, Sundelin, Henriksson-Larsen, & Lundgren, 2004).

Breathing exercises during immersion in water at 38 ºC could be recommended as physical therapy after diagnosis of COPD. Elevation of the sub-peritoneal diaphragmatic pressure by the hydraulic pressure could help raise the diaphragm and assist in the evacuation of air during exhalation, resulting in a decrease in dead space. In addition, hydraulic pressure was reported to increase cardiac output, resulting in an improvement in blood gas exchange in lung capillaries. Besides these effects, inhalation of gas containing thermal hydrogen sulfate lowers the viscosity of sputum (Asanuma, Fujita, Ide, & Agishi, 1971). Only three studies (Kurabayashi et al., 2000; Kurabayashi et al., 1998; Perk, Perk, & Bodén, 1996) included breathing exercises during therapeutic aquatic exercise intervention.

#### **3.3 Respiratory muscle training**

In general, patients with COPD have weak inspiratory muscles (Polkey et al., 1996). This weakness may contribute to dyspnea and exercise limitation in patients with significant COPD. When evaluating the strength of respiratory muscles we should be aware that we are focusing primarily on the ability of these muscles to generate tension during a forced inspiratory or expiratory maneuver. The result of the maneuver can be measured with the mouth (Figure 6 Equipment to maneuver), and it is measured in centimeters H2O. This primarily reflects a set of variables such as muscle mass (ability to generate force) and length-tension relationship.

The role of inspiratory muscle training (IMT) for individuals with stable COPD is unclear (Geddes, O'Brien, Reid, Brooks, & Crowe, 2008). The first systematic review on IMT found little evidence to support the use of IMT (Shoemaker, Donker, & Lapoe, 2009). The Amercian Thoracic Society/European Respiratory Society standards (Celli, MacNee et al., 2004) nor the Canadian Thoracic Society Recommendations for the Management of COPD (O'Donnell et al., 2008) recommend the incorporation of IMT into management plan. The Global Initiative for Chronic Obstructive Lung Disease *(GOLD,* 2010) states that "respiratory muscle training is beneficial, especially when combined with general exercise training" based on non-randomized trials and observational studies.

Types of Physical Exercise Training for COPD Patients 365

as 5 weeks, IMT should become part of the individual´s exercise program. The minimal training intensity necessary could start as low as 22% PImax and be progressed to as high as 60% PImax using a targeted inspiratory resistive or threshold trainer (Geddes et al., 2005). Therefore, IMT significantly increased inspiratory muscle strength and inspiratory muscle endurance (Lotters, van Tol, Kwakkel, & Gosselink, 2002). In addition, research review found a clinically significant decrease in dyspnea sensation at rest and during exercise is

In conclusion, IMT improves inspiratory muscle strength and endurance, functional exercise capacity, dyspnea and quality of life. Inspiratory muscle endurance training was shown to be less effective than respiratory muscle strength training. In patients with inspiratory muscle weakness, the addition of IMT to a general exercise training program improved

Furthermore, maximal inspiratory pressure is a volitional test and therefore open to criticism (Polkey & Moxham, 2004). Futher research is needed to explore the impact that different training protocols (frequency, intensity and duration of IMT, supervision) may have on outcomes and to determine the extent to which changes in outcomes associated with IMT translate into clinically important improvement for adults with COPD (Geddes et al., 2008).

In the research reviewed, there are strong arguments that pulmonary rehabilitation is beneficial for improving the quality of life related to health at the beginning of the program. Furthermore pulmonary rehabilitation reduces symptoms and increases participation in everyday activities. However, it is necessary to do more randomized controlled trials to clarify which components of the lung rehabilitation are essential. Future studies to discover the ideal length of treatment, the necessary degree of supervision, training intensity and

Without no doubt, it is necessary to individualize programs for this population taking into account their different levels of severity. The prescription should begin at low intensity and

In summary, incremental aerobic resistance physical exercises are better than constant load physical exercises at an intensity range from 90% to 50 % of VO2 max, with a frequency of two or four days a week, the session is from 30 to 60 minutes during a period of treatment from eight to twelve weeks. Exercise training induces several symptomatic and functional adaptations resulting in an increased aerobic capacity, although clinical relevance is not collected in the study population. Maybe, for further studies we should take intrinsic patient factor (severity of COPD) into account over a longer period of time and how extrinsic factors of the exercises affect disease progression. Moreover, it is important to determine whether these physiological benefits of COPD patients who have performed an incremental aerobic resistance physical exercises program supervised justify the increased costs. Therefore, a cost/effectiveness analysis is necessary to determining whether the type of intervention

It is essential to investigate physical activity in daily life in patients with COPD in accordance to the GOLD stages. Pulmonary rehabilitation programs should incorporate the

short duration, for both parameters gradually increasing to the threshold of fatigue.

PImax and tended to improve exercise performance (Gosselink et al., 2011).

observed after IMT (Lotters et al., 2002).

how long the treatment effect persists.

program is supervised or not.

**4. Implications** 

Fig. 6. Equipment to maneuver

In an attempt to reduce the severity of breathlessness and to improve exercise tolerance, IMT has been applied in many COPD patients (Weiner, Magadle, Beckerman, Weiner, & Berar-Yanay, 2003). Several different respiratory muscle training devices are available, ranging from sophisticated computerized systems to simple hand-held resistive devices. In addition, the relative benefits of strength versus endurance training, inspiratory versus expiratory training and effect in patients of differing severity are unknown (Garrod & Lasserson, 2007)

#### *Types of intervention: Sham, low- and high-intensity IMT*

There are studies comparing the effect of different types of intervention (Geddes, Reid, Crowe, O'Brien, & Brooks, 2005). In order to standardize studies that showed sham IMT and low intensity IMT at similar percentages of maximum inspiratory pression (PImax). Bégin et al., (Begin & Grassino, 1991) measured these loads using the tidal inspiratory pressure (PI) of individuals with COPD. Sham IMT was defined as that using the same type of device as the intervention group at an intensity less than or equal to the mean plus one standard deviation (SD). Since PI is directly proportional to the partial pressure of carbon dioxide in the arterial blood (PCO2) of patients with COPD (Begin & Grassino, 1991), sham IMT for normocapneic individuals was defined as intensity p8.3 cm H2O (mean PI +1 SD) and for individuals with moderate hypercapnia, as intensity p11.5 cm H2O (Geddes et al., 2005).

Using IMT in combination with other interventions and using flow-dependent resistive training is important in the pulmonary rehabilitation program (Geddes et al., 2008). However, there are no established thresholds for what constitutes a clinically meaningful change in inspiratory muscle strength or endurance, other methods must be utilized to infer clinical benefit (Shoemaker et al., 2009). Geddes et al. (2005) recommended using IMT at least a total of 30 minutes daily but can be spread over more than one session a day. Training should occur at least 5 days a week. While gains may be measurable after as short as 5 weeks, IMT should become part of the individual´s exercise program. The minimal training intensity necessary could start as low as 22% PImax and be progressed to as high as 60% PImax using a targeted inspiratory resistive or threshold trainer (Geddes et al., 2005). Therefore, IMT significantly increased inspiratory muscle strength and inspiratory muscle endurance (Lotters, van Tol, Kwakkel, & Gosselink, 2002). In addition, research review found a clinically significant decrease in dyspnea sensation at rest and during exercise is observed after IMT (Lotters et al., 2002).

In conclusion, IMT improves inspiratory muscle strength and endurance, functional exercise capacity, dyspnea and quality of life. Inspiratory muscle endurance training was shown to be less effective than respiratory muscle strength training. In patients with inspiratory muscle weakness, the addition of IMT to a general exercise training program improved PImax and tended to improve exercise performance (Gosselink et al., 2011).

Furthermore, maximal inspiratory pressure is a volitional test and therefore open to criticism (Polkey & Moxham, 2004). Futher research is needed to explore the impact that different training protocols (frequency, intensity and duration of IMT, supervision) may have on outcomes and to determine the extent to which changes in outcomes associated with IMT translate into clinically important improvement for adults with COPD (Geddes et al., 2008).
