O6.2 Exercise training

Exercise is defined as physical activity that is planned, structured and repetitive, and undertaken with the aim of improving or maintaining physical fitness and for health benefits (Garber 2011). Exercise training (whole body endurance training and strength training) is considered to be the essential component of pulmonary rehabilitation (Alison 2017, Spruit 2013, Ries 2007). Numerous RCTs in people with moderate to severe COPD have shown decreased symptoms (dyspnoea and fatigue), increased maximal and functional exer­cise capacity and improved Health-related Quality of Life (HRQoL), emotional function and the individuals’ self-control over their condition following exercise training alone (Alison 2017, McCarthy 2015, Spruit 2013, Ries 2007, Paneroni 2020) [evidence level I]. Improvements in muscle strength and self-efficacy have also been reported (Ries 2007, Bolton 2013) [evidence level II]. Exercise training may confer a significant but small increase in physical activity (Mantoani 2016) [evidence level I].

Recommendations for exercise training in people with COPD are based on those recommendations for healthy adults (Garber 2011, Spruit 2013). However, since many individuals with COPD are unlikely to be able to achieve the recommendation for moderate to vigorous intensity exercise involving large muscle groups sustained for prolonged periods (i.e. 20-60 minutes) (Garber 2011) some modifications to these recommendations are required. Specifically, for people with COPD to accumulate the recommended dose (≥ 150 minutes per week of moderate intensity exercise, involving large muscle groups and accumulated over ≥ 5 days) they frequently need to undertake periods of exercise interspersed with rest periods in order to manage their dyspnoea. It is important to reassure patients that breathlessness on activity is not harmful and a degree of breathlessness is necessary in order to gain the benefits of exercise. When commencing an exercise program most individuals will need to gradually build up to the recommended weekly dose of exercise. Walking (ground-based or treadmill) and or stationary cycling are the forms of endurance exercise most commonly employed in exercise training programs for people with COPD (Spruit 2013) with ground-based walking having the advantage that it requires no equipment and can translate into improvements in walking capacity (Wootton 2014).  Strength training is also recommended on at least 2 days each week interspersed with at least one rest day (Garber 2011). A systematic review and meta-analysis (de Lima 2020) including 3 studies and 145 participants suggests elastic resistance training may be an alternative to conventional resistance training using weight machines for improving knee extensor muscle strength due to similar effects [evidence level I]. In order to gain the most benefit from an exercise program it is likely that many individuals with COPD will require supervision from a health professional who has a knowledge of lung pathology and exercise prescription for people with chronic lung disease.

There is evidence from a multicentre, RCT (n=143) carried out in Australia that provides some support for the use of supervised ground based walking training as the sole modality of exercise training in people with moderate to severe COPD (Wootton 2014). This trial demonstrated significant benefits in HRQoL and endurance walking capacity favouring the walking training group [evidence level II] however some of the benefits were of a lesser magnitude than reported following a comprehensive pulmonary rehabilitation program. Supervised walking training in isolation has a therapeutic role where access to pulmonary rehabilitation programs is limited or when specialised exercise equipment is unavailable.

In an Australian study of telerehabilitation comparing 8 weeks of group exercise training thrice weekly, compared to usual medical management involving pharmacotherapy and an action plan, the endurance shuttle walk test improved significantly in the trained group compared with usual care: 340 seconds (95% CO 153-526, p<0.001) (MCID 180 seconds). However, there were no significant differences in quality of life or physical activity measured as steps walked per day between the two groups (Tsai 2017) [evidence level II], despite the control group not receiving an exercise intervention.

Most of the evidence for the benefits from exercise training has been gained from supervised programs that involved land-based exercise training, however a Cochrane Review provides limited evidence from RCTs conducted in a small number of patients with COPD that water-based exercise may confer short-term benefits in exercise capacity and quality of life (McNamara 2013b) [evidence level I].  The Australian study included in this Cochrane Review specifically recruited individuals with COPD who had concurrent physical comorbidities such as obesity or significant musculoskeletal problems that limited the ability to participate in a land-based exercise program (McNamara 2013a). Thus, supervised water-based exercise training may provide an alternative for people with COPD whose comorbidities preclude land-based exercise training or when pulmonary rehabilitation programs are unavailable.

Unsupervised exercise training using a formal prescription of frequency, intensity, time and type can significantly improve disease-specific quality of life in people with COPD, but not exercise capacity (Taylor 2021) [evidence level I]. Supervised exercise training is required to improve exercise capacity.