Abstract: Two RCTs including a combined total of 40 participants (35 from one study and five from a second study) met the inclusion criteria. Twenty-one participants were randomised to the exercise training group and 19 participants were randomised to the control group. The included studies evaluated the effects of exercise training compared to a control group of no exercise training in people with dust-related ILDs and ARPD. The exercise training programme in both studies was in an outpatient setting for an eight-week period. The risk of bias was low in both studies. There were no reported adverse events of exercise training. Following exercise training, six-minute walk distance (6MWD) increased with a mean difference (MD) of 53.81 metres (m) (95% CI 34.36 to 73.26 m). Improvements were also seen in the domains of health-related quality of life: Chronic Respiratory Disease Questionnaire (CRQ) Dyspnoea domain (MD 2.58, 95% CI 0.72 to 4.44); CRQ Fatigue domain (MD 1.00, 95% CI 0.11 to 1.89); CRQ Emotional Function domain (MD 2.61, 95% CI 0.74 to 4.49); and CRQ Mastery domain (MD 1.51, 95% CI 0.29 to 2.72). Improvements in exercise capacity and health-related quality of life were also evident six months following the intervention period: 6MWD (MD 52.68 m, 95% CI 27.43 to 77.93 m); CRQ Dyspnoea domain (MD 3.03, 95% CI 1.41 to 4.66); CRQ Emotional Function domain (MD 5.57, 95% CI 2.34 to 8.81); and CRQ Mastery domain (MD 2.66, 95% CI 1.08 to 4.23). Exercise training did not result in improvements in the Modified Medical Research Council (MMRC) dyspnoea scale immediately following exercise training or six months following exercise training. The improvements following exercise training were similar in a subgroup of participants with dust-related ILDs and in a subgroup of participants with ARPD compared to the control group, with no statistically significant differences in treatment effects between the subgroups. The evidence examining exercise training in people with non-malignant dust-related respiratory diseases is of very low quality. This is due to imprecision in the results from the small number of trials and the small number of participants, the indirectness of evidence due to a paucity of information on disease severity and the data from one study being from a subgroup of participants, and inconsistency from high heterogeneity in some results. Therefore, although the review findings indicate that an exercise training programme is effective in improving exercise capacity and health-related quality of life in the short-term and at six months follow-up, we remain unsure of these findings due to the very low quality evidence. Larger, high quality trials are needed to determine the strength of these findings.

Plain-language summary: We included two studies with a total of 40 people (35 from one study and five from a second study). Of these people, 21 participated in exercise training and 19 did not participate in exercise training. All people were men and they were between 55 and 86 years old. Both exercise training programmes included cycling and walking and one programme also included strength training exercises. In both studies, training lasted for eight weeks with people attending two to three sessions per week. Immediately following exercise training, people walked an average of 53.81 metres further in a six-minute walk test than those who did not complete exercise training. Six months following exercise training, people walked 52.68 metres further in a six-minute walk test than those who did not complete exercise training. These improvements in exercise capacity were similar for people with dust-related interstitial lung disease and people with asbestos related pleural disease. Quality of life also improved more in people who exercised compared to those who did not. No one reported experiencing any unwanted effects due to exercise training. The quality of evidence was very low because there were only two studies and 40 people. Therefore, it is likely that these findings will change with more studies in the future. We need bigger studies that can confirm the findings of this Cochrane review.