Background: Interstitial lung disease (ILD) is characterised by reduced functional capacity, dyspnoea and exercise-induced hypoxia. Physical training is beneficial for people with other chronic lung conditions, however its effects in ILD have not been well characterised. Objectives: To assess the effects of physical training on exercise capacity, symptoms, quality of life and survival compared to no physical training in people with ILD. Search strategy: We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library 2007, Issue 4), MEDLINE, EMBASE, CINAHL and the Physiotherapy Evidence Database (PEDro) (all searched from inception to December 2007). The reference lists of relevant studies were hand-searched for qualifying studies. Selection criteria: Randomised or quasi-randomised controlled trials in which physical training was compared to no physical training or to other therapy in people with ILD of any aetiology were included. Data collection and analysis: Two review authors independently selected trials for inclusion, extracted data and assessed risk of bias. Authors were contacted to obtain missing data and information regarding adverse effects. A priori subgroup analyses were specified for participants with idiopathic pulmonary fibrosis (IPF), severe lung disease and training modality. Main results: Five studies were included, three of which were published as abstracts. Two studies were included in the meta-analysis (43 participants who undertook physical training and 42 control participants). One study used a blinded assessor and intention-to-treat analysis. No adverse effects of physical training were reported. Physical training improved the 6-minute walk distance with weighted mean difference (WMD) 38.61 metres (95% confidence interval 15.37 to 61.85 metres). Improvement in 6-minute walk distance was also seen in the subgroup of participants with IPF (WMD 26.55 metres, 2.81 to 50.30 metres). No effect of physical training on VO 2peak was evident. There was a reduction in dyspnoea (standardised mean difference (SMD) -0.47, 95% CI: -0.91 to -0.04) however this did not reach significance in the IPF subgroup (SMD -0.43, 95% CI: -0.94 to 0.08). Quality of life improved following physical training in all participants (SMD 0.58, 95% CI: 0.15 to 1.02) and in IPF (SMD 0.57, 95% CI: 0.06 to 1.09). Only one study reported longer-term outcomes, with no significant effects of physical training on clinical variables or survival at six months. Insufficient data were available to examine the impact of disease severity or training modality. Authors' conclusions: Physical training is safe for people with ILD. Improvements in functional exercise capacity, dyspnoea and quality of life are seen immediately following training, with benefits also evident in IPF. There is little evidence regarding longer-term effects of physical training.