Meta- analysis revealed few clinical ly relevant and statistically significant benefits of " add-on " therapies on exercise performance compared with exercise training .
The aim of this review was to identify the effectiveness of therapies added on to conventional exercise training to maximise exercise capacity in patients with chronic obstructive pulmonary disease ( COPD ) .
Polyunsaturated fatty acids improve exercise capacity in chronic obstructive pulmonary disease.
BACKGROUND Muscle wasting and decreased muscle oxidative capacity commonly occur in patients with chronic obstructive pulmonary disease ( COPD ) .  Polyunsaturated fatty acids ( PUFA ) have been shown to mediate several inflammatory and metabolic pathways which may be involved in the pathogenesis of muscle impairment in COPD . The aim of this study was to investigate the effect of PUFA modulation on systemic inflammation , reversal of muscle wasting , and functional status in COPD . METHODS Eighty patients with COPD ( 57 men ) with forced expiratory volume in 1 second ( FEV1 ) 37.3 (13.8)% predicted received 9 g PUFA or placebo daily in a double blind r and omised fashion during an 8 week rehabilitation programme . Body composition ( bioelectrical impedance ) , functional capacity ( lung function , incremental cycle ergometry test , submaximal cycle test , isokinetic quadriceps strength ) and inflammatory markers ( C-reactive protein ( CRP ) , interleukin (IL)-6 and tumour necrosis factor (TNF)-alpha ) were assessed at baseline and after 8 weeks . RESULTS Both groups had similar increases in weight , fat-free mass ( FFM ) , and muscle strength . The peak load of the incremental exercise test increased more in the PUFA group than in the placebo group ( difference in increase 9.7 W ( 95 % CI 2.5 to 17.0 ) , p = 0.009 ) even after adjustment for FFM . The duration of the constant work rate test also increased more in patients receiving PUFA ( difference in increase 4.3 min ( 95 % CI 0.6 to 7.9 ) , p = 0.023 ) . The positive effects of PUFA could not be attributed to a decrease in systemic levels of CRP , IL-6 and TNF-alpha . CONCLUSIONS This is the first study to show beneficial effects of PUFA on exercise capacity in patients with COPD
Meta- analysis revealed few clinical ly relevant and statistically significant benefits of " add-on " therapies on exercise performance compared with exercise training .
The aim of this review was to identify the effectiveness of therapies added on to conventional exercise training to maximise exercise capacity in patients with chronic obstructive pulmonary disease ( COPD ) .