Home-based exercise increased exercise capacity safely but did not improve quality of life in patients with chronic heart failure .
It could therefore be used to improve the management of people with chronic heart failure who do not have access to hospital-based exercise
QUESTIONS Does home-based exercise improve exercise capacity and quality of life in people with chronic heart failure ?
Is it safe ?
The effect of physical training on skeletal muscle in patients with chronic heart failure.
BACKGROUND The improvement of exercise capacity in patients with chronic heart failure ( CHF ) by physical training has been connected with reversal of the abnormalities in muscle fiber distribution and with the reduced activity of the enzymes of oxidative metabolism in skeletal muscle . However , the change in fiber type distribution induced by training is controversial and in previous studies the activities of the rate-limiting enzymes of the metabolic pathways have not been measured . AIMS To examine the effect of dynamic training on percentage distribution of muscle fibers , on activities of the rate-limiting enzymes of the metabolic pathways and on electrophysiology in skeletal muscle . METHODS A total of 27 patients with stable CHF ( NYHA class II-III ) were r and omized to a training ( N=12 ) or a control ( N=15 ) group . The training group exercised on a bicycle ergometer for 30 min three times a week for 3 months using a load corresponding to 50 - 60 % of their peak oxygen consumption . This was followed by a 3-month training period at home according to personal instructions . The control group did not change its physical activities . We studied muscle histology and measured the activities of the rate-limiting enzymes of anaerobic glycolysis ( phosphofructokinase , PFK ) , glycogenolysis ( phosphorylase ) , citric acid cycle ( alpha-ketoglurate dehydrogenase , KGDH ) and fatty acid oxidation ( carnitinepalmitoyl transferase I and II , CPT I and II ) from biopsies of the vastus lateralis muscle at baseline and after 3 and 6 months . Muscle strength and strength endurance with surface EMG and macro EMG of the right knee extensors were also determined . RESULTS Exercise capacity , particularly submaximal , improved in the training group . The activity of PFK rose significantly but that of the other enzymes did not when compared with the change in the controls . Training had no effect on the percentage distribution of slow-twitch and fast-twitch muscle fibers or on capillary density around these fibers in skeletal muscle . Maximum voluntary force , strength endurance and the function of motor units remained unaffected . CONCLUSIONS Dynamic training results in improved exercise endurance in CHF . In skeletal muscle , the capacity of anaerobic glycolysis is increased but that of the citric acid cycle and fatty acid oxidation is not . Furthermore , the improvement in exercise endurance seems to be independent of changes in the percentage distribution of muscle fibers , capillarity or electrophysiological factors
Home-based exercise increased exercise capacity safely but did not improve quality of life in patients with chronic heart failure .
It could therefore be used to improve the management of people with chronic heart failure who do not have access to hospital-based exercise
QUESTIONS Does home-based exercise improve exercise capacity and quality of life in people with chronic heart failure ?
Is it safe ?