systemic sclerosis is a multisystem disease with pulmonary involvement , which decreases exercise capacity and is related to survival.1,2 medication and exercise training have recently been shown to improve dyspnea , six - minute walking distance , maximum heart rate , and quality of life.3 most training studies4,5 have been performed using 8-week programs based on pulmonary rehabilitation used in the treatment of chronic obstructive pulmonary disease.6,7 this study was performed to evaluate the effects of a rehabilitation program including walking training over a 6-month period in a patient with systemic sclerosis and to determine any improvement in exercise capacity . a 43-year - old male patient with systemic sclerosis and ild was admitted with chronic ulceration of his fingers . he had been treated for 4 years with corticosteroids , and at a dose of 10 mg for the 4 months prior to presentation . his hugh - jones grade was 3 , ie , he was unable to keep up with healthy persons walking on the level , but was able to walk for one mile ( 1.6 km ) or more at a slower speed . on admission , forced vital capacity was 61.5% and carbon monoxide diffusion capacity ( dlco ) was 29.8% of predicted . right ventricular systolic pressure was 39 mmhg and mean pulmonary artery pressure was 18 mmhg . his six - minute walking distance was 521 m , with oxygen saturation ( spo2 ) declining from 96% at rest to 72% at completion , determined using a handheld pulse oximeter with a reflectance sensor on the forehead . perceived exertion increased from 0 to 4 on the borg 10 scale . walking distance without rest was 60 m when spo2 declined to 85% . after admission to hospital , the corticosteroid dose was kept the same as before , but bosentan , sildenafil , and prostacyclin derivatives were added to treat the ulcers . the prostacyclin dose was increased during the first 8 weeks of admission , and then remained unchanged until discharge . the rehabilitation program included walking training , training for leg muscle strengthening with a sand weight of 2.5 kg on the mat , and additional stretching exercise for the fingers because of sclerotic skin changes . the total time spent exercising was about one hour per day on 5 days per week . the patient gave informed consent to these rehabilitation treatments before starting the program . on the first day of walking training , 60 m walking in one minute was performed based on the first evaluation and was repeated with rest intervals of a few minutes . figure 1 shows the training walking distance starting from 60 m , increasing gradually to 300 m after 27 weeks of training . the six - minute walking distance , evaluated five times , was about 500 m , and perceived exertion in the fifth test also increased from 0 to 4 on the borg scale , while the end value of spo2 was increased . at discharge , when the finger ulcers had resolved , forced vital capacity was 59.8% and dlco was 24.2% of predicted . right ventricular systolic pressure was 36 mmhg and mean pulmonary artery pressure was 19 mmhg , suggesting little change in cardiopulmonary function . this patient showed no improvement in six - minute walking distance . in copd patients , the minimal important difference for a six - minute walking distance test is 25 m,8 and was 22 m in this patient . one of the exclusion criteria for the six - minute walking test is an initial resting spo2 < 90%.9 however , there are no clear criteria to discontinue the test in relation to low spo2 . the final spo2 in this patient was 72%80% , showing slight improvement , although these values were thought to be harmful to his circulation . because this patient had no severe dyspnea during the six - minute walking test , it was recommended that he continue most of his daily activities despite the low oxygen saturation which might have been causing his finger ulcers . during training in ild , high - intensity interval exercise training for copd is effective in inducing peripheral muscle adaptation , with less dyspnea compared with constant - load exercise.11 these studies are encouraging with regard to interval walking training ( spo2 > 90% ) for ild patients . exercise training was beneficial to our patient in reducing the risk of hypoxia during walking up to 300 m. thus , exercise training would be effective in improving safety , considering both hemodynamics and skin ulcer recurrence . bosentan is reported to have no effect on the six - minute walking distance in idiopathic pulmonary fibrosis,12 whereas prostacyclin derivatives improved six - minute walking distance test in systemic sclerosis with pulmonary arterial hypertension.12 these medications for pulmonary arterial hypertension did not improve cardiopulmonary function nor exercise capacity in our patient . generally , exercise training for lung disease is known to increase exercise capacity over 8 weeks . although the six - minute walking distance in this patient was about 500 m and did not change after exercise training , the risk of hypoxia was remarkably reduced up to 300 m of walking . this case report suggests a benefit of exercise training to ameliorate hypoxia in addition to improving exercise capacity .
pulmonary rehabilitation is effective for improving exercise capacity in patients with interstitial lung disease ( ild ) , and most programs last about 8 weeks . 
 a 43-year - old male patient with systemic sclerosis and oxygen saturation ( spo2 ) declining because of severe ild was hospitalized for treatment of chronic skin ulcers . during admission 
 , he completed a 27-week walking exercise program with spo2 monitoring . 
 consequently , continuous walking distance without severe hypoxia ( spo2 > 90% ) increased from 60 m to 300 m after the program , although his six - minute walking distance remained the same . 
 this suggests that walking exercise for several months may reduce the risk of hypoxia in patients with ild , even though exercise capacity does not improve .