Introduction 2003 2006 1999 2003 1999 2003 2002 1997 1993 2006 1999 1997 1993 2006a 2002 2006a 2006b 1999 2001 2001 2001 1999 2001 It may be hypothesized that deficits in physical fitness in liver transplant recipients are associated with complaints of fatigue. Furthermore, deficits in physical fitness may lead to impaired health-related quality of life (HRQoL). However, to our knowledge, no studies are available on the relationships between these parameters in liver transplant recipients. Because of the scarcity of studies on physical fitness and related parameters in liver transplant recipients, the present study assessed physical fitness (cardiorespiratory fitness, neuromuscular fitness, and body composition) in liver transplant recipients and explored whether physical fitness is related to severity of fatigue in this group. The relationship between physical fitness and HRQoL was also explored. Patients and methods Patients 2006a 1989 2006a 1 Table 1 n Age (years) 48.0 ± 11.8 Gender  Male 11  Female 7 n  a  Chronic 17  Acute 1 Time since transplantation (years) 3.3 ± 1.1 b  1 16  2 1  3 1 Results are presented as mean ± SD or numbers a n n n n b 1 2 3 Measurements Physical fitness: cardiorespiratory 2 1982 V 2peak −1 −1 −1 −1 FFM −1 −1 V 2peak V E V 2 2 V E V 2 2 1979 1999 1985 Physical fitness: neuromuscular ® Physical fitness: body composition ® −2 1974 Severity of fatigue 1989 1989 1999 2004 1982 1979 Health-related quality of life 1993 1992 Procedure On the day of the measurements, patients refrained from caffeine, nicotine, and heavy exercise. The order of the tests was standardized: patients started with the 6MWT, followed by the questionnaires (completed under supervision of the researcher), body composition measurements, strength test, and finally the progressive maximal aerobic test. Exercise tests were performed under supervision of a physician. There were sufficient rest periods between the tests. Statistics 2001 2001 1998 2001 1989 1995 1992 r s Results Physical fitness max max  1971 2 3 V 2peak  −1 −1  P P V 2peak FFM −1 −1  P P P 4 Table 2 Individual results on physical fitness in the 18 liver transplant recipients Age (year/Gender) −2 a b V 2peak  −1 −1 V 2peak  FFM −1 −1 b V 2peak  V 2peak  6MWD (m) PT extension 60°/s (Nm) PT extension 180°/s (Nm) 56/M 28.3 111.0 29.0 36.5 51.4 54.1 42.7 652 156.3 88.2 52/M 29.0  32.7 16.7 24.8 49.1 38.9 428 101.8 73.1 42/F 22.8  28.9 34.5 48.5 90.5 65.8 530 100.0 65.6 60/F 38.4 118.5 42.0 13.1 22.5 43.6 32.5 495 101.9 78.6 64/M 29.7 103.5 30.6 21.7 31.3 77.4 55.4 430 99.9 62.6 24/F 21.0 72.0 25.9 29.9 40.4 38.8 31.1 660 159.9 111.5 46/M 26.5 100.0 25.8 28.2 38.0 48.6 38.7 606 151.6 88.5 63/M 24.4  20.5 20.9 26.4 69.4 49.7 410 74.4 44.8 42/M 34.9 132.0  22.8  30.9 25.8 513 145.9 118.3 53/F 23.9 77.5 30.1 23.1 33.0 108.6 64.8 465 40.0 35.7 53/M 25.9 99.6 23.6 20.7 27.1 56.7 42.6 510 149.3 96.8 39/M 23.7 87.0 17.4 31.2 37.8 51.5 43.5 547 169.0 111.8 33/M 24.0 88.0 19.8 35.1 43.7 67.9 59.9 510 155.9 116.9 63/F 33.0 103.0 34.8 15.8 24.2 57.9 43.2 303 67.2 39.4 45/F 26.8  30.8 23.6 34.1 61.0 46.2 514 120.1 61.7 39/F 18.7 75.0 22.7 30.2 38.1 56.2 46.8 600 115.9 67.9 32/M 22.9 91.0 20.4 25.0 31.4 43.4 38.3 576 180.4 124.6 58/M 25.1 99.0 25.0 18.5 24.6 48.6 37.9 495 128.6 91.9   −2 V 2peak  −1 −1 V 2peak  FFM −1 −1 V 2peak V 2 a n b V 2peak n Table 3 Cardiorespiratory fitness and neuromuscular fitness in the liver transplant group  LTx group a P Cardiorespiratory fitness  V 2peak  −1 −1 24.8 ± 6.9 29.4 ± 7.4  (sed) †  37.5 ± 6.7  (recr) 0.00*  V 2peak  FFM −1 −1 b 34.0 ± 8.7 41.0 ± 7.8  (sed) 0.02*  50.9 ± 5.9 (recr) 0.00*  6MWD (m) 513.6 ± 88.9 609.6 ± 97.6  0.01* Neuromuscular fitness  PT extension at 60°/s (Nm) 123.2 ± 38.7 138.5 ± 44.1  0.22  PT extension at 180°/s (Nm)  82.1 ± 27.9 86.1 ± 30.1  0.59 Results are presented as mean ± SD V 2peak  −1 −1 V 2peak  FFM −1 −1 V 2peak V 2 6MWD a 2001 1998 2001 2001 b n P †  Table 4 Body composition in the liver transplant group Body composition Mean ± SD Body weight (kg) 80.6 ± 18.3 Height (m) 1.74 ± .11 −2 26.6 ± 5.0 a 96.6 ± 16.8 b 26.9 ± 6.4 Results are presented as mean ± SD a n b n Relationships 5 Table 5 Spearman correlation coefficients for the relationships between fitness parameters and severity of fatigue as measured with the Fatigue Severity Scale (FSS) and the Visual Analogue Scale (VAS) in 18 liver transplant recipients Physical fitness Fatigue FSS VAS Rs P Rs P Cardiorespiratory fitness  V 2peak  −1 −1 −0.40 0.10 −0.52 0.03*  % of sedentary norm −0.17 0.50 −0.42. †  % of recreational norm −0.32 0.20 −0.53 0.03* V 2peak  FFM −1 −1 a −0.43 † −0.51 0.04* a −0.35 0.17 −0.50 0.04* a −0.45 † −0.61 0.01* V 2peak  0.22 0.38 0.03 0.92 V 2peak  0.17 0.49 −0.06 0.82  6MWD (m) −0.44 † −0.53 0.03*  % of norm −0.25 0.32 −0.52 0.03* Neuromuscular fitness  PT extension at 60°/s (Nm) −0.39 0.11 −0.31 0.22  % of norm −0.15 0.56 −0.28 0.27  PT extension at 180°/s (Nm) −0.30 0.22 −0.12 0.64  % of norm 0.02 0.93 0.04 0.87 Body composition −2 0.03 0.91 0.06 0.82 b −0.07 0.82 −0.06 0.83 a 0.32 0.21 0.15 0.58 V 2 −1 −1 V 2 FFM −1 −1 V 2peak V 2 a n b n P †  V 2peak FFM −1 −1 V 2peak −1 −1 V 2peak FFM −1 −1 P V 2peak −1  −1  6 Table 6 Spearman correlations coefficients for the relationships between physical fitness and health-related quality of life as assessed with the RAND−36 in 18 liver transplant recipients Physical fitness RAND-36 domain PF SF Rlp Rle MH VT BP GH CH Cardiorespiratory fitness  V 2peak  −1 −1 0.55 – – – – – – – –  % of sedentary norm – 0.42 – – – 0.50 – – –  % of recreational norm 0.48 – – – – 0.51 – – –  V 2peak  FFM −1 −1 a 0.57 0.51 0.41 – – – – – – a – 0.56 – – – 0.59 – 0.48 – a 0.46 0.58 – – – 0.58 – – – V 2peak  – – – – – – – – – V 2peak  – – – – – – – – –  6MWD (m) 0.67 0.57 – – 0.53 – 0.54 – –  % of norm – 0.70 – – – 0.51 – – 0.44 Neuromuscular fitness  PT extension at 60°/s (Nm) 0.44 – – – .41 – – – –  % of norm – 0.68 – – – – 0.56 – –  PT extension at 180°/s (Nm) – – – – – – 0.44 – –  % of norm – 0.51 – 0.54 – – 0.50 – – Body composition −2 – – – – – – – – – b – – 0.49 –0.41 – – – – – a – –  – – – – –  P P V 2 −1 −1 V 2 FFM −1 −1 V 2peak V 2 a n b n Discussion This is the first study in which relationships between several aspects of physical fitness and severity of fatigue are explored after LTx. The study is an initial step in identifying factors that are associated with fatigue in liver transplant recipients. A limitation of this study may be that the sample was relatively small. However, we believe that this sample is representative for patients after LTx and that the study provides important information for the development of rehabilitation programs for liver transplant recipients. Physical fitness V 2peak V 2peak 1999 2001 2001 2003 1995 1996 2003 1998 1998 2001 1998 1995 2006b 1999 1999 2004 2001 V 2max V 2max  1997 1997 V 2peak Physical fitness and severity of fatigue 2006b In contrast to our expectations, the present study indicates that other aspects of physical fitness, neuromuscular fitness and body composition, do not seem to be related with severity of fatigue after LTx. However, it should be realized that our study sample was relatively small and some of the studied relationships may have failed to show statistical significance. Physical fitness and HRQoL 1998 2003 2001 2006b 2003 1998 2003 Our results on the relationships between physical fitness and HRQoL imply that rehabilitation programs aimed at improving physical fitness (particularly cardiorespiratory fitness) may consequently result in improved HRQoL, particularly in improved physical and social functioning, vitality, and bodily pain. However, these implications have to be confirmed in future randomized trials on the effects of such rehabilitation programs in liver transplant recipients. Conclusion Cardiorespiratory fitness in the liver transplant recipients was distinctly impaired and the prevalence of obesity was higher than in the general population; there were no indications that neuromuscular fitness is impaired after LTx. Based on the relationships we found between cardiorespiratory fitness and severity of fatigue, a rehabilitation program aimed at enhancing cardiorespiratory fitness may help in reducing complaints of fatigue after LTx. Such rehabilitation programs may also result in improved HRQoL.