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A significant percentage of patients with end-stage renal disease are malnourished and/or muscle wasted. Uremia is associated with decreased protein synthesis and increased protein degradation. Fortunately, nutritional status has been shown to be a modifiable risk factor in the dialysis population. It has long been proposed that exercise could positively alter the protein synthesis-degradation balance. Resistance training had been considered as the only form of exercise likely to induce anabolism in renal failure patients. However, a small, but growing, body of evidence indicates that for some dialysis patients, favourable improvements in muscle atrophy and fibre hypertrophy can be achieved via predominantly aerobic exercise training. Moreover, some studies tentatively suggest that nutritional status, as measured by SGA, can also be modestly improved by modes and patterns of exercise training that have been shown to also increase muscle fibre cross-sectional area and improve functional capacity. Functional capacity tests can augment the information content of basic nutritional status assessments of dialysis patients and as such are recommended for routine inclusion as a feature of all nutritional status assessments.

Objective: To determine the interday reproducibility of peak and submaximal exercise tolerance of patients with end-stage renal disease (ESRD)., Design: Repeated measures., Setting: Day-patient rehabilitation center., Participants: Twelve consecutively presenting, self-selected patients with ESRD., Interventions: All patients performed peak exercise tolerance assessments on a cycle ergometer up to the point of volitional fatigue, with a 1-week interval between the 2 tests., Main Outcome Measures: Cardiopulmonary, hemodynamic, and physical performance parameters were assessed at peak exercise and at the lactate threshold. Standard error of measurement, percentage coefficient of variation (CV%), intraclass correlation coefficient (ICC), and limits of agreement (LOA) were calculated to determine the reproducibility of all variables., Results: CV% (range, 5%-7%) and ICCs (range, .94 - .98) for oxygen uptake and heart rate at peak exercise and lactate threshold indicated highly acceptable levels of group mean reproducibility. LOA analysis revealed satisfactory levels of reproducibility for individual patients., Conclusion: Taken together, these reproducibility data may be applied to clinical work, requiring the quantification of changes in the exercise tolerance of patients with ESRD after short-term interventions (eg, exercise training, therapeutic use of recombinant erythropoietin)., (Copyright 2001 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation)

This study investigated the reproducibility of blood lactate-anchored ratings of perceived exertion (RPE) in seven women of average, and seven of above average cardiorespiratory fitness, [moderate and high maximal oxygen uptake (Mod VO2max and High VO2max, respectively)]. The subjects completed a series of four exercise tests, comprising a VO2max assessment and three O-grade, velocity-incremental, treadmill-running RPE estimation trials. The results revealed no significant between-group differences in RPE at the blood lactate concentration threshold (LT), and at reference levels of 2, 2.5 or 4 mmol x l(-1) (RPELT, RPE2, RPE2.5 and RPE4, respectively). The RPELT, RPE2, RPE2.5 and RPE4 were characterised by intra-class correlation coefficients of 0.97, 0.97, 0.97, 0.72 and 0.83, 0.96, 0.96, 0.90, in the High VO2max and Mod VO2max groups, respectively. The SEM% (95% confidence limits computed as a percentage of the group mean score) largely mirrored the trend in reliability with the highest values observed for RPELT in the Mod VO2max group and RPE4 in the High VO2max group. The Spearman-Brown prediction equation indicated that fixed blood lactate concentrations of 2, 2.5 and 4 mmol x l(-1) offer acceptable practical utility as potential perceptual anchor points for both groups, requiring one trial only to achieve a measurement error of less than +/- 6%.

Purpose: The purpose of this study was to investigate the effect of endurance activities designed to simulate the physiological demands of soccer match-play and training, on leg strength, electromechanical delay, and knee laxity., Methods: Eight recreational soccer players completed four exercise trials in random order: 1) a prolonged intermittent high intensity shuttle run (PHISR) which required subjects to complete a total distance of 9600 m in a form simulating the pattern of physical activity in soccer match-play (activity mode; rest-to-work intervals; approximately 90 min duration), 2) a shuttle-run (SR), (3) a treadmill run (TR) which required subjects to complete an equivalent distance at a running speed corresponding to 70% VO2max, and 4) a control condition consisting of no exercise., Results: Results from repeated measures ANOVA revealed significant condition (PHISR; SR; TR; control) by time (pre; mid; post) interactions for peak torque (PT: knee extension and flexion: 1.05 rad.s-1), EMD and anterior tibio-femoral displacement (TFD) (P < 0.05). Impairment to indices of knee joint performance was observed in PHISR, SR, and TR trials. The greatest decrement occurred in PHISR and SR trials (up to 44%). Knee extensor and flexor strength performance near to full knee extension (0.44 rad knee flexion) was not changed following the functionally-relevant endurance activities., Conclusions: Even though strength performance near to full knee extension was preserved following acute endurance activities, the risk of ligamentous injury may be increased by concomitant impairment to EMD and anterior TFD.