Exercise for children with chronic kidney disease and end-stage renal disease.

It is well known that adults suffering from chronic kidney disease (CKD) experience muscle wasting and excessive fatigue, which results in a reduced exercise capacity and muscle weakness compared to their healthy counterparts, but research suggests that this can be improved through exercise. There is very limited data available regarding exercise tolerance in children with CKD and even less on the effects of exercise training programs. However, the available evidence does suggest that like adults, children also suffer from poor exercise capacity and reduced muscle strength, although the reasons for these limitations remain unclear. Studies that have attempted to implement exercise training programs in pediatric CKD populations have experienced high dropout rates, suggesting that the approach used to implement such programs in children needs to be different from the approach used for adults. This review summarizes the current knowledge regarding exercise capacity and muscle strength in children with CKD, the methods used to perform these assessments, and the possible causes of physical limitations. The results of exercise training studies, and the potential reasons as to why training programs have proved relatively unsuccessful are also discussed.

Benefits of regular walking exercise in advanced pre-dialysis chronic kidney disease.

BACKGROUND: There is increasing evidence of the benefit of regular physical exercise in a number of long-term conditions including chronic kidney disease (CKD). In CKD, this evidence has mostly come from studies in end stage patients receiving regular dialysis. There is little evidence in pre-dialysis patients with CKD Stages 4 and 5. METHODS: A prospective study compared the benefits of 6 months regular walking in 40 pre-dialysis patients with CKD Stages 4 and 5. Twenty of them were the exercising group and were compared to 20 patients who were continuing with usual physical activity. In addition, the 40 patients were randomized to receive additional oral sodium bicarbonate (target venous bicarbonate 29 mmol/L) or continue with previous sodium bicarbonate treatment (target 24 mmol/L). RESULTS: Improvements noted after 1 month were sustained to 6 months in the 18 of 20 who completed the exercise study. These included improvements in exercise tolerance (reduced exertion to achieve the same activity), weight loss, improved cardiovascular reactivity, avoiding an increase in blood pressure medication and improvements in quality of health and life and uraemic symptom scores assessed by questionnaire. Sodium bicarbonate supplementation did not produce any significant alterations. CONCLUSIONS: This study provides further support for the broad benefits of aerobic physical exercise in CKD. More studies are needed to understand the mechanisms of these benefits, to study whether resistance exercise will add to the benefit and to evaluate strategies to promote sustained lifestyle changes, that could ensure continued increase in habitual daily physical activity levels.

Exercise-induced biochemical modifications in muscle in chronic kidney disease: occult acidosis as a potential factor limiting the anabolic effect of exercise.

There is growing evidence that exercise may be beneficial in limiting or reversing problems related to chronic kidney disease (CKD); but exercise therapy has had limited success in increasing lean body mass, implying that metabolic abnormalities in muscle during CKD may limit the anabolic effectiveness of exercise. This short review summarizes evidence that exercise may result in a transient worsening of the pre-existing metabolic acidosis that occurs in these patients; a metabolic defect that may reverse the normal anabolic effects of exercise.

Exercise capacity in the heat is greater in the morning than in the evening in man.

PURPOSE: This study investigated the effect of time of day on endurance exercise capacity in a warm environment. METHODS: Nine males cycled to exhaustion at 65% .VO2peak in an ambient temperature of 35 degrees C (60% relative humidity) at 0645 h (AM) and 1845 h (PM). Rectal temperature (Tc), skin temperature (Tsk), and heart rate (HR) were recorded and blood and expired air samples collected at rest every 5 min during exercise and during recovery. RESULTS: Time to exhaustion was longer in the AM trial (45.8 +/- 10.7 min) than in the PM trial (40.5 +/- 9.0 min; P = 0.009). Resting Tc was lower in the AM trial and remained lower for the first 25 min of exercise (P < 0.001). Tc was not different between trials at the point of exhaustion (AM = 38.7 +/- 0.9 degrees C, PM = 38.8 +/- 0.6 degrees C; P = 0.847). Tsk followed a similar pattern, being lower at rest (P = 0.003) and during the initial stages of exercise (P < 0.05) in the AM trial but not different at exhaustion (P = 0.896). The rate of rise of Tc tended to be greater in the AM trial (P = 0.052), and the rate of rise of Tsk (P = 0.032) and of body heat content (P = 0.009) was also greater in the AM trial. HR was initially higher in the PM trial, but there was no difference at exhaustion. There were no differences between trials in blood glucose concentration or plasma volume change. CONCLUSION: The results of this study suggest that endurance exercise capacity in the heat was significantly greater in the morning than the evening, possibly due to a lower initial Tc.