Ad Williams

Moderate-intensity resistance exercise training in patients with chronic heart failure improves strength, endurance, heart rate variability, and forearm blood flow

BACKGROUND Resistance exercise training was applied to patients with chronic heart failure (CHF) on the basis that it may partly reverse deficiencies in skeletal muscle strength and endurance, aerobic power (VO(2peak)), heart rate variability (HRV), and forearm blood flow (FBF) that are all putative factors in the syndrome. METHODS AND RESULTS Thirty-nine CHF patients (New York Heart Association Functional Class=2.3+/-0.5; left ventricular ejection fraction 28%+/-7%; age 65+/-11 years; 33:6 male:female) underwent 2 identical series of tests, 1 week apart, for strength and endurance of the knee and elbow extensors and flexors, VO(2peak), HRV, FBF at rest, and FBF activated by forearm exercise or limb ischemia. Patients were then randomized to 3 months of resistance training (EX, n=19), consisting of mainly isokinetic (hydraulic) ergometry, interspersed with rest intervals, or continuance with usual care (CON, n=20), after which they underwent repeat endpoint testing. Combining all 4 movement patterns, strength increased for EX by 21+/-30% (mean+/-SD, P<.01) after training, whereas endurance improved 21+/-21% (P<.01). Corresponding data for CON remained almost unchanged (strength P<.005, endurance P<.003 EX versus CON). VO(2peak) improved in EX by 11+/-15% (P<.01), whereas it decreased by 10+/-18% (P<.05) in CON (P<.001 EX versus CON). The ratio of low-frequency to high-frequency spectral power fell after resistance training in EX by 44+/-53% (P<.01), but was unchanged in CON (P<.05 EX versus CON). FBF increased at rest by 20+/-32% (P<.01), and when stimulated by submaximal exercise (24+/-32%, P<.01) or limb ischemia (26+/-45%, P<.01) in EX, but not in CON (P<.01 EX versus CON). CONCLUSIONS Moderate-intensity resistance exercise training in CHF patients produced favorable changes to skeletal muscle strength and endurance, VO(2peak), FBF, and HRV.

Effect of Intradialytic Versus Home-Based Aerobic Exercise Training on Physical Function and Vascular Parameters in Hemodialysis Patients: A Randomized Pilot Study

BACKGROUND Hemodialysis patients show reduced physical function and greater risk of increased arterial stiffness because of hypertension, metabolic disturbances, and vascular calcification. Exercise interventions potentially could improve their vascular risk profile. STUDY DESIGN Randomized controlled pilot clinical study comparing the effects of 6 months of supervised intradialytic exercise training versus home-based exercise training or usual care on physical function and arterial stiffness in hemodialysis patients. SETTING & PARTICIPANTS 70 hemodialysis patients from 3 renal units. INTERVENTION Intradialytic-exercise patients trained 3 times/wk for 6 months on a cycle ergometer and home-based-exercise patients followed a walking program to achieve the same weekly physical activity. Usual-care patients received no specific intervention. OUTCOMES & MEASUREMENTS Primary outcome measures were distance traveled during a 6-minute walk test and aortic pulse wave velocity. Secondary outcome measures included augmentation index (augmentation pressure as a percentage of central pulse pressure), peripheral (brachial) and central blood pressures (measured noninvasively using radial tonometry), physical activity, and self-reported physical functioning. Measurements were made at baseline and 6 months. RESULTS At 6 months, there were no significant differences between changes in 6-minute walk test distance (intradialytic exercise, +14%; home-based exercise, +11%; usual care, +5%), pulse wave velocity (intradialytic exercise, -4%; home-based exercise, -2%; usual care, +5%), or any secondary outcome measure. LIMITATIONS Lack of medication data limited the analysis of vascular parameters in this study. CONCLUSION There were no differences between intradialytic or home-based exercise training and usual care for either physical function or vascular parameters.

Creatine supplementation enhances muscle force recovery after eccentrically-induced muscle damage in healthy individuals

BackgroundEccentric exercise-induced damage leads to reductions in muscle force, increased soreness, and impaired muscle function. Creatine monohydrates (Cr) ergogenic potential is well established; however few studies have directly examined the effects of Cr supplementation on recovery after damage. We examined the effects of Cr supplementation on muscle proteins and force recovery after eccentrically-induced muscle damage in healthy individuals.MethodsFourteen untrained male participants (22.1 ± 2.3 yrs, 173 ± 7.7 cm, 76.2 ± 9.3 kg) were randomly separated into 2 supplement groups: i) Cr and carbohydrate (Cr-CHO; n = 7); or ii) carbohydrate (CHO; n = 7). Participants consumed their supplement for a period of 5 days prior to, and 14 days following a resistance exercise session. Participants performed 4 sets of 10 eccentric-only repetitions at 120% of their maximum concentric 1-RM on the leg press, leg extension and leg flexion exercise machine. Plasma creatine kinase (CK) and lactate dehydrogenase (LDH) activity were assessed as relevant blood markers of muscle damage. Muscle strength was examined by voluntary isokinetic knee extension using a Cybex dynamometer. Data were analyzed using repeated measures ANOVA with an alpha of 0.05.ResultsThe Cr-supplemented group had significantly greater isokinetic (10% higher) and isometric (21% higher) knee extension strength during recovery from exercise-induced muscle damage. Furthermore, plasma CK activity was significantly lower (by an average of 84%) after 48 hrs (P < 0.01), 72 hrs (P < 0.001), 96 hrs (P < 0.0001), and 7 days (P < 0.001) recovery in the Cr-supplemented group.ConclusionThe major finding of this investigation was a significant improvement in the rate of recovery of knee extensor muscle function after Cr supplementation following injury.

Exercise & Sports Science Australia (ESSA) position statement on exercise and chronic kidney disease

OBJECTIVES Chronic kidney disease (CKD) is prevalent, affecting 13% of adult Australians and poses increased risk for cardiovascular morbidity and mortality. This position article provides evidence-based guidelines on the role of exercise training for CKD patients and provides recommendations for prescribing and delivering exercise training. DESIGN Position stand. METHODS Synthesis of published work within the field of exercise training and chronic kidney disease. RESULTS Exercise training likely to provide benefits to CKD patients, including improvements in cardio-respiratory fitness, quality of life, sympatho-adrenal activity, muscle strength and increased energy intake and possible reduction in inflammatory biomarkers. Existing studies generally report small sample sizes, brief training periods and relatively high attrition rates. Exercise training appears to be safe for CKD patients with no deaths directly related to exercise training in over 30,000 patient-hours, although strict medical exclusion criteria in previous studies resulted in 25% of patients being excluded potentially impacting the generalisability of the findings. CONCLUSIONS Aerobic exercise at an intensity of >60% of maximum capacity is recommended to improve cardio-respiratory fitness. Few data are available on resistance training and it is unclear whether this form of training retards catabolic/inflammatory processes typical of CKD. However, it should be considered important due to its proven beneficial effects on bone density and muscle mass. Due to the high prevalence and incidence of co-morbidities in CKD patients, exercise training programs should be prescribed and delivered by individuals with appropriate qualifications and experience to recognise and accommodate co-morbidities and associated complications.

The long-term benefits of a multi-component exercise intervention to balance and mobility in healthy older adults.

We examined the long-term effects of a multi-component exercise program on balance, mobility and exercise behavior. The benefits of a community-based resistance and flexibility exercise intervention in a group of healthy older (60-75 years) individuals were recorded 12 months after completion of the randomized control intervention. Differences between those participants who continued to exercise and those who discontinued were investigated. Significant improvements from baseline in sit to stand (p<0.001), timed up and go (p=0.001), and sway (p<0.001) remained at follow up in the exercise intervention group, with a control group unchanged. Participants who continued exercising had significantly greater improvements in strength immediately after the intervention, compared to those who discontinued (p=0.004). Those who continued regular resistance training performed better in the step test at 12-month follow up (p=0.009) and believed that the program was of more benefit to their physical activity (p<0.001) than those who discontinued exercising. Benefits to balance and mobility persist 1 year after participation in a multi-component exercise program, due in part to some continuing participation in resistance training. Motivation to continue resistance training may be related real and perceived benefits attained from the intervention as well as the environmental context of the intervention.

Exercise & Sports Science Australia Position Statement on exercise training and chronic heart failure

Chronic heart failure (CHF) is a complex syndrome characterised by progressive decline in left ventricular function, low exercise tolerance and raised mortality and morbidity. Regular exercise participation has been shown to be a safe and effective treatment modality in the majority of CHF patients, partially reversing some of the maladaptations evident in myocardial and skeletal muscle function, and resulting in improvements in physical fitness and quality of life, and perhaps reduced mortality. The volume and intensity of exercise that is recommended depends on the syndrome severity, however in most patients it should consist of a combination of low-to-moderate intensity aerobic (endurance) exercise on most days of the week and individually prescribed low-to-moderate intensity resistance (strength) training at least twice per week. Additionally, all patients should be closely monitored prior to and during exercise for contraindications by an appropriately trained health professional. The purpose of this statement is to inform and guide exercise practitioners and health professionals in the safe and effective prescription and supervision of exercise for patients with CHF.

Defects in Mitochondrial ATP Synthesis in Dystrophin-Deficient Mdx Skeletal Muscles May Be Caused by Complex I Insufficiency

Duchenne Muscular Dystrophy is a chronic, progressive and ultimately fatal skeletal muscle wasting disease characterised by sarcolemmal fragility and intracellular Ca2+ dysregulation secondary to the absence of dystrophin. Mounting literature also suggests that the dysfunction of key energy systems within the muscle may contribute to pathological muscle wasting by reducing ATP availability to Ca2+ regulation and fibre regeneration. No study to date has biochemically quantified and contrasted mitochondrial ATP production capacity by dystrophic mitochondria isolated from their pathophysiological environment such to determine whether mitochondria are indeed capable of meeting this heightened cellular ATP demand, or examined the effects of an increasing extramitochondrial Ca2+ environment. Using isolated mitochondria from the diaphragm and tibialis anterior of 12 week-old dystrophin-deficient mdx and healthy control mice (C57BL10/ScSn) we have demonstrated severely depressed Complex I-mediated mitochondrial ATP production rate in mdx mitochondria that occurs irrespective of the macronutrient-derivative substrate combination fed into the Kreb’s cycle, and, which is partially, but significantly, ameliorated by inhibition of Complex I with rotenone and stimulation of Complex II-mediated ATP-production with succinate. There was no difference in the MAPR response of mdx mitochondria to increasing extramitochondrial Ca2+ load in comparison to controls, and 400 nM extramitochondrial Ca2+ was generally shown to be inhibitory to MAPR in both groups. Our data suggests that DMD pathology is exacerbated by a Complex I deficiency, which may contribute in part to the severe reductions in ATP production previously observed in dystrophic skeletal muscle.

Yoga management of breast cancer-related lymphoedema: a randomised controlled pilot-trial.

BackgroundSecondary arm lymphoedema continues to affect at least 20% of women after treatment for breast cancer requiring lifelong professional treatment and self-management. The holistic practice of yoga may offer benefits as an adjunct self-management option. The aim of this small pilot trial was to gain preliminary data to determine the effect of yoga on women with stage one breast cancer-related lymphoedema (BCRL). This paper reports the results for the primary and secondary outcomes.MethodsParticipants were randomised, after baseline testing, to receive either an 8-week yoga intervention (n = 15), consisting of a weekly 90-minute teacher-led class and a 40-minute daily session delivered by DVD, or to a usual care wait-listed control group (n = 13). Primary outcome measures were: arm volume of lymphoedema measured by circumference and extra-cellular fluid measured by bioimpedance spectroscopy. Secondary outcome measures were: tissue induration measured by tonometry; levels of sensations, pain, fatigue, and their limiting effects all measured by a visual analogue scale (VAS) and quality of life based on the Lymphoedema Quality of Life Tool (LYMQOL). Measurements were conducted at baseline, week 8 (post-intervention) and week 12 (four weeks after cessation of the intervention).ResultsAt week 8, the intervention group had a greater decrease in tissue induration of the affected upper arm compared to the control group (p = 0.050), as well as a greater reduction in the symptom sub-scale for QOL (p = 0.038). There was no difference in arm volume of lymphoedema or extra-cellular fluid between groups at week 8; however, at week 12, arm volume increased more for the intervention group than the control group (p = 0.032).ConclusionsAn 8-week yoga intervention reduced tissue induration of the affected upper arm and decreased the QOL sub-scale of symptoms. Arm volume of lymphoedema and extra-cellular fluid did not increase. These benefits did not last on cessation of the intervention when arm volume of lymphoedema increased. Further research trials with a longer duration, higher levels of lymphoedema and larger numbers are warranted before definitive conclusions can be made.

Reliability of isokinetic strength and aerobic power testing for patients with chronic heart failure

PURPOSE The objective of this study was to assess the reliability of testing skeletal muscle strength and peak aerobic power in a clinical population of patients with chronic heart failure (CHF). METHODS Thirty-three patients with CHF (New York Heart Association (NYHA) Functional Class 2.3 +/- 0.5; left ventricular ejection fraction 27% +/- 7%; age 65 +/- 9 years; 28:5 male-female ratio) underwent two identical series of tests (T1 and T2), 1 week apart, for strength and endurance of the muscle groups responsible for knee extension/flexion and elbow extension/flexion. The patients also underwent two graded exercise tests on a bicycle ergometer to measure peak oxygen consumption (VO(2peak)). Three months later, 18 of the patients underwent a third test (T3) for each of the measures. Means were compared using MANOVA with repeated measures for strength and endurance, and ANOVA with repeated measures for VO(2peak). RESULTS Combining data for all four movement patterns, the expression of strength increased from T1 to T2 by 12% +/- 25% (P <.001; intraclass correlation coefficient [ICC] = 0.89). Correspondingly, endurance increased by 13% +/- 23% (P =.004; ICC = 0.87). Peak oxygen consumption was not significantly different (16.2 +/- 0.8 and 16.1 +/- 0.8 mL.kg(-1).min(-1) for T1 and T2, respectively; P =.686; ICC = 0.91). There were no significant differences between T2 and T3 for strength (2% +/- 17%; P =.736; ICC = 0.92) or muscle endurance (-1% +/- 15%; P =.812; ICC = 0.96), but VO(2peak) decreased from 16.7 +/- 1.2 to 14.9 +/- 0.9 mL.kg(-1).min(-1) (-10% +/- 18%; P =.021; ICC = 0.89). CONCLUSIONS These data suggest that in a population of patients with CHF, a familiarization trial for skeletal muscle strength testing is necessary. Although familiarization is not required for assessing oxygen consumption as a single measurement, VO(2peak) declined markedly in the 3-month period for which these patients were followed. Internal consistency within patients was high for the second and third strength trials and the first and second tests of VO(2peak).

The effect of yoga on women with secondary arm lymphoedema from breast cancer treatment

BackgroundWomen who develop secondary arm lymphoedema subsequent to treatment associated with breast cancer require life-long management for a range of symptoms including arm swelling, heaviness, tightness in the arm and sometimes the chest, upper body impairment and changes to a range of parameters relating to quality of life. While exercise under controlled conditions has had positive outcomes, the impact of yoga has not been investigated. The aim of this study is to determine the effectiveness of yoga in the physical and psycho-social domains, in the hope that women can be offered another safe, holistic modality to help control many, if not all, of the effects of secondary arm lymphoedema.Methods and designA randomised controlled pilot trial will be conducted in Hobart and Launceston with a total of 40 women receiving either yoga intervention or current best practice care. Intervention will consist of eight weeks of a weekly teacher-led yoga class with a home-based daily yoga practice delivered by DVD. Primary outcome measures will be the effects of yoga on lymphoedema and its associated symptoms and quality of life. Secondary outcome measures will be range of motion of the arm and thoracic spine, shoulder strength, and weekly and daily physical activity. Primary and secondary outcomes will be measured at baseline, weeks four, eight and a four week follow up at week twelve. Range of motion of the spine, in a self-nominated group, will be measured at baseline, weeks eight and twelve. A further outcome will be the women’s perceptions of the yoga collected by interview at week eight.DiscussionThe results of this trial will provide information on the safety and effectiveness of yoga for women with secondary arm lymphoedema from breast cancer treatment. It will also inform methodology for future, larger trials.Trial registrationACTRN12611000202965