Aerobic Exercise Training In Patients Research Articles

Glycaemic control is improved by 7 days of aerobic exercise training in patients with type 2 diabetes

Cardiovascular events and death are better predicted by postprandial glucose (PPG) than by fasting blood glucose or HbA(1c). While chronic exercise reduces HbA(1c) in patients with type 2 diabetes, short-term exercise improves measures of insulin sensitivity but does not consistently alter responses to the OGTT. The purpose of this study was to determine whether short-term exercise training improves PPG and glycaemic control in free-living patients with type 2 diabetes, independently of the changes in fitness, adiposity and energy balance often associated with chronic exercise training. Using continuous glucose monitors, PPG was quantified in previously sedentary patients with type 2 diabetes not using exogenous insulin (n = 13, age 53 ± 2 years, HbA(1c) 6.6 ± 0.2% (49.1 ± 1.9 mmol/mol)) during 3 days of habitual activity and during the final 3 days of a 7 day aerobic exercise training programme (7D-EX) which does not elicit measurable changes in cardiorespiratory fitness or body composition. Diet was standardised across monitoring periods, with modifications during 7D-EX to offset increases in energy expenditure. OGTTs were performed on the morning following each monitoring period. 7D-EX attenuated PPG (p < 0.05) as well as the frequency, magnitude and duration of glycaemic excursions (p < 0.05). Conversely, average 24 h blood glucose did not change, nor did glucose, insulin or C-peptide responses to the OGTT. 7D-EX attenuated glycaemic variability and PPG in free-living patients with type 2 diabetes but did not significantly alter responses to the laboratory-based OGTT. These effects appeared to be independent of changes in fitness, body composition or energy balance. ClinicalTrials.gov numbers: NCT00954109 and NCT00972452. This project was funded by the University of Missouri Institute for Clinical and Translational Sciences (CRM), NIH grant T32 AR-048523 (CRM), Diabetes Action Research and Education Foundation (JPT). Medtronic supplied CGMS sensors at a discounted rate.

Relation of Depression to Severity of Illness in Heart Failure (from Heart Failure And a Controlled Trial Investigating Outcomes of Exercise Training [HF-ACTION

Depression is common in patients with heart failure (HF), prognostic for adverse outcomes and purportedly related to disease severity. Psychological and physiologic factors relevant to HF were assessed in HF-ACTION, a large randomized study of aerobic exercise training in patients with systolic HF. The relation of objective and subjective parameters was compared with scores on the Beck Depression Inventory (BDI) to examine the hypothesis that depressive symptoms are better associated with perception of disease severity than with objective markers of HF severity. At baseline, 2,322 of 2,331 subjects entered into HF-ACTION completed questionnaires to assess depression (BDI) and quality of life (Kansas City Cardiomyopathy Questionnaire [KCCQ]). Objective markers of HF severity included ejection fraction, B-type natriuretic peptide, and peak oxygen consumption (using cardiopulmonary exercise testing, with evaluation of duration and respiratory exchange ratio also performed). Measures more likely to be affected by perceived functional status included New York Heart Association (NYHA) classification and the 6-minute walk test. Objective assessments of disease severity were slightly related (peak oxygen consumption) or not related (B-type natriuretic peptide and ejection fraction) to BDI scores. Using multivariate analysis (KCCQ not included), only age, gender, cardiopulmonary exercise testing duration, NYHA class, 6-minute walk distance, and peak respiratory exchange ratio independently correlated with BDI scores. In conclusion, depression was minimally related to objective assessments of severity of disease in patients with HF, but was associated with patient (and clinician) perceptions of disease severity. Addressing depression might improve symptoms in patients with HF.

Exercise interval training: An improved stimulus for improving the physiology of pre-diabetes

Current reports estimate that type II diabetes (T2D) affects 5-8% of adults. Also recognized is a transitional group of patients whose fasting blood glucose is abnormal; yet, not considered high enough to be diagnosed as diabetes. Defined as "pre-diabetes" these individuals have impaired fasting glucose (IFG; fasting glucose 100-125 mg/dL), impaired glucose tolerance (IGT; 2 h glucose 140-199 mg/dL) or both. Two unifying features associated with IFG and IGT are their strong links to obesity and physical inactivity, which lead independently and collectively toward the erosion of various cellular processes affecting glucose control. In contrast, regular exercise positively influences IFG/IGT and obesity, thus representing an important therapy for preventing diabetes via the enhancement of several mechanisms of action. These include improved glucose metabolism, muscle respiratory capacity, mitochondrial respiratory chain activity and beta-oxidation. Contemporary exercise guidelines provided by various organizations recommend that exercise be performed at intensities ranging from 40% to 85% of maximal aerobic capacity. Unfortunately, little is known regarding the optimal intensity to best facilitate the physiological benefits associated with exercise. An evolving body of research shows that interval training produces greater changes in exercise capacity than traditional aerobic training. Interval training involves bouts of high exercise intensity (15s to 4 min; >90% VO(2max)) followed by a recovery period (40-50% VO(2max)) of equal or longer duration than the associated work interval. Though the net effect of interval training is aerobic, periodic excursions involving anaerobic energy pathways theoretically "push" the mitochondria to greater improvements in exercise capacity, mitochondrial biogenesis, enzymatic markers associated with glycolysis, aerobic metabolism and beta (beta)-oxidation. Though traditionally viewed as a training modality for athletes, a recent report has demonstrated that interval training is more effective than traditional aerobic exercise training in patients up to approximately 75 y of age and with low functional capacities (VO(2max) 13 ml/kg/min) by producing superior improvements in VO(2max), sub-maximal exercise tolerance, levels of peroxisome proliferator activator protein-gamma co-activator1alpha (PGC-1alpha), and quality of life indices more so than traditional aerobic exercise training. Erosion in these same markers is present in populations with pre-diabetes and T2D. The principal hypothesis of this paper is that interval training will provide a more powerful stimulus for improving insulin sensitivity than traditional low-to-moderate intensity aerobic conditioning. This theory further proposes that these affects will be due to greater changes in specific metabolic pathways associated with glycolysis, aerobic metabolism, beta-oxidation, and mitochondrial biogenesis.

Nouveautés dans le traitement des myopathies métaboliques

Metabolic myopathies are inborn errors of intermediate muscle metabolism, presenting either by exercise intolerance, or by progressive muscle weakness. Growing knowledge concerning the pathophysiology of these rare disorders, and the development of new technologies, opens new avenues for the treatment of this group of myopathies. Recent studies showed improvement in exercise capacity after regular aerobic exercise training in patients with McArdle's disease and mitochondrial myopathies. In late-onset Pompe disease enzyme replacement therapy trials with recombinant acid alpha-glucosidase (Myozyme) are currently in progress, the first trials conducted in childhood onset Pompe disease having previously shown a clear improvement in life expectancy and cardiac function. The demonstration that fibrates can induce correction of carnitine palmitoyl-transferase II deficiency in patients cells, lead to the development of an open-labelled therapeutic trial with bezafibrate in patients with CPTII deficiency, which is actually ongoing.

Electrical Stimulation of Skeletal Muscles An Alternative to Aerobic Exercise Training in Patients With Chronic Heart Failure?

The aim of this study was to investigate whether electrical stimulation of skeletal muscles could represent a rehabilitation alternative for patients with chronic heart failure (CHF). Thirty patients with CHF and NYHA class II-III were randomly assigned to a rehabilitation program using either electrical stimulation of skeletal muscles or bicycle training. Patients in the first group (n = 15) had 8 weeks of home-based low-frequency electrical stimulation (LFES) applied simultaneously to the quadriceps and calf muscles of both legs (1 h/day for 7 days/week); patients in the second group (n = 15) underwent 8 weeks of 40 minute aerobic exercise (3 times a week). After the 8-week period significant increases in several functional parameters were observed in both groups: maximal VO2 uptake (LFES group: from 17.5 +/- 4.4 mL/kg/min to 18.3 +/- 4.2 mL/kg/min, P < 0.05; bicycle group: from 18.1 +/- 3.9 mL/kg/min to 19.3 +/- 4.1 mL/kg/min, P < 0.01), maximal workload (LFES group: from 84.3 +/- 15.2 W to 95.9 +/- 9.8 W, P < 0.05; bicycle group: from 91.2 +/- 13.4 W to 112.9 +/- 10.8 W, P < 0.01), distance walked in 6 minutes (LFES group: from 398 +/- 105 m to 435 +/- 112 m, P < 0.05; bicycle group: from 425 +/- 118 m to 483 +/- 120 m, P < 0.03), and exercise duration (LFES group: from 488 +/- 45 seconds to 568 +/- 120 seconds, P < 0.05; bicycle group: from 510 +/- 90 seconds to 611 +/- 112 seconds, P < 0.03). These results demonstrate that an improvement of exercise capacities can be achieved either by classical exercise training or by home-based electrical stimulation. LFES should be considered as a valuable alternative to classical exercise training in patients with CHF.

Upper- vs lower-limb aerobic exercise rehabilitation in patients with symptomatic peripheral arterial disease: A randomized controlled trial

To investigate the effects of a 24-week program of upper- and lower-limb aerobic exercise training on walking performance in patients with symptomatic peripheral arterial disease (PAD) and to study the mechanisms that could influence symptomatic improvement. After approval from the North Sheffield Local Research Ethics Committee, 104 patients (median age, 69 years; range, 50 to 85 years) with stable PAD were randomized into an upper- or lower-limb aerobic exercise training group (UL-Ex or LL-Ex), or to a nonexercise training control group. Training was performed twice weekly for 24 weeks at equivalent relative exercise intensities. An incremental arm- and leg-crank test (ACT and LCT) to maximum exercise tolerance was performed before and at 6, 12, 18, and 24 weeks of the intervention to determine peak oxygen consumption (VO(2)). Walking performance, defined as the claudicating distance (CD) and maximum walking distance (MWD) achieved before intolerable claudication pain, was assessed at the same time points by using a shuttle-walk protocol. Peak blood lactate concentration, Borg ratings of perceived exertion (RPE) and pain category ratio (CR-10) were recorded during all assessments. CD and MWD increased over time (P < .001) in both training groups. At 24 weeks, CD had improved by 51% and 57%, and MWD had improved by 29% and 31% (all P < .001) in the UL-Ex and LL-Ex groups, respectively. An increase in peak heart rate at MWD in the UL-Ex group (109 +/- 4 vs 115 +/- 4 beats/min; P < .01) and LL-Ex group (107 +/- 3 vs 118 +/- 3 beats/min; P = .01) was accompanied by an increase in the amount of pain experienced in both groups (P < .05), suggesting that exercising patients could tolerate a higher level of cardiovascular stress and an increased intensity of claudication pain before test termination after training. Patients assigned to exercise training also showed an increase in LCT peak VO2 at the 24-week time point in relation to baseline (P < .01) and control patients (P < .01), whereas ACT peak VO2 was only improved in the UL-Ex group (P < .05). Our results suggest that a combination of physiologic adaptations and improved exercise pain tolerance account for the improvement in walking performance achieved through upper-limb aerobic exercise training in patients with PAD. Furthermore, that both arm- and leg-crank training could be useful exercise training modalities for improving cardiovascular function, walking performance, and exercise pain tolerance in patients with symptomatic PAD.

Comparison of low-frequency electrical myostimulation and conventional aerobic exercise training in patients with chronic heart failure

Comparison of low-frequency electrical myostimulation and conventional aerobic exercise training in patients with chronic heart failure

Comparison of low-frequency electrical myostimulation and conventional aerobic exercise training in patients with chronic heart failure

Physical training is recommended as an efficient therapy in patients with chronic heart failure (CHF). Low-frequency electrical myostimulation (EMS) has recently been suggested as a good alternative to conventional aerobic training. The aim of this study was to compare the effects of EMS and conventional exercise training in patients with moderate to severe CHF. Twenty-four patients with stable CHF (56.7+/-7.3 years, New York Heart Association grades II and III) underwent 5 weeks of exercise training, 5 h a week, using EMS (n=12) or conventional (n=12) training programmes. At baseline and after the training period, patients performed a symptom-limited cardiopulmonary test, a 6-min and a 200-m walk exercises and an evaluation of maximal knee extensor strength. Oxygen uptake (VO2) and workload at the end of exercise (peak values) and at ventilatory threshold increased after EMS (P< or =0.05) and conventional exercise (P<0.05) training programmes. The slope of the relationship between VO2 and workload was reduced after EMS (P<0.05). The time to recover half of peak VO2 decreased irrespective of the training programme (P<0.001). EMS and conventional exercise training programmes also increased the maximal knee extensor strength (P<0.05), the distance walked in 6 min (P<0.01) and decreased the time elapsed to cover 200 m (P<0.05). These improvements were not statistically different between EMS and conventional exercise. In patients with moderate to severe CHF, 5 weeks of EMS and conventional exercise training produce similar improvements to exercise capacity and muscle performance.

Aerobic exercise effects on patients with lumbar herniated nucleus pulposus

Arthur D. Sculco, MS, Norwich, CT, USA; Donald C. Paup, PhD, Larry F. Hamm, PhD, Washington, DC; Bo Fernhall, PhD, Syracuse, NY, USA; Mario J. Sculco, MD, Norwich, CT, USABackground: There is a paucity of data concerning the effects of aerobic exercise as a treatment for patients with chronic low back pain. Aerobic exercise (AE) is an accepted treatment modality in selected clinical patient populations but has not been previously studied as a sole treatment for patients with symptomatic lumbar herniated nucleus pulposus (HNP).Purpose: The purpose of this study was to assess the effects of moderate intensity AE as the sole exercise intervention in patients with symptomatic lumbar HNP. Clinical outcome measures included assessment of low back pain/symptoms and low back flexibility and function. In addition, changes in body mass index (BMI) and selected cardiovascular fitness variables were analyzed.Study design: This study was a randomized prospective trial involving 75 patients with symptomatic lumbar HNP.Patient sample: After screening 87 symptomatic patients with lumbar HNP being treated in a private neurosurgical practice, 79 patients met study inclusionary criteria, and 75 volunteered for this prospective AE research study.Outcome measures: Clinical outcome measures included the sit-and-reach (SR), functional reach (FR) and trunk forward flexion (TFF) tests and the following five visual analog scales: low back pain/symptoms (LBPS), pain/symptoms above knee (AK), pain/symptoms below knee (BK), activities of daily living (ADL) and occupational work capacity (OWC). Physiologic outcomes included BMI, resting heart rate (HR) and blood pressure (BP), oxygen pulse and pulse recovery test.Methods: A total of 75 patients with symptomatic lumbar HNP were randomized into an AE and a control group (C) group. All were assessed at baseline after randomization and again after 12 weeks of AE training. The AE prescription was walking or cycling at 70% of age-predicted maximal heart rate, 4 days per week, for 45 minutes per session. All patients exercised unsupervised at home. The C group patients continued receiving usual care, as did the AE patients. In addition to descriptive statistics, group mean differences were analyzed using t tests. Statistical significance was set at the .05 level.Results: AE training resulted in significant improvements in HR, oxygen pulse and the pulse recovery test. The only functional test result reaching significance was SR. Three of the five visual analog scores assessing symptoms or function improved significantly: LBPS, ADL and BK. Improvement in the remaining two visual analog scales approached significance (OWC, p=.076; AK, p=.056). Patients reported no untoward effects of the AE program.Conclusions: Moderate-intensity AE training in patients with symptomatic lumbar HNP is safe and associated with improvements in physiological variables, functional scores and symptomatic pain.