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Leg Exercise (leg + exercise)

Distribution by Scientific Domains

Life Sciences	75%
Medical Sciences	25%

Selected Abstracts

Cardiorespiratory, Metabolic, and Biomechanical Responses During Functional Electrical Stimulation Leg Exercise: Health and Fitness Benefits

ARTIFICIAL ORGANS, Issue 4 2009
Fahad Aziz MD
No abstract is available for this article. [source]

Chest wall kinematics, respiratory muscle action and dyspnoea during arm vs. leg exercise in humans

ACTA PHYSIOLOGICA, Issue 1 2006
I. Romagnoli
Abstract Aim:, We hypothesize that different patterns of chest wall (CW) kinematics and respiratory muscle coordination contribute to sensation of dyspnoea during unsupported arm exercise (UAE) and leg exercise (LE). Methods:, In six volunteer healthy subjects, we evaluated the volumes of chest wall (Vcw) and its compartments, the pulmonary apposed rib cage (Vrc,p), the diaphragm-abdomen apposed rib cage (Vrc,a) and the abdomen (Vab), by optoelectronic plethysmography. Oesophageal, gastric and trans-diaphragmatic pressures were simultaneously measured. Chest wall relaxation line allowed the measure of peak rib cage inspiratory muscle, expiratory muscle and abdominal muscle pressures. The loop Vrc,p/Vrc,a allowed the calculation of rib cage distortion. Dyspnoea was assessed by a modified Borg scale. Results:, There were some differences and similarities between UAE and LE. Unlike LE with UAE: (i) Vcw and Vrc,p at end inspiration did not increase, whereas a decrease in Vrc,p contributed to decreasing CW end expiratory volume; (ii) pressure production of inspiratory rib cage muscles did not significantly increase from quiet breathing. Not unlike LE, the diaphragm limited its inspiratory contribution to ventilation with UAE with no consistent difference in rib cage distortion between UAE and LE. Finally, changes in abdominal muscle pressure, and inspiratory rib cage muscle pressure predicted 62% and 41.4% of the variability in Borg score with UAE and LE, respectively (P < 0.01). Conclusion:, Leg exercise and UAE are associated with different patterns of CW kinematics, respiratory muscle coordination, and production of dyspnoea. [source]

Arm and leg substrate utilization and muscle adaptation after prolonged low-intensity training

ACTA PHYSIOLOGICA, Issue 4 2010
J. W. Helge
Abstract This review will focus on current data where substrate metabolism in arm and leg muscle is investigated and discuss the presence of higher carbohydrate oxidation and lactate release observed during arm compared with leg exercise. Furthermore, a basis for a possible difference in substrate partitioning between endogenous and exogenous substrate during arm and leg exercise will be debated. Moreover the review will probe if differences between arm and leg muscle are merely a result of different training status rather than a qualitative difference in limb substrate regulation. Along this line the review will address the available studies on low-intensity training performed separately with arm or legs or as whole-body training to evaluate if this leads to different adaptations in arm and leg muscle resulting in different substrate utilization patterns during separate arm or leg exercise at comparable workloads. Finally, the influence and capacity of low-intensity training to influence metabolic fitness in the face of a limited effect on aerobic fitness will be challenged. [source]

Stroke volume decreases during mild dynamic and static exercise in supine humans

ACTA PHYSIOLOGICA, Issue 2 2009
M. Elstad
Abstract Aim:, The contributions of cardiac output (CO) and total peripheral resistance to changes in arterial blood pressure are debated and differ between dynamic and static exercise. We studied the role stroke volume (SV) has in mild supine exercise. Methods:, We investigated 10 healthy, supine volunteers by continuous measurement of heart rate (HR), mean arterial blood pressure, SV (ultrasound Doppler) and femoral beat volume (ultrasound Doppler) during both dynamic mild leg exercise and static forearm exercise. This made it possible to study CO, femoral flow (FF) and both total and femoral peripheral resistance beat-by-beat. Results:, During a countdown period immediately prior to exercise, HR and mean arterial pressure increased, while SV decreased. During mild supine exercise, SV decreased by 5,8%, and most of this was explained by increased mean arterial pressure. Dynamic leg exercise doubled femoral beat volume, while static hand grip decreased femoral beat volume by 18%. FF is tightly regulated according to metabolic demand during both dynamic leg exercise and static forearm exercise. Conclusion:, Our three major findings are, firstly, that SV decreases during both dynamic and static mild supine exercise due to an increase in mean arterial pressure. Secondly, femoral beat volume decreases during static hand grip, but FF is unchanged due to the increase in HR. Finally, anticipatory responses to exercise are apparent prior to both dynamic and static exercise. SV changes contribute to CO changes and should be included in studies of central haemodynamics during exercise. [source]

Chest wall kinematics, respiratory muscle action and dyspnoea during arm vs. leg exercise in humans

The interaction of central command and the exercise pressor reflex in mediating baroreflex resetting during exercise in humans

EXPERIMENTAL PHYSIOLOGY, Issue 1 2006
Kevin M. Gallagher
Central command and the exercise pressor reflex can independently reset the carotid baroreflex (CBR) during exercise. The present investigation assessed the interactive relationship between these two neural mechanisms in mediating baroreflex resetting during exercise. Six men performed static leg exercise at 20% maximal voluntary contraction under four conditions: control, no perturbation; neuromuscular blockade (NMB) induced by administration of the neuromuscular blocking agent Norcuron (central command activation); MAST, application of medical antishock trousers inflated to 100 mmHg (exercise pressor reflex activation); and Combo, NMB plus MAST (concomitant central command and exercise pressor reflex activation). With regard to CBR control of heart rate (HR), both NMB and Combo conditions resulted in a further resetting of the carotid,cardiac stimulus,response curve compared to control conditions, suggesting that CBR,HR resetting is predominately mediated by central command. In contrast, it appears that CBR control of blood pressure can be mediated by signals from either central command or the exercise pressor reflex, since both NMB and MAST conditions equally augmented the resetting of the carotid,vasomotor stimulus,response curve. With regard to the regulation of both HR and blood pressure, the extent of CBR resetting was greater during the Combo condition than during overactivation of either central command or the exercise pressor reflex alone. Therefore, we suggest that central command and the exercise pressor reflex interact such that signals from one input facilitate signals from the other, resulting in an enhanced resetting of the baroreflex during exercise. [source]

Effect of leg exercises on popliteal venous blood flow during prolonged immobility of seated subjects: implications for prevention of travel-related deep vein thrombosis

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 9 2007
K. HITOS
Summary.,Background:,Venous stasis is an important contributing factor in the development of travel-related deep vein thrombosis. This study examined factors affecting popliteal venous blood flow in order to determine the most effective exercise regimen to prevent venous stasis. Methods:,Twenty-one healthy subjects were randomly assigned to various activities over a 9-week period. Subjects remained seated throughout the investigation and 3660 duplex ultrasound examinations were performed by a single examiner using a SonoSite 180 Plus handheld ultrasound. Baseline popliteal vein blood flow velocity, cross-sectional area and volume flow in subjects sitting motionless were assessed in the first 3 weeks. The remaining 6 weeks involved subjects performing airline-recommended activities, foot exercises, foot exercises against moderate resistance and foot exercises against increased resistance in order to determine the most beneficial method for enhancing popliteal venous flow. Sitting with feet not touching the floor and the effect of sleeping were also assessed. Results:,The median age of the subjects was 22 years (range: 18,25.5 years), height 171 cm (162.5,180.5 cm) and body mass index 25.3 kg m,2 (23.2,26.3 kg m,2). Blood volume flow in the popliteal vein was reduced by almost 40% with immobility of seated subjects and by almost 2-fold when sitting motionless with feet not touching the floor. Foot exercises against increased resistance positively enhanced volume flow (P < 0.0001). Conclusion:,Leg exercise regimens enhanced popliteal venous flow during prolonged immobility of seated subjects, reinforcing the importance of regular leg movement to prevent venous stasis during prolonged sitting, such as in long-distance travel. [source]