Magnetic and electrical stimulation at different levels of the neuraxis show that supraspinal and spinal factors limit force production in maximal isometric efforts ("central fatigue"). In sustained maximal contractions, motoneurons become less responsive to synaptic input and descending drive becomes suboptimal. Exercise-induced activity in group III and IV muscle afferents acts supraspinally ...

BACKGROUND VO2 may be predicted with base on anthropometric and physiological parameters for determined populations. OBJECTIVE To propose models for submaximal and maximal VO2 prediction in young Brazilian adults. METHODS A total of 137 volunteers (92 men) underwent graded maximal exercise test (GXT) in a cycle ergometer (MonarkTM, Br). Gas exchange and respiratory measurements were perform...

BACKGROUND The aim of this study was to correlate the psychological and health-related quality-of-life status of hemodialysis (HD) patients with recovery indices following maximal and submaximal exercise tests. METHODS Twenty patients on HD (aged 53.5 ± 12.9 years) and 18 healthy individuals (aged 54.1 ± 10.2 years) underwent a maximal and a submaximal cardiopulmonary test (CPETmax and CPETsu...

Caffeine intake results in a decrease in perception of effort, but the cortical substrates of this perceptual effect of caffeine are unknown. The aim of this randomized counterbalanced double-blind crossover study was to investigate the effect of caffeine on the motor-related cortical potential (MRCP) and its relationship with rating of perceived effort (RPE). We also investigated whether MRCP ...

The purpose of this study was to explore the relationship between objectively determined ambulatory activity and simple cardiorespiratory parameters (heart rate and blood pressure at rest and during submaximal exercise) in individuals who were stratified for self-reported participation (yes/any vs. no/none) in vigorous physical activity (PA). Ninety-eight subjects (African Americans: 7 M, 16 F;...

Babault, Nicolas, Michel Pousson, Yves Ballay, and Jacques Van Hoecke. Activation of human quadriceps femoris during isometric, concentric, and eccentric contractions. J Appl Physiol 91: 2628–2634, 2001.—Maximal and submaximal activation level of the right knee-extensor muscle group were studied during isometric and slow isokinetic muscular contractions in eight male subjects. The activation le...

The work of breathing (W(b)) normally incurred during maximal exercise not only requires substantial cardiac output and O(2) consumption (VO(2)) but also causes vasoconstriction in locomotor muscles and compromises leg blood flow (Q(leg)). We wondered whether the W(b) normally incurred during submaximal exercise would also reduce Q(leg). Therefore, we investigated the effects of changing the W(...

Heunks, Leo M. A., Mark J. Cody, Paige C. Geiger, P. N. Richard Dekhuijzen, and Gary C. Sieck. Nitric oxide impairs Ca21 activation and slows cross-bridge cycling kinetics in skeletal muscle. J Appl Physiol 91: 2233–2239, 2001.—The effects of the nitric oxide (NO) donor spermine NONOate (Sp-NO, 1.0 mM) on cross-bridge recruitment and cross-bridge cycling kinetics were studied in permeabilized r...

Panic disorder (PD) patients often report respiratory symptoms and tend to perform poorly during maximal cardiopulmonary exercise testing (CPX), at least partially, due to phobic anxiety. Thus, we hypothesized that a submaximal exercise variable, minimum VE/VO2 - hereafter named cardiorespiratory optimal point (COP) -, may be useful in their clinical assessment. Data from 2,338 subjects were re...

BACKGROUND Football players with groin injury refrain from maximal kicking. Previous groin injury is related to decreased hip range of motion (ROM). Information on ROM differences between maximal and submaximal kicking within players is lacking. The first aim of this study is to quantify ROM of body segments during the maximal (MaxK) and submaximal (SubK) instep kick at four key points. The sec...