Intensity-dependent effects of cycling exercise on corticospinal excitability in healthy humans: a pilot study

Abstract Aims the aim of this study was to verify the effects of different intensities of locomotor exercise on corticospinal excitability. Methods 18 healthy subjects (27.6 ± 6.5 years,) participated in a design study of three different exercise protocols on a cycle ergometer: (i) 10 min at 75% Wmax (high intensity); (ii) 15min at 60% Wmax (moderate intensity) or (iii) 30 min at 45% Wmax (low intensity). The protocols of lower body cycling were assigned in random order in separate sessions. A control session was done with subjects at rest. Corticospinal excitability was assessed before (baseline) and every 5 min for 15min after the end of exercise/rest (time: 0, 5, 10 and 15) by measurement of the motor evoked potential (MEP) elicited by transcranial magnetic stimulation in the relaxed first-dorsal interosseus muscle. Results Compared to the resting session, a significant decrease (64%) in the motor evoked potential amplitudes was found only in the session of exercise of high intensity. This result seems depend on the level of physical activity of subject. No change was found after rest, low and moderate exercises. Conclusions These findings suggest that changes in the corticospinal excitability depend on exercise intensity and level of physical activity of subjects.(AU)

Effects of inspiratory muscle training in elderly women on respiratory muscle strength, diaphragm thickness and mobility.

BACKGROUND: Aging results in a decline in the function of the respiratory muscles. Inspiratory muscle training is emerging as a possible intervention to attenuate the decline of respiratory muscles in the elderly. The aim of this study was to evaluate the efficacy of inspiratory muscle training on respiratory strength, diaphragm thickness, and diaphragmatic mobility in elderly women. METHODS: This was a controlled, randomized, and double-blind clinical trial, performed on 22 elderly women distributed in two groups, training (TG) and control (CG). Over an 8-week period a moderate intensity inspiratory muscle training protocol was followed in the TG, while CG followed a sham protocol. In addition maximum expiratory and inspiratory pressure, mobility of the diaphragm and diaphragmatic thickness were evaluated by ultrasound. RESULTS: After training, in TG maximal inspiratory pressure, maximal expiratory pressure, diaphragm thickness, and mobility increased by 37%, 13%, 11%, and 9% respectively, and their values were significantly higher than CG (p < .005, p = .013, p = .001, and p = .001). CONCLUSION: Inspiratory muscle training of moderate intensity improves respiratory muscle strength, diaphragm thickness, and diaphragm mobility in elderly women and it should be considered to minimize changes associated with senescence.