56 research outputs found

    benefits of aerobic exercise training with recommendations for healthy aging

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    The purpose of this article is to provide an overview on the importance of aerobic exercise and its characteristics for healthy aging. The first section briefly reviews the effects of aging on maximal aerobic power; Section 2 considers the effects of aerobic exercise training, and Section 3 summarizes the recommendations and some limitations of the current guidelines for aerobic exercise training. Physical activity cannot stop the biological aging processes; however, there is evidence that regular aerobic exercise can minimize the physiological effects of an otherwise sedentary lifestyle and increase active life expectancy by limiting the development and progression of chronic disease and disability conditions. The use of moderately standardized guidelines for exercise prescription resulted in safe and effective impact on health-related outcomes

    Tensiomyography detects early hallmarks of bed-rest-induced atrophy before changes in muscle architecture.

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    In young and older people skeletal muscle mass is reduced after as little as seven days of disuse. The declines in muscle mass after such short periods are of high clinical relevance, particularly in older people who show higher atrophy rate, and a slower, or even a complete lack of muscle mass recovery after disuse. Ten men (24.3± 2.6 years) underwent 35 days of 6° head-down tilt bed rest followed by 30 days of recovery. During bed rest, a neutral energy balance was maintained, with three weekly passive physiotherapy sessions to minimise muscle soreness and joint stiffness. All measurements were performed in a hospital at days 1-10 (BR1-BR10), day 16 (BR16), 28 (BR28) and 35 (BR35) of bed rest, and day 1 (R+1), 3 (R+3) and 30 (R+30) after reambulation. Vastus medialis obliquus (VMO), vastus medialis longus (VML) and biceps femoris (BF) thickness (d) and pennation angle (Θ) were assessed by ultrasonography, while twitch muscle belly displacement (Dm) and contraction time (Tc) were assessed with tensiomyography. After bed rest, d and Θ decreased by 13-17% in all muscles (P<.001) and had recovered at R+30. Dm was increased by 42.3-84.4% (P<.001) at BR35 and preceded the decrease in d by 7, 5 and 3 days in VMO, VML and BF, respectively. Tc increased only in BF (32.1%; P<.001) and was not recovered at R+30. Tensiomyography can detect early bed-rest-induced changes in muscle with higher sensitivity before overt architectural changes and atrophy can be detected

    Computerized cognitive training and brain derived neurotrophic factor during bed rest: Mechanisms to protect individual during acute stress

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    Acute stress, as bed rest, was shown to increase plasma level of the neurotrophin brain-derived neurotrophic factor (BDNF) in older, but not in young adults. This increase might represent a protective mechanism towards acute insults in aging subjects. Since computerized cognitive training (CCT) is known to protect brain, herein we evaluated the effect of CCT during bed rest on BDNF, muscle mass, neuromuscular function and metabolic parameters. The subjects that underwent CCT did not show an increase of BDNF after bed rest, and showed an anti-insular modification pattern in metabolism. Neuromuscular function parameters, already shown to beneficiate from CCT, negatively correlated with BDNF in research participants undergoing CCT, while positively correlated in the control group. In conclusion, BDNF increase can be interpreted as a standardized protective mechanism taking place whenever an insult occurs; it gives low, but consistent preservation of neuromuscular function. CCT, acting as an external protective mechanism, seems to modify this standardized response, avoiding BDNF increase or possibly modifying its time course. Our results suggest the possibility of differential neuroprotective mechanisms among ill and healthy individuals, and the importance of timing in determining the effects of protective mechanism

    Effects of Lumbosacral Spinal Cord Epidural Stimulation for Standing after Chronic Complete Paralysis in Humans

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    <div><p>Sensory and motor complete spinal cord injury (SCI) has been considered functionally complete resulting in permanent paralysis with no recovery of voluntary movement, standing or walking. Previous findings demonstrated that lumbosacral spinal cord epidural stimulation can activate the spinal neural networks in one individual with motor complete, but sensory incomplete SCI, who achieved full body weight-bearing standing with independent knee extension, minimal self-assistance for balance and minimal external assistance for facilitating hip extension. In this study, we showed that two clinically sensory and motor complete participants were able to stand over-ground bearing full body-weight without any external assistance, using their hands to assist balance. The two clinically motor complete, but sensory incomplete participants also used minimal external assistance for hip extension. Standing with the least amount of assistance was achieved with individual-specific stimulation parameters, which promoted overall continuous EMG patterns in the lower limbs’ muscles. Stimulation parameters optimized for one individual resulted in poor standing and additional need of external assistance for hip and knee extension in the other participants. During sitting, little or negligible EMG activity of lower limb muscles was induced by epidural stimulation, showing that the weight-bearing related sensory information was needed to generate sufficient EMG patterns to effectively support full weight-bearing standing. In general, electrode configurations with cathodes selected in the caudal region of the array at relatively higher frequencies (25–60 Hz) resulted in the more effective EMG patterns for standing. These results show that human spinal circuitry can generate motor patterns effective for standing in the absence of functional supraspinal connections; however the appropriate selection of stimulation parameters is critical.</p></div

    EMG and ground reaction force recorded during standing with different stimulation amplitudes.

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    <p>EMG and ground reaction force recorded from participant A53 during standing with three different stimulation amplitudes (1.0, 3.0 and 5.0 V) delivered at either 25 Hz or 50 Hz. Electrode configuration (cathodes in black, anodes in grey, and non-active in white) is reported. MH: medial hamstring; VL: vastus lateralis; TA: tibialis anterior; SOL: soleus.</p
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