Effects of photobiomodulation on the fatigue level in elderly women: an isokinetic dynamometry evaluation.

Aging is responsible by a series of morphological and functional modifications that lead to a decline of muscle function, particularly in females. Muscle tissue in elderly people is more susceptible to fatigue and, consequently, to an increased inability to maintain strength and motor control. In this context, therapeutic approaches able of attenuating muscle fatigue have been investigated. Among these, the photobiomodulation demonstrate positive results to interacts with biological tissues, promoting the increase in cell energy production. Thus, the aim of this study was to investigate the effects of photobiomodulation (808 nm, 250 J/cm(2), 100 mW, 7 J each point) in the fatigue level and muscle performance in elderly women. Thirty subjects entered a crossover randomized double-blinded placebo-controlled trial. Photobiomodulation was delivered on the rectus femoris muscle of the dominant limb immediately before the fatigue protocol. In both sessions, peripheral muscle fatigue was analyzed by surface electromyography (EMG) and blood lactate analysis. Muscle performance was evaluated using an isokinetic dynamometer. The results showed that photobiomodulation was able of reducing muscle fatigue by a significant increase of electromyographic fatigue index (EFI) (p = 0.047) and decreasing significantly lactate concentration 6 min after the performance of the fatigue protocol (p = 0. 0006) compared the placebo laser session. However, the photobiomodulation was not able of increasing muscle performance measured by the isokinetic dynamometer. Thus, it can be conclude that the photobiomodulation was effective in reducing fatigue levels. However, no effects of photobiomodulation on muscle performance was observed.

Effects of a physical fitness program on memory and blood viscosity in sedentary elderly men.

The aim of this study was to investigate the effects of a 6-month exercise program on cognitive function and blood viscosity in sedentary elderly men. Forty-six healthy inactive men, aged 60-75 years were randomly distributed into a control group (n=23) and an experimental group (n=23). Participants underwent blood analysis and physical and memory evaluation, before and after the 6-month program of physical exercise. The control group was instructed not to alter its everyday activities; the experimental group took part in the fitness program. The program was conducted using a cycle ergometer, 3 times per week on alternate days, with intensity and volume individualized at ventilatory threshold 1. Sessions were continuous and maximum duration was 60 min each. There was significant improvement in memory (21%; P<0.05), decreased blood viscosity (-19%; P<0.05), and higher aerobic capacity (48%; P<0.05) among participants in the experimental group compared with the control group. These data suggest that taking part in an aerobic physical fitness program at an intensity corresponding to ventilatory threshold-1 may be considered a nonmedication alternative to improve physical and cognitive function.

Resistance exercise: a non-pharmacological strategy to minimize or reverse sleep deprivation-induced muscle atrophy.

Sleep is important for maintenance of skeletal muscle health. Sleep debt can induce muscle atrophy by increasing glucocorticoids and decreasing testosterone, growth hormone and insulin-like growth factor-I. These hormonal alterations result in a highly proteolytic environment characterized by decreased protein synthesis and increased degradation. Given that sleep deprivation is increasingly prevalent in modern society, strategies to minimize or reverse its adverse effects need to be investigated. Resistance exercise has been suggested as an intervention that would benefit the muscle health. The practice of this type of exercise can increase the concentration of testosterone, growth hormone and insulin-like growth factor I and stimulate the protein synthesis through a key signaling molecule, mammalian target of rapamycin. Thus, we hypothesized that resistance exercise is an important non-pharmacological strategy to counteract deleterious effects of sleep debt on skeletal muscle.

Sleep and muscle recovery: endocrinological and molecular basis for a new and promising hypothesis.

Sleep is essential for the cellular, organic and systemic functions of an organism, with its absence being potentially harmful to health and changing feeding behavior, glucose regulation, blood pressure, cognitive processes and some hormonal axes. Among the hormonal changes, there is an increase in cortisol (humans) and corticosterone (rats) secretion, and a reduction in testosterone and Insulin-like Growth Factor 1, favoring the establishment of a highly proteolytic environment. Consequently, we hypothesized that sleep debt decreases the activity of protein synthesis pathways and increases the activity of degradation pathways, favoring the loss of muscle mass and thus hindering muscle recovery after damage induced by exercise, injuries and certain conditions associated with muscle atrophy, such as sarcopenia and cachexia.

Gender- and age-related variations in blood viscosity in normal volunteers: a study of the effects of extract of Allium sativum and Ginkgo biloba.

This study sought to compare the effects of age and gender on blood viscosity and to appraise the effectiveness of Ginkgo biloba and Allium sativum extracts in reducing blood viscosity. Stage 1: Our sample consisted of 80 male volunteers (40 aged 18-60 and 40 aged 61 and over) and 80 females with the same age profile. Stage 2: We studied 60 male volunteers allocated in groups: placebo, G. biloba, and A. sativum. Stage 3: We studied 25 male volunteers and in the initial, intermediate, and final evaluations, the measures of blood viscosity were repeated. Volunteers were given a clinical evaluation and submitted to laboratory tests. G. biloba led to the highest reduction in blood viscosity compared with placebo and A. sativum. In relation to the use of the two substances, G. biloba and A. sativum, dry extract of G. biloba proved to be more effective in reducing blood viscosity.