Valdir de Aquino Lemos

High altitude exposure impairs sleep patterns, mood, and cognitive functions

This work evaluated the importance of sleep on mood and cognition after 24 h of exposure to hypoxia. Ten males, aged 23-30 years, were placed in a normobaric chamber simulating an altitude of 4,500 m. Sleep assessments were conducted from 22:00-6:00; all mood and cognitive assessments were performed 20 min after awakening. The assessments were conducted in normoxic conditions and after 24 h of hypoxia. Sleep was reevaluated 14 h after the start of exposure to hypoxic conditions, and mood state and cognitive functions were reevaluated 24 h after the start of exposure to hypoxic conditions. Hypoxia reduced total sleep time, sleep efficiency, slow-wave sleep, and rapid eye movement. Depressive mood, anger, and fatigue increased under hypoxic conditions. Vigor, attention, visual and working memory, concentration, executive functions, inhibitory control, and speed of mental processing worsened. Changes in sleep patterns can modulate mood and cognition after 24 h.

Relationship between physical activity and depression and anxiety symptoms: A population study

BACKGROUND There are few studies evaluating the association between practice of physical activity and mood in a population sample. This study evaluated the frequency of symptoms of depression and anxiety in the population of the city of Sao Paulo and their association with the report of practice of regular physical activity. METHODS This survey was conducted with the adult population of Sao Paulo between July and December of 2007. The sample was composed of 1042 volunteers (both genders) with a mean age of 41.9±14.4 years. The volunteers were evaluated using the Beck Depression Inventory, the Beck Anxiety Inventory, and two simple questions designed to evaluate and classify physical activity. Socioeconomic status was also determined according to Brazils Economic Classification Criterion. RESULTS People who do not engage in physical activity are two times more likely to exhibit symptoms of depression (PR: 2.1) and anxiety (PR: 2.5) compared with those who regularly practice physical activity and a higher prevalence of symptoms for anxiety (9.8%) and depression (10.9%) was observed among those claiming to not practice regular physical activity and 63.2% related did not practice any physical activity regularly. CONCLUSION Altogether, these results suggest that people who do not practice physical activity have a higher chance of exhibiting symptoms of depression and anxiety when compared to those who perform physical activity regularly. In this sense, regular physical activity must be encouraged, and this incentive should be routine in both current and future public health policies. Although the methodology in the present study does not allow assigning a relation of cause and effect, we observed associations between symptoms of depression, anxiety and physical activity.

Low-Grade Inflammation and Spinal Cord Injury: Exercise as Therapy?

An increase in the prevalence of obesity in people with spinal cord injury can contribute to low-grade chronic inflammation and increase the risk of infection in this population. A decrease in sympathetic activity contributes to immunosuppression due to the lower activation of immune cells in the blood. The effects of physical exercise on inflammatory parameters in individuals with spinal cord injury have not been well described. We conducted a review of the literature published from 1974 to 2012. This review explored the relationships between low-grade inflammation, spinal cord injury, and exercise to discuss a novel mechanism that might explain the beneficial effects of exercise involving an increase in catecholamines and cytokines in people with spinal cord injury.

Aerobic Physical Exercise Improved the Cognitive Function of Elderly Males but Did Not Modify Their Blood Homocysteine Levels

Background: Physical exercise influences homocysteine (Hcy) concentrations, cognitive function and the metabolic profile. The purpose of this study was to investigate the influence of regular physical exercise on Hcy levels, the metabolic profile and cognitive function in healthy elderly males before and after an endurance exercise program. Methods: Forty-five healthy and sedentary volunteers were randomized into 2 groups: (1) a control group asked not to change their normal everyday activities and not to start any regular physical exercise program and (2) an experimental group trained at a heart rate intensity corresponding to ventilatory threshold 1 (VT-1) for 60 min/day 3 times weekly on alternate days for 6 months using a cycle ergometer. All volunteers underwent cognitive evaluations, blood sample analyses and ergospirometric assessments. Results: A significant improvement in cognitive function was observed in the experimental group compared with the control group (p < 0.05). No significant changes in Hcy levels were observed in the experimental group (p > 0.05), but there was a significant increase in peak oxygen consumption and workload at VT-1 as well as a significant improvement in cholesterol, triglycerides, HDL, glucose, alkaline phosphatase, urea, T3, T4 and prostate-specific antigen compared with the control group (p < 0.05). Conclusion: The data suggest that a physical exercise program does not reduce Hcy levels in healthy elderly males, although it improves the cardiovascular and metabolic profile as well as cognitive function.

Can High Altitude Influence Cytokines and Sleep

The number of persons who relocate to regions of high altitude for work, pleasure, sport, or residence increases every year. It is known that the reduced supply of oxygen (O2) induced by acute or chronic increases in altitude stimulates the body to adapt to new metabolic challenges imposed by hypoxia. Sleep can suffer partial fragmentation because of the exposure to high altitudes, and these changes have been described as one of the responsible factors for the many consequences at high altitudes. We conducted a review of the literature during the period from 1987 to 2012. This work explored the relationships among inflammation, hypoxia and sleep in the period of adaptation and examined a novel mechanism that might explain the harmful effects of altitude on sleep, involving increased Interleukin-1 beta (IL-1β), Interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) production from several tissues and cells, such as leukocytes and cells from skeletal muscle and brain.

Motivational and evolutionary aspects of a physical exercise training program: a longitudinal study.

Several studies have indicated that motivational level and prior expectations influence one’s commitment to physical activity. Moreover, these aspects are not properly described in terms of proximal (SDT, Self Determination Theory) and distal (evolutionary) explanations in the literature. This paper aims to verify if level of motivation (BREQ-2, Behavioral Regulation in Exercise Questionnaire-2) and expectations regarding regular physical exercise (IMPRAF-54) before starting a 1-year exercise program could determine likelihood of completion. Ninety-four volunteers (53 women) included a completed protocol group (CPG; n = 21) and drop-out group (n = 73). The IMPRAF-54 scale was used to assess six different expectations associated with physical activity, and the BREQ-2 inventory was used to assess the level of motivation in five steps (from amotivation to intrinsic motivation). Both questionnaires were assessed before starting a regular exercise program. The CPG group presented higher sociability and lower pleasure scores according to IMPRAF-54 domains. A logistic regression analysis showed that a one-point increment on sociability score increased the chance of completing the program by 10%, and the same one-point increment on pleasure score reduced the chance of completing the protocol by 16%. ROC curves were also calculated to establish IMPRAF-54 cutoffs for adherence (Sociability – 18.5 points – 81% sensibility/50% specificity) and dropout (Pleasure – 25.5 points – 86% sensibility/20% specificity) of the exercise protocol. Our results indicate that an expectation of social interaction was a positive factor in predicting adherence to exercise. Grounded in SDT and its innate needs (competence, autonomy, relatedness), physical exercise is not an end; it is a means to achieve autonomy and self-cohesion. The association of physical activity with social practices, as occurs in hunter-gathering groups, can engage people to be physically active and can provide better results in adherence exercise programs for the general population.

Suporte familiar, crenças irracionais e sintomatologia depressiva em estudantes universitários

The present study aimed to verify the relations between the perception of family support, depressive symptoms and irrational beliefs. The sample included 377 volunteers of a university of Sao Paulo with mean age of 20,69 years (SD= 2,29) and with a prevalence of women (68,2%), that answered to the Inventario de Percepcao de Suporte Familiar - IPSF, the Inventario de Depressao de Beck-BDI and the Escala de Crencas Irracionais - ECI. The results showed correlations between the IPSF with BDI and ECI, indicating that higher scores on the perception of family support implied less depressive symptoms and lower number of irrational beliefs of the subjects. Correlations between BDI and ECI were also found, indicating that highest scores on irrational beliefs indicated higher scores on depression symptoms, according to the literature.

Assessment of Body Composition and Sport Performance of Brazilian Paralympic Swim Team Athletes

CONTEXT Body-composition assessments of high-performance athletes are very important for identifying physical performance potential. Although the relationship between the kinanthropometric characteristics and performance abilities of Olympic swimmers is extremely important, this subject is not completely understood for Paralympic swimmers. OBJECTIVE To investigate the relationship between body composition and sport performance in Brazilian Paralympic swimmers 6 mo after training. DESIGN Experimental pre/posttest design. SETTING Research laboratory and field evaluations of swimming were conducted to verify the 50-m freestyle time of each athlete. PARTICIPANTS 17 Brazilian Paralympic swim team athletes (12 men, 5 women). MAIN OUTCOME MEASURES Body-composition assessments were performed using a BOD POD, and swimming performance was assessed using the 50-m freestyle, which was performed twice: before and after 6 mo of training. RESULTS Increased lean mass and significantly reduced relative fat mass and swimming time (P < .05) were observed 6 mo after training. Furthermore, a positive correlation between body-fat percentage and performance (r = .66, P < .05) was observed, but there was no significant correlation between body density and performance (r = -.14, P > .05). CONCLUSIONS After a 6-mo training period, Paralympic swimmers presented reduced fat mass and increased lean body mass associated with performance, as measured by 50-m freestyle time. These data suggest that reduced fat-mass percentage was significantly correlated with improved swimming performance in Paralympic athletes.

Melatonin and sleep responses to normobaric hypoxia and aerobic physical exercise: A randomized controlled trial

This work evaluated the effects of moderate physical exercise performed under hypoxic conditions on melatonin and sleep. Forty healthy men were randomized into four groups: Normoxia (N) (n = 10); Hypoxia (H) (n = 10); Exercise under Normoxia (EN) (n = 10); and Exercise under Hypoxia (EH) (n = 10). The observation period for all groups was approximately 36 h, beginning with a first night devoid of any intervention. Aerobic exercise was performed by the EN and EH groups on a treadmill at 50% of the ventilatory threshold intensity for 60 min. Sleep evaluation was performed on the 1st and 2nd nights. Venous blood samples for the melatonin measurement were obtained on the 1st and 2nd days at 7:30 AM as well as on the 1st and 2nd nights at 10:30 PM. On the 2nd night, melatonin was higher in the H group than in the N group, but both were lower than values of the EH group. The nocturnal increase in melatonin was inversely correlated with the oxygen saturation of hemoglobin (SaO2%) on the 2nd night in the H group and on the 2nd day in the EH group. Diurnal remission of nocturnal melatonin appeared to be postponed in the H group and even more so in the EH group. Thus, normobaric hypoxia, which is equivalent to oxygen availability at an altitude of 4500 m, acutely increases melatonin. Moreover, diurnal remission of the nocturnal increase in melatonin seems to be delayed by hypoxia alone but even more so when acting together with exercise.

Analysis of the body composition of Paralympic athletes: Comparison of two methods

Abstract Body composition is a physiological variable associated with physical activity and, in some cases, is related to athletic performance. Our objectives were to describe the body composition of participants in three distinct Paralympic sports and to compare the values of body density and estimated body fat obtained from the Paralympic athletes on the National Team by air-displacement plethysmography (ADP) and by the anthropometric method (skinfolds (SFs)). The sample consisted of 70 volunteers of both genders. The body composition of the volunteers was evaluated using the ADP in a Bod Pod® and seven SFs. There were no significant differences between the values obtained by ADP and SF for body fat percentage (p = .58) and body density (p = .49). Analysis by Bland–Altman plots showed mean differences of 0.56 ± 4.94 (−9.12–10.23) and −0.0017 ± 0.0113 (−0.024–0.020) for body fat percentage and body density, respectively. In conclusion, body composition analyses of Paralympic athletes by the ADP and SF methods show similar results, and ADP should be used as the first option when available. When the use of ADP is not possible, estimating body density and fat percentage by SF is a viable alternative for Paralympic athletes when future comparisons will use the same analysis method.