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.

Acute physical exercise under hypoxia improves sleep, mood and reaction time.

This study aimed to assess the effect of two sessions of acute physical exercise at 50% VO2peak performed under hypoxia (equivalent to an altitude of 4500 m for 28 h) on sleep, mood and reaction time. Forty healthy men were randomized into 4 groups: Normoxia (NG) (n = 10); Hypoxia (HG) (n = 10); Exercise under Normoxia (ENG) (n = 10); and Exercise under Hypoxia (EHG) (n = 10). All mood and reaction time assessments were performed 40 min after awakening. Sleep was reassessed on the first day at 14 h after the initiation of hypoxia; mood and reaction time were measured 28 h later. Two sessions of acute physical exercise at 50% VO2peak were performed for 60 min on the first and second days after 3 and 27 h, respectively, after starting to hypoxia. Improved sleep efficiency, stage N3 and REM sleep and reduced wake after sleep onset were observed under hypoxia after acute physical exercise. Tension, anger, depressed mood, vigor and reaction time scores improved after exercise under hypoxia. We conclude that hypoxia impairs sleep, reaction time and mood. Acute physical exercise at 50% VO2peak under hypoxia improves sleep efficiency, reversing the aspects that had been adversely affected under hypoxia, possibly contributing to improved mood and reaction time.

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.

Perception of family support in dependents of alcohol and others drugs: relationship with mental disorders.

The present article aimed to analyze the relationships between perception of family support, levels of depression, anxiety and hopelessness in alcohol or drug dependent patients (AOD). Participated of this study 97 patients under treatment, aged between 18 and 58 years, of both genders from six private institutions for treatment of drug dependency, located in Santos-SP/Brazil. Participants responded to the Inventory of Perceived Family Support-IPSF, the Beck Depression Inventory-BDI, Beck Anxiety Inventory-BAI, Hopelessness Scale-BHS and Criteria for substance abuse or dependence at DSM-IV TR. Results indicated negative correlations between perceived family support and levels of depression, anxiety and hopelessness. Moreover, family support proved to be a conditional variable for levels of anxiety and depression. These results indicated that the perception of family support may be an important social support for the patient with AOD.

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.

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.