Effect of bright light therapy on delayed sleep/wake cycle and reaction time of athletes participating in the Rio 2016 Olympic Games.

This study investigated the effect of using an artificial bright light on the entrainment of the sleep/wake cycle as well as the reaction times of athletes before the Rio 2016 Olympic Games. A total of 22 athletes from the Brazilian Olympic Swimming Team were evaluated, with the aim of preparing them to compete at a time when they would normally be about to go to bed for the night. During the 8-day acclimatization period, their sleep/wake cycles were assessed by actigraphy, with all the athletes being treated with artificial light therapy for between 30 and 45 min (starting at day 3). In addition, other recommendations to improve sleep hygiene were made to the athletes. In order to assess reaction times, the Psychomotor Vigilance Test was performed before (day 1) and after (day 8) the bright light therapy. As a result of the intervention, the athletes slept later on the third (p = 0.01), seventh (p = 0.01) and eighth (p = 0.01) days after starting bright light therapy. Regarding reaction times, when tested in the morning the athletes showed improved average (p = 0.01) and minimum reaction time (p = 0.03) when comparing day 8 to day 1. When tested in the evening, they showed improved average (p = 0.04), minimum (p = 0.03) and maximum reaction time (p = 0.02) when comparing day 8 to day 1. Light therapy treatment delayed the sleep/wake cycles and improved reaction times of members of the swimming team. The use of bright light therapy was shown to be effective in modulating the sleep/wake cycles of athletes who had to perform in competitions that took place late at night.

Load Monitoring Variables in Training and Competition Situations: A Systematic Review Applied to Wheelchair Sports.

The aim of this review was to identify the main variables for load monitoring in training and competition situations in wheelchair sports. Studies were identified from a systematic search of three databases (PubMed, Web of Science, and SportDiscuss), with search phrases constructed from MeSH terms, alone or in combination, limited to English-language literature, and published up to January 2016. Our main findings were that variables related to external load (distance, speed, and duration) are used to monitor load in competition. In training situations, researchers have used variables related to internal load (heart rate and VO2); in both training and competition situations, researchers used internal load measurements (training impulse and ratings of perceived exertion). We conclude that the main variables for load monitoring in competitive situations were distance, speed, and duration, whereas the variables for training situations were heart rate, VO2, training impulse, and ratings of perceived exertion.

2016 Rio Olympic Games: Can the schedule of events compromise athletes' performance?

The organizing committee of the 2016 Rio Olympic Games recently announced that some of the preliminary and final competitions will be held at night. The present article discusses the potential harmful effects of these late-night competitions on sleep, circadian rhythms and athletic performance during the Olympic Games. Specifically, night-time competition could lead to injury and may compromise an athlete's decision-making, attentional, physiological and other processes. Consequently, these impacts could negatively affect the performance of athletes and their teams. Thus, it is suggested that technical commissions take special care when creating strategies to minimize harm to the athletes by considering factors such as light exposure, melatonin intake, sleep hygiene and scheduled naps, and training at local competition time. Furthermore, it is necessary for specialists in chronobiology and sleep to engage with members of the national teams to develop an activity schedule for physical, technical, tactical and psychological preparation that accounts for circadian rhythms, thereby creating the best possible environment for the athletes to achieve their ideal performance.

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.