Do 5% changes around maximal lactate steady state lead to swimming biophysical modifications?

Our purpose was to examine the swimming biophysical responses at velocities (v) of 97.5, 100 and 102.5% of the maximal lactate steady state (MLSS). Ten elite female swimmers performed three-to-five 30-min constant tests at imposed paces to determine 97.5, 100 and 102.5%MLSS v. Gas exchange, blood lactate concentration ([La-]), stroke rate (SR) and v were determined during each test. The v values at 97.5, 100 and 102.5%MLSS were 1.21 ± 0.07, 1.24 ± 0.07 and 1.27 ± 0.07 m.s⁻¹, respectively. Oxygen uptake (V̇O₂) and Pulmonary ventilation (V̇E) increased as function of v. SR and stroke length (v/SR = SL) increased as a function of v. All measured variables were constant as a function of time at 97.5%MLSS and 100%MLSS. At 102.5%MLSS SR increased (3.5%) and stroke length (SL) decreased (3.5%) as a function of time. While V̇O₂ was constant at 102.5%MLSS, [La-] and V̇E increased as a function of time, suggesting hyperventilation, at v’s of 97.5%MLSS and 100%MLSS swimmers completed the 30 min swim in spite of decreased SL and increased SR. However, the decrease in SL and increased SF were accompanied by increased [La-] and V̇E and resulted in the inability of most swimmers to complete the 30 min swim presumably due to fatigue at 102.5%MLSS.     

The systematic identification of content and delivery style of an exercise intervention

Objective: This study explored the utility of using behaviour change taxonomies and checklists to systematically assess the content and delivery of behavioural support for physical activity delivered through an established exercise-referral scheme.

Design: An observation study was conducted whereby 22% of initial consultations were observed and audio-recorded, using quota sampling stratified by exercise-referral advisor.

Main outcome measures: Content was independently coded by two researchers, to assess; (i) completeness in delivering the programme protocol, (ii) behaviour change techniques delivered (defined using the CALO-RE taxonomy) and (iii) delivery style according to the Behaviour Change Counselling Index (BECCI).

Results: Protocol completeness was 63.6% (range 35.6–74.6%). The behaviour change techniques delivered most consistently were ‘providing information about where and when to perform the behavior’ (86%) and ‘setting outcome goals’ (82%). Other evidence-based techniques such as self-monitoring were infrequently observed. Variation in BECCI scores indicated that advisors could, but did not consistently, provide a client-centred service.

Conclusion: This study highlights how theoretically informed taxonomies can be useful in evaluating service delivery within applied practice, providing a meaningful way of assessing the completeness of protocol delivery relative to evidence. The provision of feedback to practitioners based on such objective criteria also facilitated positive academic-practitioner communication.     

Personality traits and body mass index: Modifiers and mechanisms

Objective: To identify how demographic factors (sex, age, ethnicity) modify the association between personality traits and body mass index (BMI) and to test the extent that diet and physical activity account for the personality-BMI relations.

Design: Cross-sectional study with a diverse sample (N = 5150, 50% female, 19% African American, 15% Hispanic). Participants completed a measure of the five major dimensions of personality and reported on their physical activity, diet and food intake behaviour, and height and weight.

Main Outcome Measures: BMI and obesity (BMI ≥ 30).

Results: High Neuroticism was associated with higher BMI and risk for obesity, whereas Conscientiousness and, to a lesser extent, Extraversion and Openness were protective. These associations were generally stronger among women and older participants; there was less evidence for ethnicity as a moderator. Personality had similar relations with the behavioural factors, and physical activity, diet and regular meal rhythms accounted for approximately 50% of the association between Neuroticism and Conscientiousness and BMI.

Conclusion: This study supports the links between personality traits and BMI and suggests that physical activity, more than diet, is a key factor in these associations.     

Links between religiously-focused exercise and body shape preoccupation among young adults

This quasi-experimental study examined whether engaging in physical exercise integrated with a Christian religious focus would result in decreased body shape preoccupation and improved mental and emotional health. Data were collected at the beginning and end of an eight-week period from female and male college students in three conditions: (1) group exercise sessions integrating an explicit religious focus, (2) standard group exercise, and (3) a control condition without activities. The religious exercise group decreased in body shape preoccupation to a greater extent than the control group, but the groups did not differ in other psychological symptoms or affect. This offers an initial indication that integrating a religious focus with exercise may potentially offer a unique method for addressing body shape preoccupation that is not accounted for by improvements in mental health or affect. If confirmed through additional research, infusing a religious focus into exercise regimens might inspire a practical, inexpensive method of targeting body shape dissatisfaction among young adults.     

The effects of aerobic exercise on working memory in methamphetamine-dependent patients: Evidence from combined fNIRS and ERP

ObjectiveTo explore the effect of aerobic exercise on working memory according to exercise intensity in patients with methamphetamine (MA) dependence.DesignTwelve-week randomized controlled trial.MethodForty-five MA-dependent patients were divided randomly into three groups participating in 12-week moderate- and high-intensity aerobic exercise interventions and no intervention (control), respectively. Working memory performance was assessed using a 2-back task, and a combined functional near-infrared spectral imaging–event-related potential measure was used to identify spatial and temporal components of the neurofunctional underpinnings of this performance.ResultsHigh-intensity exercise significantly enhanced the discernment aspect of working memory. It also decreased N1 and P2 amplitudes, and increased neural activity in the left dorsolateral prefrontal cortex.ConclusionsThe findings of this study suggest that high-intensity aerobic exercise can enhance working memory and neural activity in MA-dependent patients, and thus that it may serve as an effective therapeutic tool for these patients.     

Dancing with passion: A look at interpersonal relationships

Drawing from the dualistic model of passion for activities (Vallerand et al., 2003), this research investigated the role of passion for social partnered dancing in relationships quality with other dancers as well as outside of the dance community, in a romantic relationship. Study 1 showed that harmonious passion (HP) was related to enjoyment while dancing with a novice partner, whereas obsessive passion (OP) was associated with negative interactions with an incompetent partner. Study 2 showed that HP was positively related to relationship quality with a preferred dance partner and the dance community through mastery-approach and social connection goals, whereas the opposite effect characterized OP. Also, OP was negatively related to relationship quality with both a dance partner and a romantic partner through conflict, whereas the reverse trend characterized HP. This research identified mechanisms through which passion may affect relationships within and outside a passionate activity such as dance.     

身体活动的双系统理论:一种强化学习的视角

以理性决策为基础的锻炼行为理论被认为是理解身体活动的主导体系, 它提供了与身体活动相关的认知构念作为有价值的信息。基于社会生态模型设计的行为干预措施, 因表现出了更好的效果而备受关注。近期研究表明, 积极的运动认知和当前体育环境都没能很好地促进个人锻炼习惯的养成, 因此有必要探索新的理论体系来阐明个人锻炼习惯的形成机制。解释身体活动的最新体系是双系统理论, 由于其考虑了身体活动的无意识和快乐决定因素, 有望提供一个更广泛的动机视角。一方面, 多个有代表性的身体活动双系统模型, 从简单的自发路径, 到情境线索与锻炼习惯, 再到突出自动情感评价作用的复杂概念模型, 阐明了系统1的构建, 结合锻炼行为理论所关注的系统2, 为模型的构建提供了依据。另一方面, 通过对双系统的竞争、协调和层级控制原则的分析, 为模型的控制提供了建议。经典的强化学习框架解释了双系统模型的构建与控制原则:在模型的构建方面, 无模型与基于模型的强化学习分别表示系统1和系统2。在模型的控制方面, Dyna协作架构与分层强化学习, 为身体活动可能是一种相互协作、分层执行的复杂行动组合提供了合理解释。最后提出强化学习视角下锻炼者-体育环境的互动模式, 试图从一个全新的角度探讨锻炼行为。     

运动习惯与社区老年人认知功能的关系

为评估社区老年人运动习惯与认知功能的关系,在北京市通过分层、方便取样的方法选取60岁以上的老年人732名,采用自编调查表收集一般人口学资料及运动习惯情况（包括有无运动习惯,运动频率,运动持续时间）,使用简明精神状态评估量表（MMSE）和北京版蒙特利尔认知评估量表（MoCA-BJ）评估认知功能。结果发现：（1）运动组整体认知功能及视空间定向能力得分均高于无运动组;（2）有无运动习惯可正向预测整体认知功能及视空间定向能力得分;（3）运动持续10年及以上组整体认知功能得分高于运动持续10年以下组。结果表明：相对于无运动习惯的社区老年人,有运动习惯的社区老年人的整体认知功能及视空间定向能力更好;运动持续年数较长,对社区老年人的认知功能起到促进作用。     

孟子德性论的思维理路与儒家哲学认识和把握世界的基本方式

从性、天统一的德性论,到“德教”、“成德”的德性生成论,再到以德行仁的仁政学说,呈现出了孟子道德形上学的基本理路和环节。这一思维理路反映了中国哲学、尤其是儒家哲学认识和把握世界的基本方式。     

Brief Report: Self-Objectification and Esteem in Young Women: The Mediating Role of Reasons for Exercise

In this study we investigated the interrelationships between self-objectification, reasons for exercise, body satisfaction, body esteem, and self-esteem. A questionnaire that assessed each of these constructs was completed by 104 female participants between the ages of 16 and 25 who exercised regularly at a fitness center. Self-objectification and appearance-related reasons for exercise were significantly negatively related to body satisfaction, body esteem, and self-esteem, and functional reasons for exercise were positively related to each of these outcome measures. Self-objectification also predicted the reasons women exercise. More important, reasons for exercise were found to mediate the relationships between self-objectification and body satisfaction, body esteem, and self-esteem. It was concluded that objectification theory can be extended usefully into the realm of exercise and that, among women who exercise, motivations for exercise account for the reduced body satisfaction and self-esteem for women high on self-objectification.