Statistical analyses in the physiology of exercise and kinanthropometry

Research into the physiology of exercise and kinanthropometry is intended to improve our understanding of how the body responds and adapts to exercise. If such studies are to be meaningful, they have to be well designed and analysed. Advances in personal computing have made available statistical analyses that were previously the preserve of elaborate mainframe systems and have increased opportunities for investigation. However, the ease with which analyses can be performed can mask underlying philosophical and epistemological shortcomings. The aim of this review is to examine the use of four techniques that are especially relevant to physiological studies: (1) bivariate correlation and linear and non-linear regression, (2) multiple regression, (3) repeated-measures analysis of variance and (4) multi-level modelling. The importance of adhering to underlying statistical assumptions is emphasized and ways to accommodate violations of these assumptions are identified.     

A generalized rank-order method for nonparametric analysis of data from exercise science: a tutorial

Frequent violations of the assumption that data are normally distributed occur in exercise science and other life and behavioral sciences. When this assumption is violated, parametric statistical analyses may be inappropriate for data analysis. We provide a rationale for using a generalized form of nonparametric analyses based on the Puri and Sen (1985) L treated as a chi 2 approximation. If data do not meet the assumption of normality, this nonparametric approach has substantial power and is easy to use. An advantage of this generalized technique is that ranked data may be used in standard parametric statistical programs widely available on desktop and mainframe computers, for example, regression, analysis of variance (ANOVA), multivariate analysis of variance (MANOVA) within BioMed, SAS, SPSS. Once the data are ranked and analyzed with these programs, the only adjustment required is to use a standard formula to calculate the nonparametric test statistic, L, instead of the parametric test statistic (e.g., F). Thus, rank-order nonparametric models become parallel with their parametric counterparts allowing the researcher to select between them based on characteristics of the data distribution. Examples of this approach are provided using data from exercise science for regression, ANOVA (including repeated measures) and MANOVA techniques from SPSSPC. Using these procedures, researchers can easily examine data distributions and make an appropriate decision about parametric or nonparametric analyses while continuing to use their regular statistical packages.     

Central dopaminergic neurotransmission plays an important role in thermoregulation and performance during endurance exercise

Dopamine (DA) has been widely investigated for its potential role in determining exercise performance. It was originally thought that DA's ergogenic effect was by mediating psychological responses. Recently, some studies have also suggested that DA may regulate physiological responses, such as thermoregulation. Hyperthermia has been demonstrated as an important limiting factor during endurance exercise. DA is prominent in the thermoregulatory centre, and changes in DA concentration have been shown to affect core temperature regulation during exercise. Some studies have proposed that DA or DA/noradrenaline (NA) reuptake inhibitors can improve exercise performance, despite hyperthermia during exercise in the heat. DA/NA reuptake inhibitors also increase catecholamine release in the thermoregulatory centre. Intracerebroventricularly injected DA has been shown to improve exercise performance through inhibiting hyperthermia-induced fatigue, even at normal ambient temperatures. Further, caffeine has been reported to increase DA release in the thermoregulatory centre and improves endurance exercise performance despite increased core body temperature. Taken together, DA has been shown to have ergogenic effects and increase heat storage and hyperthermia tolerance. The mechanisms underlying these effects seem to involve limiting/overriding the inhibitory signals from the central nervous system that result in cessation of exercise due to hyperthermia.     

The Use of Structure Coefficients to Address Multicollinearity in Sport and Exercise Science

A common practice in general linear model (GLM) analyses is to interpret regression coefficients (e.g., standardized β weights) as indicators of variable importance. However, focusing solely on standardized beta weights may provide limited or erroneous information. For example, β weights become increasingly unreliable when predictor variables are correlated, which is often the case in the social sciences. To address this issue, structure coefficients, which are simply the bivariate correlation between a predictor and the synthetic ? variable, should also be interpreted. By examining β weights and structure coefficients in conjunction, the predictive worth of each independent variable can be more accurately judged. Despite this benefit, researchers in the field of sport and exercise science have rarely reported structure coefficients when conducting multiple regression analysis. Thus, the purpose of the present article is to discuss problems associated with the sole interpretation of β weights and to demonstrate how structure coefficients can be incorporated to improve accuracy of interpretation. Additionally, a content analysis was conducted to examine current trends in reporting multiple regression results within sport and exercise science research.     

The effects of 15 min and 30 min of exercise on affective responses both during and after exercise

Although much research has examined the relationship between exercise and affect, few studies have considered the effects of exercise bouts of different durations and few researchers have questioned the longer term effects that might be associated with acute exercise. The aim of this study was to compare the effects of the standard health recommended exercise duration of 30 min with a shorter (15 min) bout of exercise upon individuals' affect scores both during and after exercise. Twenty-three (mean age 22.4 years) physically active participants engaged in two counterbalanced cycle ergometer exercise conditions for 15 min (short bout) and 30 min (moderate bout). The participants completed the Subjective Exercise Experience Scale before, during, 5 min, 30 mins, 1 h and 2 h after both exercise conditions. A series of 2 x 6 within-participant repeated-measures analyses of variance for positive well-being (P <0.01), psychological distress (P <0.01) and fatigue (P <0.01) scores revealed significant time main effects, with improved scores over time. No significant differences were noted between the 15-min and 30-min exercise bouts. These results indicate that positive affective responses are experienced by exercisers after relatively short bouts of acute exercise and these effects can still be evident some time later.     

The only constant is change: analysing and understanding change in sport and exercise psychology research

The ability to examine within-person change is essential to test process-based theories in sport and exercise psychology. Longitudinal data, whether experimental or observational, are prerequisites to be able to examine change processes, but most longitudinal studies in sport and exercise psychology focus solely on between-person/group differences, not on within-person change. In this review, we (1) provide researchers in the sport and exercise psychology field with a framework for longitudinal research that focuses on within-person change; (2) provide an overview of how researchers in sport and exercise psychology currently analyse longitudinal data, which showed that most longitudinal studies focus on between-person/group differences; and (3) provide examples of statistical models for analysing longitudinal data that correspond to the framework for longitudinal research. In the examples, we focus on latent variable modelling, such as latent growth-curve modelling and latent change-score modelling, which capture within-person change. We argue that there is a need for stronger emphasis on the match among theory of change, temporal design, and statistical models when designing longitudinal studies in sport and exercise psychology.     

A three-dimensional kinematic analysis of the long jump take-off

The long jump has been widely studied in recent years. Two models exist in the literature which define the relationship between selected variables that affect performance. Both models suggest that the critical phase of the long jump event is the touch-down to take-off phase, as it is in this phase that the necessary vertical velocity is generated. Many three dimensional studies of the long jump exist, but the only studies to have reported detailed data on this phase were two-dimensional in nature. In these, the poor relationships obtained between key variables and performance led to the suggestion that there may be some relevant information in data in the third dimension. The aims of this study were to conduct a three-dimensional analysis of the touch-down to take-off phase in the long jump and to explore the interrelationships between key variables. Fourteen male long jumpers were filmed using three-dimensional methods during the finals of the 1994 (n = 8) and 1995 (n = 6) UK National Championships. Various key variables for the long jump were used in a series of correlational and multiple regression analyses. The relationships between key variables when correlated directly one-to-one were generally poor. However, when analysed using a multiple regression approach, a series of variables was identified which supported the general principles outlined in the two models. These variables could be interpreted in terms of speed, technique and strength. We concluded that in the long jump, variables that are important to performance are interdependent and can only be identified by using appropriate statistical techniques. This has implications for a better understanding of the long jump event and it is likely that this finding can be generalized to other technical sports skills.     

The effects of 15 min and 30 min of exercise on affective responses both during and after exercise

Although much research has examined the relationship between exercise and affect, few studies have considered the effects of exercise bouts of different durations and few researchers have questioned the longer term effects that might be associated with acute exercise. The aim of this study was to compare the effects of the standard health recommended exercise duration of 30?min with a shorter (15?min) bout of exercise upon individuals' affect scores both during and after exercise. Twenty-three (mean age 22.4 years) physically active participants engaged in two counterbalanced cycle ergometer exercise conditions for 15?min (short bout) and 30?min (moderate bout). The participants completed the Subjective Exercise Experience Scale before, during, 5?min, 30 mins, 1?h and 2?h after both exercise conditions. A series of 2 × 6 within-participant repeated-measures analyses of variance for positive well-being (P?<0.01), psychological distress (P?<0.01) and fatigue (P?<0.01) scores revealed significant time main effects, with improved scores over time. No significant differences were noted between the 15-min and 30-min exercise bouts. These results indicate that positive affective responses are experienced by exercisers after relatively short bouts of acute exercise and these effects can still be evident some time later.     

70岁以上老年人体育锻炼与健康体适能相关性研究

为探讨70岁以上老年人体育锻炼等级与健康体适能状况之间的相关性,对365位参与锻炼的70岁以上老年人进行了体育锻炼问卷调查及健康体适能测试,建立了体育锻炼等级与健康体适能线性回归方程模型。结果表明,完成测试的70岁以上老年人中具有规律性体育锻炼习惯的比例较高,其健康体适能总体达到良好水平,回归方程显示体育锻炼等级与健康体适能呈正相关,运动时间与强度能有效预测70岁以上老年人健康体适能状况。提示制定70岁以上老年人运动处方时应以规律性锻炼为基础,可适度提高运动时间与强度,为提高或保持健康体适能水平达到事半功倍之效果。     

A three-dimensional kinematic analysis of the long jump take-off

The long jump has been widely studied in recent years. Two models exist in the literature which define the relationship between selected variables that affect performance. Both models suggest that the critical phase of the long jump event is the touch-down to take-off phase, as it is in this phase that the necessary vertical velocity is generated. Many three dimensional studies of the long jump exist, but the only studies to have reported detailed data on this phase were two-dimensional in nature. In these, the poor relationships obtained between key variables and performance led to the suggestion that there may be some relevant information in data in the third dimension. The aims of this study were to conduct a three-dimensional analysis of the touch-down to take-off phase in the long jump and to explore the interrelationships between key variables. Fourteen male long jumpers were filmed using three-dimensional methods during the finals of the 1994 (n = 8) and 1995 (n = 6) UK National Championships. Various key variables for the long jump were used in a series of correlational and multiple regression analyses. The relationships between key variables when correlated directly one-to-one were generally poor. However, when analysed using a multiple regression approach, a series of variables was identified which supported the general principles outlined in the two models. These variables could be interpreted in terms of speed, technique and strength. We concluded that in the long jump, variables that are important to performance are interdependent and can only be identified by using appropriate statistical techniques. This has implications for a better understanding of the long jump event and it is likely that this finding can be generalized to other technical sports skills.     

Impacts of exercise interventions on different diseases and organ functions in mice

BackgroundIn recent years, much evidence has emerged to indicate that exercise can benefit people when performed properly. This review summarizes the exercise interventions used in studies involving mice as they are related to special diseases or physiological status. To further understand the effects of exercise interventions in treating or preventing diseases, it is important to establish a template for exercise interventions that can be used in future exercise-related studies.MethodsPubMed was used as the data resource for articles. To identify studies related to the effectiveness of exercise interventions for treating various diseases and organ functions in mice, we used the following search language: (exercise [Title] OR training [Title] OR physical activity [Title]) AND (mice [title/abstract] OR mouse [title/abstract] OR mus [title/abstract]). To limit the range of search results, we included 2 filters: one that limited publication dates to “in 10 years” and one that sorted the results as “best match”. Then we grouped the commonly used exercise methods according to their similarities and differences. We then evaluated the effectiveness of the exercise interventions for their impact on diseases and organ functions in 8 different systems.ResultsA total of 331 articles were included in the analysis procedure. The articles were then segmented into 8 systems for which the exercise interventions were used in targeting and treating disorders: motor system (60 studies), metabolic system (45 studies), cardio-cerebral vascular system (58 studies), nervous system (74 studies), immune system (32 studies), respiratory system (7 studies), digestive system (1 study), and the system related to the development of cancer (54 studies). The methods of exercise interventions mainly involved the use of treadmills, voluntary wheel-running, forced wheel-running, swimming, and resistance training. It was found that regardless of the specific exercise method used, most of them demonstrated positive effects on various systemic diseases and organ functions. Most diseases were remitted with exercise regardless of the exercise method used, although some diseases showed the best remission effects when a specific method was used.ConclusionOur review strongly suggests that exercise intervention is a cornerstone in disease prevention and treatment in mice. Because exercise interventions in humans typically focus on chronic diseases, national fitness, and body weight loss, and typically have low intervention compliance rates, it is important to use mice models to investigate the molecular mechanisms underlying the health benefits from exercise interventions in humans.     

Relationship between Physical Fitness and Susceptibility to Cardiovascular Disease

Abstract

This study was conducted (a) to determine through factor analysis techniques the basic factors underlying selected blood variables, metabolic variables, and previously determined physical and athletic fitness variables at four fixed stages of metabolic stress and (b) to determine with the t-test and through discriminant function techniques those blood variables which can discriminate between high and low levels of physical fitness. The objective of the analyses was the interpretation of the revealed information in light of previously found knowledge on the relationship of physical activity and susceptibility to heart disease. Four factors were extracted and interpreted: the effect of weight on motor fitness, the detrimental effect of aging on physical fitness, metabolic readiness, and fitness and NEFA mobility. The t-test showed statistical significance for the difference between the physically fit and unfit group means in resting serum cholesterol, submaximal exercise serum cholesterol, maximal exercise blood pH, and recovery period blood pH. The discriminant function of the combined resting and submaximal exercise serum cholesterol has a statistically determined discriminating power for the physically fit and unfit groups.     

Relationships between exercise regulations and motivational consequences in university students

The aim of this study was to examine propositions stemming from Self-Determination Theory (SDT) that contend motivational consequences vary as a function of different regulations in the exercise domain. Participants (N = 276; n = 98 men; n = 178 women) completed inventories assessing exercise regulations, current exercise behavior, and behavioral intentions to continue exercising for the next 4 months and the effort and importance associated with exercise participation. Bivariate analyses indicated autonomous exercise regulations (identified and intrinsic) were the strongest correlates of each motivational consequence across both sexes, and introjected regulation was positively associated with exercise consequences in women. Simultaneous multiple regression analyses indicated that exercise regulations accounted for a sizeable portion of the variance across each motivational consequence in both sexes (R2adj values ranged from .20 to .53). Both regression and structure coefficients revealed that introjected regulation was a stronger motivational force in women than men, and identified regulation was the most important predictor of all three motivational consequences in both sexes. Collectively, these findings suggest that exercise regulations differentially predict motivational consequences across sexes, and future research using this theoretical framework for examining motivational issues pertinent to the exercise domain appears warranted.     

Animal exercise studies in cardiovascular research: Current knowledge and optimal design—A position paper of the Committee on Cardiac Rehabilitation,Chinese Medical Doctors’ Association

Growing evidence has demonstrated exercise as an effective way to promote cardiovascular health and protect against cardiovascular diseases However, the underlying mechanisms of the beneficial effects of exercise have yet to be elucidated. Animal exercise studies are widely used to investigate the key mechanisms of exercise-induced cardiovascular protection. However, standardized procedures and well-established evaluation indicators for animal exercise models are needed to guide researchers in carrying out effective, high-quality animal studies using exercise to prevent and treat cardiovascular diseases. In our review, we present the commonly used animal exercise models in cardiovascular research and propose a set of standard procedures for exercise training, emphasizing the appropriate measurements and analysis in these chronic exercise models. We also provide recommendations for optimal design of animal exercise studies in cardiovascular research, including the choice of exercise models, control of exercise protocols, exercise at different stages of disease, and other considerations, such as age, sex, and genetic background. We hope that this position paper will promote basic research on exercise-induced cardiovascular protection and pave the way for successful translation of exercise studies from bench to bedside in the prevention and treatment of cardiovascular diseases.     

Animal exercise studies in cardiovascular research: Current knowledge and optimal design—A position paper of the Committee on Cardiac Rehabilitation,Chinese Medical Doctors’ Association

Growing evidence has demonstrated exercise as an effective way to promote cardiovascular health and protect against cardiovascular diseases However, the underlying mechanisms of the beneficial effects of exercise have yet to be elucidated. Animal exercise studies are widely used to investigate the key mechanisms of exercise-induced cardiovascular protection. However, standardized procedures and well-established evaluation indicators for animal exercise models are needed to guide researchers in carrying out effective, high-quality animal studies using exercise to prevent and treat cardiovascular diseases. In our review, we present the commonly used animal exercise models in cardiovascular research and propose a set of standard procedures for exercise training, emphasizing the appropriate measurements and analysis in these chronic exercise models. We also provide recommendations for optimal design of animal exercise studies in cardiovascular research, including the choice of exercise models, control of exercise protocols, exercise at different stages of disease, and other considerations, such as age, sex, and genetic background. We hope that this position paper will promote basic research on exercise-induced cardiovascular protection and pave the way for successful translation of exercise studies from bench to bedside in the prevention and treatment of cardiovascular diseases.     

Exercise immunology: Future directions

Several decades of research in the area of exercise immunology have shown that the immune system is highly responsive to acute and chronic exercise training. Moderate exercise bouts enhance immunosurveillance and when repeated over time mediate multiple health benefits. Most of the studies prior to 2010 relied on a few targeted outcomes related to immune function. During the past decade, technologic advances have created opportunities for a multi-omics and systems biology approach to exercise immunology. This article provides an overview of metabolomics, lipidomics, and proteomics as they pertain to exercise immunology, with a focus on immunometabolism. This review also summarizes how the composition and diversity of the gut microbiota can be influenced by exercise, with applications to human health and immunity. Exercise-induced improvements in immune function may play a critical role in countering immunosenescence and the development of chronic diseases, and emerging omics technologies will more clearly define the underlying mechanisms. This review summarizes what is currently known regarding a multi-omics approach to exercise immunology and provides future directions for investigators.     

Affective–Reflective Theory of physical inactivity and exercise

This article introduces a new theory, the Affective–Reflective Theory (ART) of physical inactivity and exercise. ART aims to explain and predict behavior in situations in which people either remain in a state of physical inactivity or initiate action (exercise). It is a dual-process model and assumes that exercise-related stimuli trigger automatic associations and a resulting automatic affective valuation of exercise (type-1 process). The automatic affective valuation forms the basis for the reflective evaluation (type-2 process), which can follow if self-control resources are available. The automatic affective valuation is connected with an action impulse, whereas the reflective evaluation can result in action plans. The two processes, in constant interaction, direct the individual towards or away from changing behavior. The ART of physical inactivity and exercise predicts that, when there is an affective–reflective discrepancy and self-control resources are low, behavior is more likely to be governed by the affective type-1 process. This introductory article explains the underlying concepts and main theoretical roots from which the ART of physical inactivity and exercise was developed (field theory, affective responses to exercise, automatic evaluation, evaluation-behavior link, dual-process theorizing). We also summarize the empirical tests that have been conducted to refine the theory in its present form.     

学龄前儿童基本动作技能干预研究的Meta分析

目的:系统评价近十年内应用粗大动作发展测试(TGMD)的国内外学龄前儿童运动干预后的基本动作技能(FMS),包括位移技能(LMS)和物体控制技能(OC)。方法:通过Web of Science、PubMed、中国知网数据库检索2010年1月1日至2021年2月25日学龄前儿童基本动作技能干预的相关中英文文献,由2名作者对文献进行筛选、数据提取、质量评估,采用Review Manager 5.3软件进行Meta分析与敏感性分析,采用Stata13.0软件进行Meta回归分析与发表偏倚,共纳入15项研究,包括干预组893例、对照组687例。Meta分析结果显示:运动干预对提高学龄前儿童位移技能和物体控制技能均具有显著影响。亚组分析结果显示:运动干预周期为5~15周、干预频率为2~3次/周、干预时间为20~50 min,采用结构化运动课程的干预效果良好。Meta回归分析结果显示:运动干预总时间对学龄前儿童LMS具有负向影响且差异具有显著性,表明随运动干预总时间的增加,干预效果降低。结论:运动干预对于提高学龄前儿童基本动作技能具有显著作用。建议后续研究对运动干预进行合理的控制和评估,进一步探索有效运动干预的关键特征。     

青少年体育锻炼中的同伴效应及性别差异

基于“中国教育追踪调查”(CEPS)数据,通过描述性统计分析、相关分析、构建最小二乘线性(OLS)回归模型、系数集束化分析等方法,分析同伴群体对我国青少年体育锻炼的影响,结果显示:①青少年体育锻炼中存在很强的同伴效应,该效应约为个体影响的80%,并大大超过家庭、班级和学校的影响;②同伴群体对青少年体育锻炼时间的影响具有明显的性别差异,是男生体育锻炼时间的最强影响因素,但对女生体育锻炼时间的影响弱于个体、班级和学校效应;③异性好友对青少年、特别是男生体育锻炼时间的提升作用更大,对女生而言,独生子女相对非独生子女的体育锻炼时间显著增加。提出:相关青少年体育锻炼促进计划应充分考虑以上因素,通过对同伴群体的干预提升青少年身体活动水平。     

Resistance training and older adults' beliefs about psychological benefits: the importance of self-efficacy and social interaction

The purpose of this study was to determine the perceived psychological benefits and explore the mechanisms underlying the link between exercise and psychological well-being for a group of older adults (65-72 years; 6 women; 4 men) who participated in a 12-week program of moderate-to-high intensity resistance training. They were interviewed in-depth at 1 week preintervention, 1 month after commencement, and 1 week after completion. The participants believed that resistance training enhanced their well-being, and they gave various physical, mental, and social reasons to explain this link. In particular, self-efficacy and social interaction were found to be key mechanisms underlying this relationship. This study exposed meaningful perceived improvements in psychological wellbeing that have not been uncovered in quantitative studies of healthy older people undertaking resistance training. The findings highlight the importance of using qualitative methods to enrich understandings of the positive effect of exercise on psychological well-being. The findings also have implications for designing effective resistance training interventions for older people.