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.     

锻炼心理学视野下运动干预大学生网络成瘾的可行性分析

采用文献资料法、逻辑分析法对大学生网络成瘾的机制进行分析,认为大学生网络成瘾是由生理—心理—环境共同交互、相互渗透、相互作用下形成的。体育锻炼在网络成瘾机制的各个层面上都有其干预的途径,应加强对网络成瘾机制及干预手段的多元化的研究,以期为大学生网络成瘾找到有效的防治途径。     

Social support and physical activity participation among healthy adults: a systematic review of prospective studies

The objective of this review was to determine the direction and strength of the prospective relationship between social support and PA among healthy adults. A systematic review was conducted; including studies up until December 2015, in the following databases: Ovid MEDLINE, EMBASE, PsychINFO, SPORTDiscus, and Scopus. Published English and French written studies were included if the reported study used a longitudinal design; examined the relationship between social support and PA over at least two intervals; and assessed a sample of healthy adults between 18–65 years of age. Two reviewers independently extracted study information and independently assessed the risk of bias in each study. The initial search yielded a total of 2892 citations, and 20 studies were included in the review. Follow-up period ranged from 2 weeks to 10 years. Irrespective of the type and source of support, the strength and direction of the association between social support and PA was inconsistent across studies, with effect sizes ranging from small to large and from negative to positive. Based on meta-analysis, there was a small positive association between support for PA from friends and future PA. Researchers are encouraged to continue to conduct longitudinal studies to better understand the relationship between social support and PA.     

Being and feeling addicted to exercise: Reflections from a neophenomenological perspective

Since its emergence during the 1970s, scientific research on exercise addiction has been interested primarily in the mental and physical causes and consequences of the behaviour of exercise addicts. This focus can be ascribed to the dominance of psychology and medicine among this field of research. This paper wishes to contribute to these thematic priorities and basic approaches by taking a phenomenological perspective as a basis, thus making the embodied and the personal dimension of exercise addiction the centre of attention. This approach aims towards two goals: First, it shall be pointed out that philosophy, especially phenomenology, can make a profound contribution to research concerning exercise addiction. Second, a phenomenological approach, which has so far remained mostly unknown to international sport philosophy, will be introduced, namely the New Phenomenology founded by German philosopher Hermann Schmitz. For this purpose, the objective of New Phenomenology will be explained as well as its two pivotal terms ‘felt body’ and ‘person’. Based on this, the main features of a neophenomenological analysis of exercise addiction that puts a focus on embodied experience and one’s personal situation will be outlined. Lastly, the analytical potential of New Phenomenology will be elucidated by means of an empirical case analysis.     

Sex differences in injury rates in team-sport athletes: A systematic review and meta-regression analysis

Background:Team-sport players have a particularly high injury risk.Although female sex is considered a risk factor,it is still unknown whether female and male team-sport players,in fact,differ in their injury rates.We aimed to compare injury rates between female and male players by systematically reviewing and meta-analyzing injury surveillance studies of both sexes in order to evaluate sex-specific differences in team-sport injuries.Methods:Studies that prospectively collected injury data for high-level female and male players(age≥16 years)in basketball,field hockey,football(soccer),handball,rugby(union and sevens),and volleyball were included.Two reviewers(AZ and ALR)independently assessed study quality and extracted data for overall,match,training,and severe injuries(>28 days’time loss)as well as data regarding injury locations and types.Incidence rate ratios(IRRs)were pooled in a meta-analysis,and meta-regression analysis was performed when 10 or more studies were available.Results:Of 20 studies,9 studies reported injury data from football,3 studies from rugby,3 studies from handball,1 study from basketball,1 study from field hockey,2 studies from volleyball,and 1 study from basketball and field hockey.For overall injuries,the pooled IRR=0.86(95%confidence interval(95%CI):0.76-0.98)indicated significantly more injuries in male than in female players.For injury location,the pooled IRR showed higher injury rates in male athletes than in female athletes for upper extremity,hip/groin,thigh,ande foot injuries.Female players had a significantly higher rate of anterior cruciate ligament injuries(IRR=2.15,95%CI:1.27-3.62)than male players.No significant sex-specific differences in IRR were found for match,training,severe injuries,concussions,or ankle sprains.Conclusion:Our meta-analysis provides evidence for sex-specific differences in the injury rates in team sports.Further epidemiological studies including both sexes in sports other than football are needed in order to strengthen the evidence.     

Organismic integration as a dynamic process: a systematic review of empirical studies on change in behavioral regulations in exercise in adults

In facilitating the adoption of exercise behavior, attention should be directed towards the dynamic nature of behavioral regulations. Organismic integration theory presents a suitable framework for investigating fluctuations in behavioral regulations. However, current results pertaining to this issue revealed mixed findings. The aim of this review is to examine the empirical literature on the dynamic nature of organismic integration theory in exercise settings over time in adults. A systematic review of English articles using PsycINFO, PsycARTICLES, ScienceDirect, and SPORTDiscus was conducted including keywords of organismic integration theory, longitudinal designs, change in behavioral regulations, and exercise. Findings are summarized through quantitative analysis of the evidence. Regarding autonomous regulations, steady increases in regulations are observable that originate within the first weeks and persist for up to one year. Most studies reported no changes in controlled regulations, although in a few cases changes were observed six weeks after baseline or later. The review adds to the theoretical understanding of how behavioral regulations are internalized. However, whether changes in regulation occur depends on both the type of regulation and on contextual characteristics. Future research of longitudinal design is warranted to identify optimal periods in which individuals seek for increased support during exercise adoption.     

锻炼行为和锻炼动机的性别差异——以高知人员为例的比较研究

对590名高级知识分子作问卷调查,对比分析了两性的健康状况、体育行为和锻炼动机。结果表明：①与男性相比,女性高知人员每次锻炼的时间短,锻炼强度小,两性体育锻炼频率和锻炼坚持差异不显著;②女性高知人员的外貌动机和乐趣动机明显强于男性,是她们参与体育锻炼的主要心理动力,这样的锻炼动机模式使她们选择参与轻松、对抗小和娱乐性强的体育锻炼项目;③高知人员健康状况不存在显著性性别差异,锻炼行为和动机存在的差异符合女性的身心特点,反映出在高知人员中性别平等程度较高。     

Inter-individual differences in the responses to aerobic exercise in Alzheimer’s disease: Findings from the FIT-AD trial

Background:Despite the strong evidence of aerobic exercise as a disease-modifying treatment for Alzheimer’s disease(AD)in animal models,its effects on cognition are inconsistent in human studies.A major contributor to these findings is inter-individual differences in the responses to aerobic exercise,which was well documented in the general population but not in those with AD.The purpose of this study was to examine inter-individual differences in aerobic fitness and cognitive responses to a 6-month aerobic exercise intervention in community-dwelling older adults with mild-to-moderate dementia due to AD.Methods:This study was a secondary analysis of the Effects of Aerobic Exercise for Treating Alzheimer’s Disease(FIT-AD)trial data.Aerobic fitness was measured by the shuttle walk test(SWT),the 6-min walk test(6MWT),and the maximal oxygen consumption(VO2max)test,and cognition by the AD Assessment Scale-Cognition(ADAS-Cog).Inter-individual differences were calculated as the differences in the standard deviation of 6-month change(SDR)in the SWT,6MWT,VO2max,and ADAS-Cog between the intervention and control groups.Results:Seventy-eight participants were included in this study(77.4±6.3 years old,mean±SD;15.7±2.8 years of education;41%were female).VO2max was available for 26 participants(77.7±7.1 years old;14.8±2.6 years of education;35%were female).The SDR was 37.0,121.1,1.7,and 2.3 for SWT,6MWT,VO2max,and ADAS-Cog,respectively.Conclusion:There are true inter-individual differences in aerobic fitness and cognitive responses to aerobic exercise in older adults with mild-tomoderate dementia due to AD.These inter-individual differences likely underline the inconsistent cognitive benefits in human studies.     

Sex equity in French newspaper photographs: A content analysis of 2012 Olympic Games by L'Equipe

Abstract

The aim of this article was to examine sex equity in the photographic coverage of the London 2012 Olympic Games by a French sports daily newspaper. A sample of 1073 photographs was collected and analysed. A content analysis was carried out focusing on the number of photographs, the space they cover, their location and position, the type and colour of shot and the sport they depict. A significant under-representation of female athletes’ photographs was found. However, contrary to most of previous research in this field, the other quantitative and qualitative variables do not show any differences. Furthermore, a significant positive correlation between the number of photographs for each sport and the number of French medals was found (for women, for men and for the whole sample), suggesting that the photographic coverage of this event is mainly based on the success of French athletes independently of their sex.     

A systematic review of siblings and physical activity experiences

Siblings are important developmental agents, yet understanding of their influence in physical activity settings is limited. Prior to developing sibling-focused research questions, a comprehensive summary of the diverse literature regarding siblings in the physical domain is needed. A systematic review of siblings in physical activity contexts was conducted to gauge current knowledge on this topic and provide a guide for future empirical endeavors. A comprehensive literature search of CINAHL, The Cochrane Library, PsychINFO, PubMed, SPORTDiscus, and Web of Science yielded 68 studies spanning 46 years (1970–2016). The results showed siblings to be actively and passively associated with physical activity levels and to be sources of both positive and negative experiences in sport. The sex composition of sibling dyads appears to moderate outcomes. Overall, the findings provide an outline of sibling-based subject areas, identify topics needing further attention, and showcase methods with potential to advance the study of sibling relationships in the physical domain.     

Exercise and inflammation in coronary artery disease: A systematic review and meta-analysis of randomised trials

ABSTRACT

Current evidence suggests that chronic inflammation contributes to the development of coronary artery disease (CAD). Interestingly, exercise may constitute a method of reducing inflammation in this patient population. As such, this systematic review and meta-analysis examined the evidence generated by randomised studies that investigated the effect of exercise on inflammatory biomarkers in CAD. Literature was sought from various sources. Outcomes were pooled in a random-effects model to calculate standardised mean differences (SMD) with 95% confidence intervals (CI). Twenty-five studies were reviewed; post-intervention C-reactive protein (SMD: ?0.55 (95% CI: ?0.93, ?0.16), P = 0.005), fibrinogen (SMD: ?0.52 (95% CI: ?0.74, ?0.29, P = <0.00001)), and von Willebrand factor (SMD: ?1.57 (95% CI: ?2.23, ?0.92), P = <0.00001) values were significantly lower in exercise groups compared to controls. In addition, qualitative analyses identified evidence that supports a beneficial effect of exercise on these acute-phase reactants. However, the impact of exercise on anti–inflammatory cytokines, adhesion molecules, and chemokines is equivocal, which may be attributed to a paucity of research. Nevertheless, the findings of this review suggest that exercise induces an anti–inflammatory effect in CAD patients. Although, the quality of evidence needs to be improved by further randomised studies with high methodological qualities and large sample sizes.     

A comparison of lactate indices during ramp exercise using modelling techniques and conventional methods

Abstract

The aim of this study was to compare the lactate indices provided by single- and double-breakpoint models with lactate thresholds obtained with conventional methods. Arterial samples for the determination of lactate concentrations were drawn from eight participants at rest and every minute during a ramp test (15 W · min^?1) on a cycle ergometer. Lactate thresholds were determined from a blood lactate concentration equal to 4 mM (LT₄), from an increase of 1 mM above the resting level (Δ1 mM), and from indirect methods using ventilatory parameters. Other indices were computed from the modelling of the lactate curve using an exponential function (LSI), a polynomial function (Dmax), a semi-log model (SLog), a parabola plus delay model (Mod P), and a two-breakpoint model (Mod M). Mod P and Mod M showed poor agreement with the other methods. LT₄, Dmax, LSI, and respiratory exchange ratio equal to 1 were correlated with each other (0.81 ≤ R ≤ 0.92) and their mean differences ranged from 2.8 to 15 W, with limits of agreement within the range ± 24.6 to ± 42.4 W. These results question the interest in breakpoints models to detect lactate thresholds, knowing that LT₄, LSI, Dmax, and respiratory exchange ratio equal to 1 provide indices that occur at similar power outputs.     

Metabolic response to 6-week aerobic exercise training and dieting in previously sedentary overweight and obese pre-menopausal women: A randomized trial

BackgroundThe aim of this study was to compare 6 weeks short-term moderate intensity aerobic exercise and dieting on serum metabolomics and cardio-metabolic risk factors in pre-menopausal women.MethodsNinety previously inactive overweight and obese (BMI 25–35 kg/m²) women (age 41.5 ± 7.6 years) were randomized to either a 6-week Nordic walking exercise program (EX, n = 45) or dietary counseling group (DI, n = 45). Body composition, serum glucose, insulin and lipids were measured. Serum low-molecular-weight metabolites and lipid constituents were analyzed by nuclear magnetic resonance spectroscopy. Measurements were done at baseline and 7 days after the last training session.ResultsSix weeks aerobic exercise program yielded reductions in serum free fatty acids (−34.7%, 95% confidence interval (CI), −50 to −18, p < 0.001), glucose (−9.6%, 95%CI, −15 to −4, p < 0.001) and homeostasis model assessment of insulin resistance (HOMA-IR) (−28.7%, 95%CI, −48 to −10, p = 0.005) without changes in body weight or fat mass. Diet counseling resulted in loss of body weight (1.5%, 95%CI, −2.3 to −0.7, p = 0.001) but no changes in free fatty acids, fasting glucose, or HOMA-IR were found.ConclusionOur results indicate that small weight loss does not produce measurable health benefits, whereas short-term regular aerobic exercise can improve glucose and lipid metabolism even in the absence of weight loss in previously sedentary overweight and obese women.     

Tai Ji Quan as antihypertensive lifestyle therapy: A systematic review and meta-analysis

BackgroundProfessional health organizations are not currently recommending Tai Ji Quan alongside aerobic exercise to treat hypertension. We aimed to examine the efficacy of Tai Ji Quan as antihypertensive lifestyle therapy.MethodsTai Ji Quan interventions published in English and Chinese were included when they involved healthy adults, reported pre- and post-intervention blood pressure (BP), and had a non-exercise/non-diet control group. We systematically searched 11 electronic databases for studies published through July 31, 2018, yielding 31 qualifying controlled trials. We (1) evaluated the risk of bias and methodological study quality, (2) performed meta-regression analyses following random-effects assumptions, and (3) generated additive models representing the largest possible clinically relevant BP reductions.ResultsParticipants (n = 3223) were middle-aged (56.6 ± 15.1 years of age, mean ± SD) adults with prehypertension (systolic BP (SBP) = 136.9 ± 15.2 mmHg, diastolic BP (DBP) = 83.4 ± 8.7 mmHg). Tai Ji Quan was practiced 4.0 ± 1.4 sessions/week for 54.0 ± 10.6 min/session for 22.3 ± 20.2 weeks. Overall, Tai Ji Quan elicited significant reductions in SBP (–11.3 mmHg, 95%CI: –14.6 to –8.0; d₊ = –0.75) and DBP (–4.8 mmHg, 95%CI: –6.4 to –3.1; d₊ = –0.53) vs. control (p < 0.001). Controlling for publication bias among samples with hypertension, Tai Ji Quan trials published in English elicited SBP reductions of 10.4 mmHg and DBP reductions of 4.0 mmHg, which was half the magnitude of trials published in Chinese (SBP reductions of 18.6 mmHg and DBP reductions of 8.8 mmHg).ConclusionOur results indicate that Tai Ji Quan is a viable antihypertensive lifestyle therapy that produces clinically meaningful BP reductions (i.e., 10.4 mmHg and 4.0 mmHg of SBP and DBP reductions, respectively) among individuals with hypertension. Such magnitude of BP reductions can lower the incidence of cardiovascular disease by up to 40%.     

Effects of weightlifting exercise,traditional resistance and plyometric training on countermovement jump performance: a meta-analysis

Jump performance is considered an important factor in many sports. Thus, strategies such as weightlifting (WL) exercises, traditional resistance training (TRT) and plyometric training (PT) are effective at improving jump performance. However, it is not entirely clear which of these strategies can enable greater improvements on jump height. Thus, the purpose of the meta-analysis was to compare the improvements on countermovement jump (CMJ) performance between training methods which focus on WL exercises, TRT, and PT. Seven studies were included, of which one study performed both comparison. Therefore, four studies comparing WL exercises vs. TRT (total n = 78) and four studies comparing WL exercises vs. PT (total n = 76). The results showed greater improvements on CMJ performance for WL exercises compared to TRT (ES_diff: 0.72 ± 0.23; _95%CI: 0.26, 1.19; P = 0.002; Δ % = 7.5 and 2.1, respectively). The comparison between WL exercises vs. PT revealed no significant difference between protocols (ES_diff: 0.15 ± 0.23; _95%CI: ?0.30, 0.60; P = 0.518; Δ % = 8.8 and 8.1, respectively). In conclusion, WL exercises are superior to promote positive changes on CMJ performance compared to TRT; however, WL exercises and PT are equally effective at improving CMJ performance.     

Oxygen uptake during mini trampoline exercise in normal-weight,endurance-trained adults and in overweight-obese,inactive adults: A proof-of-concept study

Objectives: To examine cardiorespiratory exertion during mini trampoline exercises of different intensities in both endurance-trained athletes and overweight-obese adults. Methods: Physically healthy participants (Group A: normal-weight, endurance-trained athletes; Group B: inactive, overweight-obese adults) participated in two measurement appointments and three training sessions in between appointments, in which participants familiarized themselves with the use of the mini trampoline and the execution of the exercises. The primary outcome was the ?O_2peak for each of the six mini trampoline exercises relative to the ?O_2peak as established during an all-out exercise test on a bike ergometer during the first measurement appointment. Secondary outcomes were average ?O₂ as well as maximum and average heart rate. Results: The six mini trampoline exercises generated ?O_2peak values between 42% and 81% in the endurance-trained athletes and between 58% and 87% in the overweight-obese participants, both in relation to the bike ergometer ?O_2peak. Average ?O₂ values ranged from 35% to 69% (endurance-trained athletes) and from 48% to 71% (overweight-obese participants), depending on exercise. Average heart rate likewise lay in a range that can be categorized as moderate-to-vigorous aerobic exercise for both groups. A moderate-to-strong correlation (0.658 to 0.875, depending on exercise) between bike ergometer ?O_2peak and mini trampoline ?O_2peak was found for all six exercises. Conclusions: Mini trampoline exercise has the potential to produce training intensities that concur with established exercise guidelines. The exercise intensity is self-adjusting and allows for an effective and safe workout for different users with a wide range of fitness levels.     

Attitudes and exercise adherence: Test of the Theories of Reasoned Action and Planned Behaviour

Three studies of exercise adherence and attitudes are reported that tested the Theory of Reasoned Action and the Theory of Planned Behaviour. In a prospective study of adherence to a private fitness club, structural equation modelling path analysis showed that attitudinal and social normative components of the Theory of Reasoned Action accounted for 13.1% of the variance in adherence 4 months later, although only social norm significantly predicted intention. In a second study, the Theory of Planned Behaviour was used to predict both physical activity and sedentary behaviour. Path analyses showed that attitude and perceived control, but not social norm, predicted total physical activity. Physical activity was predicted from intentions and control over sedentary behaviour. Finally, an intervention study with previously sedentary adults showed that intentions to be active measured at the start and end of a 10-week intervention were associated with the planned behaviour variables. A multivariate analysis of variance revealed no significant multivariate effects for time on the planned behaviour variables measured before and after intervention. Qualitative data provided evidence that participants had a positive experience on the intervention programme and supported the role of social normative factors in the adherence process.     

The effects of short versus long inter-set rest intervals in resistance training on measures of muscle hypertrophy: A systematic review

Although the effects of short versus long inter-set rest intervals in resistance training on measures of muscle hypertrophy have been investigated in several studies, the findings are equivocal and the practical implications remain unclear. In an attempt to provide clarity on the topic, we performed a systematic literature search of PubMed/MEDLINE, Scopus, Web of Science, Cochrane Library, and Physiotherapy Evidence Database (PEDro) electronic databases. Six studies were found to have met the inclusion criteria: (a) an experimental trial published in an English-language peer-reviewed journal; (b) the study compared the use of short (≤60?s) to long (>60?s) inter-set rest intervals in a traditional dynamic resistance exercise using both concentric and eccentric muscle actions, with the only difference in resistance training among groups being the inter-set rest interval duration; (c) at least one method of measuring changes in muscle mass was used in the study; (d) the study lasted for a minimum of four weeks, employed a training frequency of ≥2 resistance training days per week, and (e) used human participants without known chronic disease or injury. Current evidence indicates that both short and long inter-set rest intervals may be useful when training for achieving gains in muscle hypertrophy. Novel findings involving trained participants using measures sensitive to detect changes in muscle hypertrophy suggest a possible advantage for the use of long rest intervals to elicit hypertrophic effects. However, due to the paucity of studies with similar designs, further research is needed to provide a clear differentiation between these two approaches.     

Comparing the effects of low and high load resistance exercise to failure on adaptive responses to resistance exercise in young women

The aim of this study was to compare the effect of 6 weeks of resistance training to volitional failure at low (30% 1 repetition maximum (RM)) or high (80%1RM) loads on gains in muscle size and strength in young women. Thirteen women (age: 29.7 ± 4.7years; height 166.7 ± 6.4cm; weight 64.2 ± 12.2kg) completed 2 training sessions per week for 6 weeks and muscle strength (1RM), muscle thickness (ultrasound) were measured before and after training. Training comprised 1 set to volitional failure of unilateral leg extensions and bicep curls with each limb randomly assigned to train at either 80% 1RM or 30% 1RM. Increases in muscle thickness [arms: 6.81 ± 3.15% (30% 1RM), 5.90 ± 3.13% (80% 1RM) and legs: 9.37 ± 5.61% (30% 1RM), 9.13 ± 7.9% (80% 1RM)] and strength [arms: 15.4 ± 12.2% (30% 1RM), 18.26 ± 12.2% (80% 1RM) and legs: 25.30 ± 18.4 (30% 1RM), 27.20 ± 14.5 (80% 1RM)] were not different between loads. When resistance exercise is performed to volitional failure gains in muscle size and strength are independent of load in young women.     

Effect of body composition on redox homeostasis at rest and in response to exercise: The case of underfat women

Underfat individuals have been neglected as a malnourished population in terms of redox homeostasis. The aim of the present study was to evaluate the effect of body composition on redox homeostasis at rest and in response to exercise. Underfat, lean and overfat women, classified according to their BMI and body fat percentage, participated in the study and were subjected to an acute session of eccentric exercise. With regard to muscle function and damage, a significant group × time interaction was found for range of motion (P < .01), isometric peak torque at 90° (P < .01), delayed onset muscle soreness (P < .01) and creatine kinase (P < .05), with the lean group generally exhibiting faster recovery compared to the underfat and overfat groups. With regard to redox homeostasis, a significant group × time interaction was found for F₂-isoprostanes, protein carbonyls and glutathione (P < .01 for all biomarkers), with the underfat and overfat groups exhibiting increased resting oxidative stress levels and lower exercise-induced reactive species production . In conclusively, our data underline the importance of normal body composition for redox homeostasis, since underfat and overfat women demonstrate a similar pattern of redox disturbances both at rest and in response to exercise.