Understanding the Experiences of Heavy Smokers after Exercise

There is now strong evidence that exercise has an acute effect on the urge to smoke and the accompanying withdrawal symptoms. However, the perceptions by heavy smokers of exercise and its relationship to the urge to smoke have not been well documented. The aim of the present study is to understand the experiences of heavy smokers with regard to exercise and its effect on their urge to smoke. Five physically inactive, heavy smokers are asked to abstain from smoking the night before exercising on a cycle ergometer under two conditions (one at medium and one at vigorous intensity done a week apart). Semi-structured, in-depth interviews are conducted after the second exercise session. Thematic analysis reveals six themes describing the participants’ experience of exercise, urge to smoke, exercise preferences, exercise and smoking relationship, exercise as an aid to quit smoking, and the effects of the experimental procedure. Overall, the participants’ experiences support the existing literature, which has posited affective, biological, and cognitive mechanisms contributing to a delay in the urge to smoke after exercise. The main findings pertain to: (1) the “feel-good” effect after exercise as a relief from the “feel-bad” effect during exercise;(2) the decreased urge to smoke after exercise, stated by all participants regardless of reported positive and negative feelings;and (3) exercise as a “clearing the mind” mechanism rather than an attention-distracting mechanism.

The modulation of sirtuins and apoptotic proteins in rats after exhaustive exercise

A large body of evidence shows that a single bout of strenuous exercise induces oxidative stress in circu- lating human lymphocytes leading to lipid peroxide- tion, DNA damage, mitochondrial perturbations, and protein oxidation. In a training experiment, Wistar rats were divided into control group (CG) and exer- cise group (EG). After a running level exercise until exhaustion, we observed an increase in the mRNA content and protein expression of SIRT1 and SIRT7 in the EG compared to the CG. Moreover, such train- ing exercise did not change mRNA transcripts and protein expression of FOXO3A and GADD45. We also observed an increase of pro-apoptotic protein bax and a decrease of the anti-apoptotic protein bcl-2 in the EG. Accordingly, we observed a caspase-3 activation and poly (ADP-ribose) polymerase (PARP) cleavage only in EG rats. Statistical analysis of the data showed a significant correlation between SIRT1 and SIRT7 expression and apoptotic proteins such as bax, bcl-2 in both tissues. We conclude that, in both muscle, such exercise activates both a damaging apoptotic mecha- nism with bax increase and bcl-2 decrease and a counterbalancing protective mechanism with SIRT1 and SIRT7 increase.

An analysis of the size and direction of the association between mental toughness and Olympic distance personal best triathlon times

Background: Athletes, coaches, sport psychology practitioners, and researchers suggest that mental toughness represents an important construct that is associated with athletic performance. Unfortunately, the absence of real-world performance as a dependent variable has limited our ability to substantiate this claim. The concern of a lack of ecologically valid measures of sports performance might be addressed by examining the relationship between mental toughness and sports performance using a standardized measure of personal best(PB) triathlon time and a validated unidimensional measure of mental toughness.Methods: Three hundred and sixteen triathletes completed the 8-item mental toughness index(MTI), reported their age, and provided a PB Olympic distance triathlon time and the total number of triathlons they had completed to date. Given that males are typically quicker than females, a standardized time was calculated by dividing the PB by the current Olympic record for gender; we also hypothesized that more experienced triathletes would report quicker PB times because of greater frequency and duration of training. Once we had controlled for gender and experience,we predicted that mental toughness would be negatively associated with triathlon time and the size of the relationship would be of a moderate magnitude.Results: Results revealed small-to moderate-sized negative relationships between both completed number of triathlons and mental toughness with standardized PB time.Conclusion: The hierarchical regression analysis showed that mental toughness provided a unique contribution to the variability in standardized Olympic triathlon PB after controlling for the total number of triathlons completed.

Recreational team sports: The motivational medicine

Remember way back when?When we were kids?We played games like soccer,basketball,rugby,and volleyball because they were fun.If we stayed with it long enough(and became good enough)we might have played competitively,where the objective was to win.Herman Edwards,a former head coach in the National Football League(NFL)。

Evaluation of a concept-based physical education unit for energy balance education

Background:Physical education(PE)is a key channel that impacts children's decisions and behaviors for healthful living.This study evaluated the effects of a concept-based PE(CBPE)instructional unit,featured by energy balance(EB)education,on students'knowledge learning,situational interest,cognitive,and physical engagements as well as teachers'perceptions.Methods:Fourth and 5th grade students(n=468)in a mid-western state of the United States were recruited as the participants.Four elementary schools were randomized to the CBPE or control groups.Students'EB knowledge,situational interest,cognitive engagement,and physical engagement were measured by a knowledge test,the Situational Interest Scale—Elementary,written task sheets,and accelerometers,respectively,while teachers'perceptions of the CBPE unit were captured by individual interviews at the end of the experiment.Results:The CBPE group showed a significant increase in EB knowledge,while the control did not.Both groups showed a similar increasing trend for situational interest over time,although the statistical results favored the control group.For physical engagement,the CBPE group demonstrated a statistically different but substantively similar level of in-class physical activity compared to the control group.The CBPE group also showed a moderate level of cognitive engagement throughout the unit.The PE teachers reported overall positive perceptions about teaching the CBPE unit.Conclusion:These results support the utility of the CBPE unit in enhancing EB education along with facilitating positive student interest and engagement as well as positive teaching experiences.

Carbohydrate Supplementation during Exercise：Does It Help？How Much is Too Much？

KEY POINTS· Carbohydrate intake during exercise can delay the onset of fatigue and improve performance of prolonged exercise as well as exercise of shorter duration and greater intensity (e.g., continuous exercise lasting about 1h and intermittent high-intensity exercise), but the mechanisms by which performance is improved are different.

踏跳瞬间足后部骨骼的三维有限元分析

目的建立足部三维有限元模型,对足后部骨骼在踏跳中的应力分布进行分析。方法应用CT扫描和CAD/CAM软件处理,建立足后部骨骼三维模型。通过对背跃式跳高踏跳的足底压力测量和逆向肌肉力量计算,确定载荷约束条件,并进行有限元计算。结果获得了踏跳瞬间,跟骨、距骨、舟骨等易损伤部位的生物力学响应和应力分布,发现跟骨后距关节,距骨背面均为应力集中处。结论本研究建立的模型可用于足后部骨骼生物力学研究,为踏跳中的运动损伤力学机理提供数据。

Transition to forefoot strike reduces load rates more effectively than altered cadence

Background: Excessive vertical impacts at landing are associated with common running injuries. Two primary gait-retraining interventions aimed at reducing impact forces are transition to forefoot strike and increasing cadence. The objective of this study was to compare the shortand long-term effects of 2 gait-retraining interventions aimed at reducing landing impacts.Methods: A total of 39 healthy recreational runners using a rearfoot strike and a cadence of 170 steps/min were randomized into cadence(CAD) or forefoot strike(FFS) groups. All participants performed 4 weeks of strengthening followed by 8 sessions of gait-retraining using auditory feedback. Vertical average load rates(VALR) and vertical instantaneous load rates(VILR) were calculated from the vertical ground reaction force curve. Both cadence and foot strike angle were measured using 3D motion analysis and an instrumented treadmill at baseline and at 1 week,1 month, and 6 months post retraining.Results: ANOVA revealed that the FFS group had significant reductions in VALR(49.7%) and VILR(41.7%), and changes were maintained long term. Foot strike angle in the FFS group changed from 14.2° dorsiflexion at baseline to 3.4° plantarflexion, with changes maintained long term. The CAD group exhibited significant reduction only in VALR(16%) and only at 6 months. Both groups had significant and similar increases in cadence at all follow-ups(CAD, +7.2% to 173 steps/min;and FFS, +6.1% to 172 steps/min).Conclusion: Forefoot strike gait-retraining resulted in significantly greater reductions in VALR and similar increases in cadence compared to cadence gait-retraining in the short and long term. Cadence gait-retraining resulted in small reductions in VALR at only the 6-month follow-up.

为健康而运动：通过严肃娱乐促进全人发展？(英文)

1.Introduction After more than 50 years of research investigating physical activity and exercise there appears to be a clear consensus on the health benefits of this form of human behavior.Evidence from numerous studies examining exercise points to the physi-

Investigating the Modulatory Role of Chronological and Biological Age on Performance Predictors in Youth Swimmers

Purpose The aim of this study was to determine the modulatory roles of biological maturity and age on the predictors of performance in youth swimmers and their stability over a six-month training cycle.Methods In total,28 swimmers(10 pre-pubertal[6 boys],11.1±1.8 years;18 pubertal[8 boys],15.2±2.0 years old)and 26 untrained controls(15 pre-pubertal[10 boys],9.7±1.5 years;11 pubertal[6 boys],14.4±0.5 years old)were recruited.At baseline,3-and 6-months,participants completed an incremental ramp cycle test,isometric handgrip strength test and countermovement jumps,with speed assessed as a measure of performance in swimmers.Principle component analysis(PCA)identified factors that described youth swimmers’physical profile,with linear mixed models subsequently used to determine their interaction with age and maturity on performance.Results Aerobic fitness and upper body strength were significantly higher in the trained participants,irrespective of maturity status or time-point.Four key factors were identified through PCA(anthropometrics;strength;aerobic capacity;aerobic rate),accounting for 90%of the between parameter variance.Age exerted a widespread influence on swimming performance predic-tors,influencing all four factors,whilst maturity only influenced the aerobic factors.The key age of divergence was 13 years.Conclusion Overall,the present study found no evidence of a maturational threshold in the aerobic or strength-related response to training in youth.The influence of age on performance predictors suggests that utilising a single or select group of parameters to inform selection and/or talent identification throughout the dynamic processes of growth and maturation should be avoided.

Effects of Inspiratory Muscle Training on Heart Rate Variability in Children with Cystic Fibrosis:A Pilot Study

Purpose Cystic Fibrosis(CF)is a multisystem disease associated with symptoms such as dyspnoea,tachycardia and tachyp-nea that may be related to changes in autonomic function and sensitive to improvement following inspiratory muscle training(IMT).The aim of the present study was to investigate the effect of IMT on heart rate variability(HRV)and respiratory function in children.Methods Five CF and five matched controls(40%boys)performed a 4-weeks IMT programme,involving 30 breaths,twice a day.Weeks 1-2 of training were set at 40%of a participant's maximal strength index(S.Index),with week's 3-4 set at 50%.Participants wore an ActiHeart for three consecutive days at baseline and post-intervention and indices of HRV were derived.Standard measures of lung function were obtained along with health-related quality of life(HRQoL)using the CF-specific questionnaire(CFQ-R).Results IMT elicited clinically meaningful increases in respiratory muscle strength and respiratory symptom domain scores,but no improvements in respiratory volume,irrespective of group.Similarly,no significant improvements were found in HRQoL despite 62.5%of the population increased their HRQoL score.Post-intervention,CF participants showed a clinically meaningful decrease in the very low frequency(VLF)domain.Conclusion These results may indicate clinically meaningful changes in HRV and inspiratory muscle strength following a 4-week IMT intervention,although a more powerful study is required to draw further conclusions.Indeed,the trends for improved HRQoL support the need for such studies to ascertain the potential therapeutic role of IMT in those with CF.

Physical Characteristics Explain Ball-Carrying Capability in Sub-Elite Rugby Union Players

Purpose The aims of the present study were two-fold:(i)to investigate the relationship between physical characteristics and the game statistics associated with ball-carrying capability amongst sub-elite rugby union players,and(ii)to predict the level of change in these physical characteristics required to improve the associated game statistic via regression analysis.Methods Thirty-eight senior professional players(forwards,n=22;backs,n=16)were assessed for body mass(BM),back squat(BS)single-repetition maximum(1RM)normalised to BM(1RM/BM),10 m sprint velocity(S10),10 m sprint momentum(SM10),and the game statistics from 22 games within the 2019/20 RFU Championship season.The relationship between these measures and the predicted level of change in a physical measure required to improve the total number of the associated game statistic by one were assessed by Pearson’s correlation coefficient and simple regression analyses.Results In forwards,an~11.5%reduction in BM,an~11.8%improvement in BS 1RM/BM,or an~11.5%increase in S10 was required to improve the game statistics associated with ball-carrying capability.In backs,a~19.3%increase in BM or a~15.6%improvement in SM10 was required.Conclusions These findings demonstrate that improvements in lower-body relative strength,acceleration performance,and position-specific alterations in body mass are required to maximise the ball-carrying capability and therefore match outcome of sub-elite rugby union players.