Search results for "ta315"
showing 10 items of 465 documents
Implicit versus explicit attitude to doping: which better predicts athletes’ vigilance towards unintentional doping?
2018
Abstract Objectives This preliminary study examined whether implicit doping attitude, explicit doping attitude, or both, predicted athletes’ vigilance towards unintentional doping. Design A cross-sectional correlational design. Methods Australian athletes (N = 143; Mage = 18.13, SD = 4.63) completed measures of implicit doping attitude (brief single-category implicit association test), explicit doping attitude (Performance Enhancement Attitude Scale), avoidance of unintentional doping (Self-Reported Treatment Adherence Scale), and behavioural vigilance task of unintentional doping (reading the ingredients of an unfamiliar food product). Results Positive implicit doping attitude and explicit…
The Influence of University Students’ Stress Mindsets on Health and Performance Outcomes
2018
Background Emerging evidence indicates that holding particular stress mindsets has favorable implications for peoples’ health and performance under stress. Purpose The aim of the current study was to examine the processes by which implicit and explicit stress mindsets relate to health- and performance-related outcomes. Specifically, we propose a stress beliefs model in which somatic responses to stress and coping behaviors mediate the effect of stress mindsets on outcomes. Methods Undergraduate university students (N = 218, n = 144 females) aged 17– 25 years completed measures of stress mindset, physical and psychological wellbeing, perceived stress, perceived somatic responses to stress…
Effects of Sparring Load on Reaction Speed and Punch Force During the Precompetition and Competition Periods in Boxing.
2017
Seven, male, national-level boxers (age, 20.3 ± 2.7 years; height, 1.80 ± 0.06 m; mass, 73.8 ± 11.1 kg) participated in this study to investigate the effects of sparring on reaction time and punch force of straight punches measured during the precompetition and competition periods. Heart rate and blood lactate concentrations were also monitored. Sparring load was chosen in accordance with the current rules: 3 × 3-minute bouts with 1-minute break in between. Reaction time of rear straight lengthened (p < 0.01) during the sparring load of the precompetition period after the third round (to 390 milliseconds) in comparison to the competition period (to 310 milliseconds). Reaction time of lead s…
Age-specific neuromuscular interaction during elderly habitual running
2015
Aim It has been reported that advancing age causes tendons to become more compliant and fascicles length shorter. This could then lead to enhancement of movement efficiency provided that the elderly adults can activate their muscles in the same way as the younger adults (YOUNG) during dynamic movements. This study was designed to examine the age-specific behaviour of the medial gastrocnemius (MG) fascicles and tendinous tissues together with lower-leg muscle activities when the well-trained elderly runners ran on the treadmill at preferred speeds. Methods The well-trained 11 elderly subjects (ELD) who have running experiences and 11 YOUNG were recruited as subjects. While ELD were running o…
Heavy resistance exercise training and skeletal muscle androgen receptor expression in younger and older men
2010
Effects of heavy resistance exercise on serum testosterone and skeletal muscle androgen receptor (AR) concentrations were examined before and after a 21-week resistance training period. Seven healthy untrained young adult men (YT) and ten controls (YC) as well as ten older men (OT) and eight controls (OC) volunteered as subjects. Heavy resistance exercise bouts (5 × 10 RM leg presses) were performed before and after the training period. Muscle biopsies were obtained before and 1h and 48 h after the resistance exercise bouts from m.vastus lateralis (VL) to determine cross-sectional area of muscle fibers (fCSA) and AR mRNA expression and protein concentrations. No changes were observed in YC …
Age-related muscle activation profiles and joint stiffness regulation in repetitive hopping
2011
Abstract It is well documented that increasing effort during exercise is characterized by an increase in electromyographic activity of the relevant muscles. How aging influences this relationship is a matter of great interest. In the present study, nine young and 24 elderly subjects did repetitive hopping with maximal effort as well as with 50%, 65%, 75% and 90% intensities. During hopping joint kinematics were measured together with electromyographic activity (EMG) from the soleus, gastrocnemius medialis, gastrocnemius lateralis and tibialis anterior muscles. The results showed that agonist activation increased in both age groups with increasing intensity. The highest jumping efficiency (E…
Technical determinants of biathlon standing shooting performance before and after race simulation
2018
The aim of this study was to identify performance- determining factors in biathlon standing shooting in rest and after intense exercise. Eight Finnish national- and nine junior- team biathletes participated in the study. Participants fired 40 resting shots (REST) and 2 × 5 competition simulation shots (LOAD) after 5 minutes of roller skiing at 95% of peak heart rate. Hit percentage, aiming point trajectory and postural balance were measured from each shot. Cleanness of triggering (ATV, movement of the aiming point 0- 0.2 second before the shot) and vertical stability of hold (DevY) were the most important components affecting shooting performance both in REST (DevY, R = −0.61, P < .01; ATV,…
Differential contributions of ankle plantarflexors during submaximal isometric muscle action: A PET and EMG study
2014
Abstract The objective of this study was to investigate the relative contributions of superficial and deep ankle plantarflexors during repetitive submaximal isometric contractions using surface electromyography (SEMG) and positron emission tomography (PET). Myoelectric signals were obtained from twelve healthy volunteers (27.3±4.2yrs). A tracer ([ 18 F]-FDG) was injected during the exercise and PET scanning was done immediately afterwards. The examined muscles included soleus (Sol), medial gastrocnemius (MG), lateral gastrocnemius (LG), and flexor hallucis longus (FHL). It was found that isometric maximal voluntary contraction (MVC) force, muscle glucose uptake (GU) rate, and SEMG of variou…
Orderly display of limb lead ECGs raises Chinese intern’s diagnostic accuracy when determining frontal plane QRS axis
2019
Background: There is limited information on whether the orderly display of limb lead ECGs (electrocardiograms) can facilitate students to determine frontal plane QRS complex wave electrical axis. Objectives: The study investigated whether the orderly display of limb lead ECGs can raise Chinese undergraduate intern’s diagnostic accuracy when determining frontal plane axis. Design: A total of 147 fifth-year undergraduate interns aged between 21 and 25 years were randomly arranged into 2 groups: one group was given classically displayed ECGs of limb leads while the other group was given orderly displayed ECGs of limb leads. They were then taught to determine frontal plane axis with one of the …
Numerical relations and skill level constrain co-adaptive behaviors of agents in sports teams.
2014
Similar to other complex systems in nature (e.g., a hunting pack, flocks of birds), sports teams have been modeled as social neurobiological systems in which interpersonal coordination tendencies of agents underpin team swarming behaviors. Swarming is seen as the result of agent co-adaptation to ecological constraints of performance environments by collectively perceiving specific possibilities for action (affordances for self and shared affordances). A major principle of invasion team sports assumed to promote effective performance is to outnumber the opposition (creation of numerical overloads) during different performance phases (attack and defense) in spatial regions adjacent to the bal…