Optimizing generalized motor program and parameter learning

Two experiments examined generalized motor program (GMP) and parameter learning. Experiment 1 examined the effects of bandwidth knowledge of results (KR) about relative timing in constant and variable practice. The purpose was to determine if movement stability created by the bandwidth manipulation is associated with increased GMP learning and if bandwidth KR interacts with constant and variable practice. Participants were asked to depress four keys sequentially, using the same relative timing structure. Constant practice had one absolute timing requirement, whereas variable practice had three different absolute timing requirements. The results indicated that GMP learning was enhanced by constant practice (independent of the bandwidth KR condition) and by bandwidth KR, when variable practice was used. The findings suggest practice conditions (bandwidth KR, constant practice) that increase movement stability during practice enhance GMP learning. Parameter learning (during transfer), however, was enhanced by variable practice. Experiment 2 attempted to determine how constant and variable practice conditions could be combined to enhance both GMP and parameter learning. The results indicated that developing a stable GMP early in practice--by providing learners with constant practice early in practice--and refining parameter learning later in practice--by providing them with variable practice late in practice--were effective for both GMP and parameter learning. This suggests a hierarchy in the development of programmed actions with a stable GMP being a requisite for developing an effective and stable parameter rule.     

The effect of self-regulated and experimenter-imposed practice schedules on motor learning for tasks of varying difficulty

Research suggests that allowing individuals to control their own practice schedule has a positive effect on motor learning. In this experiment we examined the effect of task difficulty and self-regulated practice strategies on motor learning. The task was to move a mouse-operated cursor through pattern arrays that differed in two levels of difficulty. Participants learned either four easy or hard patterns after assignment to one of four groups that ordered practice in blocked, random, self-regulated, and yoked-to-self-regulated schedules. Although self-regulation provided no special benefit in acquisition, these groups showed the most improved performance in retention, irrespective of task difficulty. Although individual switch strategies for members of the self-regulated groups were quite variable, the impact of self-regulation on motor learning remained similar. These findings add to the growing body of literature suggesting that self-regulated practice is an important variable for motor learning.     

Self-control of task difficulty during training enhances motor learning of a complex coincidence-anticipation task

The aim of the present work was to analyze the influence of self-controlled task difficulty on motor learning. Participants had to intercept three targets falling at different velocities by displacing a stylus above a digitizer Task difficulty corresponded to racquet width. Half the participants (self-control condition) could choose the racquet width at the beginning of each trial. Each was paired with a participant from the yoked group. The self-control condition resulted in better performances and accuracy during immediate and delayed retention tests. These results confirm the advantage of a self-control condition on motor learning. They are discussed with reference to the challenge point hypothesis (Guadagnoli & Lee, 2004).     

Carbohydrate mouth rinse does not affect performance during a 60-min running race in women

This study examined the effect of carbohydrate mouth rinsing on endurance running performance in women. Fifteen female recreational endurance runners, who used no oral contraceptives, ran two races of 1-h duration on an indoor track (216-m length) at 18:00 h after an 8-h fast with a 7-days interval between races, corresponding to the 3^rd-10th day of each premenopausal runner’s menstrual cycle, or any day for the postmenopausal runners. In a double-blind random order, participants rinsed their mouth with 25 ml of either a 6.4% carbohydrate (RCHO) or a placebo solution (RP). No fluid was ingested during exercise. Serum 17β-Εstradiol (P = 0.59) and Progesterone (P = 0.35) did not differ between treatments. There was no difference in 1-hour running performance (RCHO: 10,621.88 ± 205.98 m vs. RP: 10,454.00 ± 206.64 m; t = 1.784, P = 0.096). Furthermore, the mean percentage effect (±99%CI) of RCHO relative to RP, 1.67% (?1.1% to 4.4%), and Cohen’s effect size (d = 0.21) support a trivial outcome of RCHO for total distance covered. In conclusion, carbohydrate mouth rinsing did not improve 60-min track running performance in female recreational runners competing in a low ovarian hormone condition, after an 8-h fast and when no fluid was ingested during exercise.     

Caffeine supplementation does not affect match activities and fatigue resistance during match play in young football players

Abstract

The study examined the effect of caffeine supplementation on match activities and development of fatigue during a football match. In a randomised, double-blind cross-over design, two experimental football games separated by 7 days were organised between the junior teams of two professional football clubs (17.6 ± 1.1 years (±s), 71.7 ± 6.9 kg, 13.9% ± 5.0% body fat). The players ingested either a capsule of 6 mg · kg^?1 b.w. caffeine or placebo (dextrose) 65 min prior to the matches. Match activities were assessed using the ZXY match analysis system, and a Yo-Yo intermittent recovery test–level 2 (Yo-Yo IR2) was conducted immediately post-game. Heart rate was monitored throughout the game, and blood samples were obtained at baseline, half-time and after the game. There were no differences between caffeine and placebo regarding total distance covered (10,062 ± 916 vs 9854 ± 901 m), high-intensity running (557 ± 178 vs 642 ± 240 m), sprinting distance (109 ± 58 vs 112 ± 69 m) or acceleration counts (123 ± 31 vs 126 ± 24). In both trials, players displayed lower (P < 0.05) values in total distance and acceleration counts in the last 15 min compared to all other 15-min periods of the matches. Post-game Yo-Yo IR2 performance was not different between game trials (caffeine: 829 ± 322 m; placebo 819 ± 289 m). In conclusion, oral caffeine administration does not appear to have an ergogenic effect in young football players during match play.     

False-performance feedback does not affect punching forces and pacing of elite boxers

Prior research indicates that providing participants with positive augmented feedback tends to enhance motor learning and performance, whereas the opposite occurs with negative feedback. However, the majority of studies were conducted with untrained participants performing unfamiliar motor tasks and so it remains unclear if elite athletes completing familiar tasks respond in a similar fashion. Thus, this study investigated the effects of three different versions of false-performance feedback on punching force (N), pacing (force over time) and ratings of perceived exertion (RPE) in 15 elite amateur male boxers. Athletes completed a simulated boxing bout consisting of three rounds with 84 maximal effort punches delivered to a punching integrator on four separate days. Day one was a familiarisation session in which no feedback was provided. In the following three days athletes randomly received false-positive, false-negative and false-neutral feedback on their punching performance between each round. No statistical or meaningful differences were observed in punching forces, pacing or RPE between conditions (P > 0.05; ≤ 2%). These null results could stem from the elite status of the athletes involved, the focus on performance rather than learning, or they may indicate that false feedback has a less potent effect on performance than previously thought.     

运动技能学习困难小学生体质和心理健康的量化研究

采用测量法、问卷调查法、数理统计法,对武汉市3所小学95名(男生65人,女生30人)运动技能学习困难学生的体质和心理健康进行了研究,旨在了解这一特殊群体的体质健康和心理健康水平,以便更好地促进其全面健康地发展。     

运动技能学的迁移研究与练习法的分类

借鉴国外运动技能学有关迁移的研究结果对我国相对落后的练习法研究具有迫切意义.练习法分类的重要性以及我国当前练习法分类体系所存在的问题,要求我们重新审视练习法分类体系.以运动技能学习的迁移规律作为分类标准,可对练习法进行理想的分类.     

Enhancing motor learning through dyad practice: contributions of observation and dialogue

It has been shown that practice in dyads, as compared to individual practice, can enhance motor learning and increase the efficiency of practice (as two participants can be trained at the same time; Shea, Wulf, & Whitacre, 1999). The dyad practice protocol used by Shea et al. included both observation and dialogue between partners. Thus, it was not clear whether the learning benefits of dyad practice were due to observation, dialogue, or both. The present study examined the individual and interactive effects of observation and dialogue. The task used was speed cup stacking. Participants practiced under one of four conditions: observation/dialogue, observation/no dialogue, no observation/dialogue, and no observation/no dialogue. The two conditions that included observational practice were more effective (i.e., produced faster movement times) than the two conditions without it, both during practice and on a retention test performed under individual performance conditions. This suggests that the learning advantages of dyad practice are primarily due to the opportunity to observe another learner.     

Decreasing the proportion of self-control trials during the acquisition period does not compromise the learning advantages in a self-controlled context

The present experiment examined the learning effects of participants self-controlling their receipt of knowledge of results (KR) on all or half of their acquisition trials (50%). For participants who were provided 50% self-control, the first half of their acquisition period consisted of receiving KR on all trials, or according to a faded-KR schedule. Participants practiced a sequential timing task. The results showed that independent of practice condition, participants who self-controlled their KR during the acquisition period demonstrated superior performance compared to the respective yoked conditions in the retention and transfer portion of the experiment. These results extend previous research by suggesting that decreasing the proportion of self-control trials does not compromise learning in a self-controlled context.     

Distribution of practice and metacognition in learning and long-term retention of a discrete motor task

This study examined judgments of learning and the long-term retention of a discrete motor task (golf putting) as a function of practice distribution. The results indicated that participants in the distributed practice group performed more proficiently than those in the massed practice group during both acquisition and retention phases. No significant differences in retention performance were found as a function of three retention intervals (1, 7, and 28 days). Echoing actual acquisition scores, participants in the distributed practice group predicted more proficient retention performance than did those in the massed practice group. Although all participants predicted more proficient performance than was actually achieved, the difference between predicted and actual performance failed to reach significance.     

Musculoskeletal stiffness during hopping and running does not change following downhill backwards walking

Eccentric contractions that provide spring energy can also cause muscle damage. The aim of this study was to explore leg and vertical stiffness following muscle damage induced by an eccentric exercise protocol. Twenty active males completed 60 minutes of backward-walking on a treadmill at 0.67 m/s and a gradient of ? 8.5° to induce muscle damage. Tests were performed immediately before; immediately post; and 24, 48, and 168 hours post eccentric exercise. Tests included running at 3.35 m/s and hopping at 2.2 Hz using single- and double-legged actions. Leg and vertical stiffness were measured from kinetic and kinematic data, and electromyography (EMG) of five muscles of the preferred limb were recorded during hopping. Increases in pain scores (over 37%) occurred post-exercise and 24 and 48 hours later (p < 0.001). A 7% decrease in maximal voluntary contraction occurred immediately post-exercise (p = 0.019). Changes in knee kinematics during single-legged hopping were observed 168 hours post (p < 0.05). No significant changes were observed in EMG, creatine kinase activity, leg, or vertical stiffness. Results indicate that knee mechanics may be altered to maintain consistent levels of leg and vertical stiffness when eccentric exercise-induced muscle damage is present in the lower legs.     

How does mental fatigue affect soccer performance during small-sided games? A cognitive,tactical and physical approach

ABSTRACT

Objectives

We examine how mental fatigue (MF) influences peripheral perception, tactical behaviour, and physical performance of soccer players during a standardized small-sided game.