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  • Author: Robert J. Smith x
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Daniel S. Kirschenbaum and Robert J. Smith

In this study, experimenters (pseudo-coaches) provided feedback that varied in valence, sequence, and amount to 50 male college students. A laboratory analogue paradigm was used that included a basketball-like underhand free throw task in which subjects first were instructed on proper technique and then took 10 baseline shots (trials) followed by 2 blocks of 20 trials each. Subjects were randomly assigned. Some interacted with a pseudo-coach who made no comments during the two experimental trial blocks (control), while others received feedback (6-8 comments per trial block) that was response-specific, emotionally oriented, and provided in one of four sequences: positive-positive, negative-negative, positive-negative, or negative-positive. Based on prior research on coach behavior and social psychological studies of interpersonal behavior, we hypothesized that both of the continuous feedback groups would show performance decrements and associated reactions to the coach and the task. These predictions were supported regarding performance and, to some extent, regarding a measure of sustained self-observation. Discussion includes interpretation of the nominally superior performance of the control group, the nonsignificant results on the subjective evaluation measures, and implications of these findings in view of external validity criteria and prior analyses in the emerging behavioral technology of coaching.

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Gareth J. Smith, Edward C. Rhodes and Robert H. Langill

The purpose of this study was to determine if pre-exercise glucose ingestion would improve distance swimming performance. Additionally, pre-exercise glucose was provided at 2 different feeding intervals to investigate the affects of the timing of administration. Ten male triathletes (X¯±SD: age, 29.5 ± 5.0 years; V̇O2peak, 48.8 ± 3.2 ml · kg’1 · min’) swam 4000 m on 3 occasions following the consumption of either a 10% glucose solution 5 min prior to exercise (G5), a 10% glucose solution 35 min prior to exercise (G35), or a similar volume of placebo (PL). Despite a significant difference (p < ,01) in blood glucose concentration prior to exercise (X¯±SD in mmol · L ’: G" 8.4 ± 1.1 vs. G5 5.2 ± 0.5 or PL 5.3 ± 0.4), no significant differences were observed in total time (X¯±SD in minutes: G* 70.7 ± 7.6, Gs 70.1 ± 7.6. PL 71.9 ± 8.4). post-exercise blood glucose (X¯±SD inmmol · L−1: G35 5.1 ± 1.1, G5 5.1 ± 0.9, PL 5.3 ± 0.4), and average heart rate (X¯±SD in bpnv.G" 155.8±10.8, G5 153.6±12.6. PL 152.0± 12.5; p > .05). While not reaching statistical significance, glucose feedings did result in improved individual performance times, ranging from 24 s to 5 min in 8 of the 10 subjects compared to the placebo. These results were found despite significant differences in blood glucose between trials immediately prior to exercise.

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Robert J. Gregor, Judith L. Smith, Dagan W. Smith, Alanna Oliver and Boris I. Prilutsky

Different forms of locomotion have been studied in the cat in an effort to understand the neural mechanisms involved in movement control. Recent studies have focused on the roles of one- and two-joint muscles, the integration of central commands with sensory input, and the notion that the control system may be organized around the mechanical actions of muscles and the number of joints they span. To investigate the load-sharing between the two-joint medial gastrocnemius and one-joint soleus muscles, a single cat was trained to walk in an instrumented Plexiglas enclosed walkway at slopes ranging ±75%. Surgically implanted tendon force transducers monitored force output from each muscle. Equations in Newtonian mechanics were used to calculate joint kinetics. Results suggest that as slope angle decreased, the one-joint soleus became the primary contributor to the plantar-flexor moment calculated during stance. Unexpectedly, as slope angle increased, force in the one-joint soleus decreased while force in the two-joint medial gastrocnemius increased in the presence of the increased plantar-flexor moment calculated during stance. One explanation is that activation and force in the two-joint medial gastrocnemius should increase in the presence of a knee flexor and plantar-flexor moment. This was the case during upslope walking, as two-joint muscles increase their activation when they act as an agonist at both joints they cross. Additionally, a force-dependent inhibition of the soleus by the medial gastrocnemius has been described as part of a neural control system organized around the mechanical actions of muscles and the number of joints they span. Hence, a decrease in one-joint soleus force might be expected under certain conditions in upslope walking.

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Daniel J. Daly, Laurie A. Malone, David J. Smith, Yves Vanlandewijck and Robert D. Steadward

A video race analysis was conducted at the Atlanta Paralympic Games swimming competition. The purpose was to describe the contribution of clean swimming speed, as well as start, turn, and finish speed, to the total race performance in the four strokes for the men’s 100 m events. Start, turn, and finish times, as well as clean swimming speed during four race sections, were measured on videotapes during the preliminary heats (329 swims). Information on 1996 Olympic Games finalists (N = 16) was also available. In Paralympic swimmers, next to clean swimming speed, both turning and finishing were highly correlated with the end race result. Paralympic swimmers do start, turn, and finish slower than Olympic swimmers but in direct relation to their slower clean swimming speed. The race pattern of these components is not different between Paralympic and Olympic swimmers.

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Daniel S. Kirschenbaum, David A. Wittrock, Robert J. Smith and William Monson

We propose that training athletes to use certain cognitive-behavioral procedures, “criticism inoculation training” (CIT), could enable them to circumvent the adverse effects of excessively negativistic coaching. This experiment evaluated the efficacy of one potential CIT strategy, positive self-monitoring (systematically observing and recording instances of success). A laboratory paradigm was used in which 60 male college students attempted to learn the underhand free throw basketball technique from one of four undergraduate pseudocoaches. Subjects were randomly assigned to four groups determined by a 2 (negative vs. no feedback) × 2 (positive vs. no self-monitoring) factorial design. Negative feedback was expected to debilitate, while positive self-monitoring was expected to facilitate performance, sustained self-observation of videotapes of performance, and subjective evaluations of the “coach” and the technique. Negative feedback clearly produced extensive adverse effects, but surprisingly, positive self-monitoring also decreased performance. Theories of skilled motor behavior (MacKay, 1982) and self-regulation (Carver, 1979) helped explain why positive self-monitoring failed as a CIT procedure. This interpretation which focuses on the novelty of the task and the development of negative expectancies also led to suggestions of strategies that could more effectively fulfill the promise of the CIT concept.

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Ronald E. Smith, Robert W. Schutz, Frank L. Smoll and J.T. Ptacek

Confirmatory factor analysis was used as the basis for a new form of the Athletic Coping Skills Inventory (ACSI). The ACSI-28 contains seven sport-specific subscales: Coping With Adversity, Peaking Under Pressure, Goal Setting/Mental Preparation, Concentration, Freedom From Worry, Confidence and Achievement Motivation, and Coachability. The scales can be summed to yield a Personal Coping Resources score, which is assumed to reflect a multifaceted psychological skills construct. Confirmatory factor analyses demonstrated the factorial validity of the ACSI-28, as the seven subscales conform well to the underlying factor structure for both male and female athletes. Psychometric characteristics are described, and preliminary evidence for construct and predictive validity is presented.

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Noreen D. Willows, Susan K. Grimston, Delia Roberts, David J. Smith and David A. Hanley

This study assessed serum ferritin, hemoglobin, and hematocrit among 107 physically active young people 9 to 18 years of age. Tanner stage (TS) of puberty was assessed and subjects were categorized as prepubertal (TS 1), midpubertal (TS 2, 3, and 4, excluding menarcheal females) and going through their rapid growth phase, or late pubertal (TS 5 and menarcheal females) and having completed their rapid growth phase. Midpubertal females had a lower hematocrit than late pubertal females, but there were no significant differences in serum ferritin or hemoglobin between pubertal groups. Late pubertal males had hemoglobin and hematocrit values that were higher than among prepubertal males, but serum ferritin did not differ. At late puberty the males had significantly higher serum ferritin, hemoglobin, and hematocrit compared with late pubertal females, and females in late puberty were more likely to have marginal iron stores compared with males at the same stage of pubertal development. Midpubertal and late pubertal females reported a diet low in absorbed iron, which could contribute to their poorer iron status.

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Andrea N. Lay, Chris J. Hass, D. Webb Smith and Robert J. Gregor

Sloped walking surfaces provide a unique environment for examining the bio-mechanics and neural control of locomotion. While sloped surfaces have been used in a variety of studies in recent years, the current literature provides little if any discussion of the integrity, i.e., validity, of the systems used to collect data. The goal of this study was to develop and characterize a testing system capable of evaluating the kinetics of human locomotion on sloped surfaces. A ramped walkway system with an embedded force plate was constructed and stabilized. Center of pressure and reaction force data from the force plate were evaluated at 6 ramp grades (0, 5, 15, 25, 35, and 39%). Ground reaction force data at 0% grade were effectively the same as data from the same force plate when mounted in the ground and were well within the range of intrasubject variability. Collectively, data from all tests demonstrate the fidelity of this ramp system and suggest it can be used to evaluate human locomotion over a range of slope intensities.