High School Swimmers Research Articles

Practicing research of the decision of estimated energy requirement in high school swimmers

Practicing research of the decision of estimated energy requirement in high school swimmers

Shoulder-Rotator Strength of High School Swimmers Over the Course of a Competitive Season

Context:Changes in strength over the course of a swim season could predispose the shoulder to strength imbalances and lead to injury.Objective:To examine isometric shoulder internal- (IR) and external-rotator (ER) strength in high school swimmers over a 12-week competitive season.Design:Three 3 × 2 × 2 ANOVAs with repeated measures were used to determine significant main effects for IR, ER, and IR:ER strength ratio.Participants:27 (14 female, 13 male) high school varsity swimmers.Main Outcome Measures:IR and ER strength during preseason, midseason, and postseason.Results:Significant increases in IR strength in both groups were revealed for all test sessions. ER strength significantly improved in both males and females from preseason to midseason and from preseason to postseason. IR:ER ratio revealed a significant increase from preseason to postseason.Conclusions:Increases in IR strength without equal gains in ER strength were revealed and could contribute to future shoulder pathologies in competitive swimmers

MUSCLE STRENGTH AND FLEXIBILITY IN YOUNG ELITE SWIMMERS

Research indicates that collegiate and Olympic swimmers display increased shoulder joint external rotation (ER) and decreased shoulder joint internal rotation (IR) ranges of motion (ROM). Swimmers show normal values for ER muscle strength but are proportionately overdeveloped regarding their IR muscle strength. These imbalances may predispose an athlete to shoulder injuries. Our goal was to determine if the physical characteristics of high school swimmers is consistent with the current body of knowledge regarding shoulder strength and ROM of elite level swimmers. Twenty-four subjects (age 14.5 ± 1.8) were recruited from a local swim club and reported to Blythedale Children's Hospital's Sports Medicine Center. Twenty-four subjects were evaluated for: body composition using bioelectrical impedance, shoulder IR and ER ROM using a hand-held goniometer, nd one-minute push-up repetition maximum (RM). Bilateral shoulder IR and ER torque (ft-lb) in the abducted position was assessed in eight subjects using an isokinetic dynamometer. Evaluations were made at speeds of 180 and 300 deg/sec. The results were as follows: percent body fat, 17.1 ± 5.6; push-up RM, 33.3 ± 12.1; IR ROM, 66.0 ± 13.3; ER ROM,89.6 ± 9.0; 180 deg/sec IR peak torque, 50.0 ± 19.2; 180 deg/sec ER peak torque, 21.2 ± 8.8; 300 deg/sec IR peak torque, 57.5 ± 27.2; 300 deg/sec ER peak torque, 31.9 ± 9.4; 180 deg/sec ER:IR peak torque ratio, 0.42:1; 300 deg/sec ER:IR peak torque ratio, 0.55:1. Normal ROM for IR is 70 and ER is 90. IR limitations may indicate a tight posterior capsule. A normal ER:IR torque ratio is 0.67. Abnormal ER:IR torque ratios indicate muscle strength imbalances. Our findings are consistent with the current literature and warrant investigation whether a strength and flexibility program can prevent these imbalances.

Alterations in scapular position with fatigue: a study in swimmers.

To use two commonly accepted measurement techniques to determine whether intense swimming exercise altered scapular position in male high school swimmers. Scapular position differences between dominant and nondominant shoulders were also investigated. A pilot study on 10 asymptomatic male volunteers established the reliability of the scapular position measurement techniques described by DiVeta and Kibler (intratester intraclass correlation coefficients 0.86-0.98). Scapular position was prospectively recorded before and after swimming practice just prior to tapering for championship competition. Twenty male high school swimmers from two local teams, ages 13 to 18 years. Subjects completed their usual 2-hour swimming practice at the peak of their training intensity. Change in scapular position preexercise versus postexercise. Scapular position did not change preexercise to postexercise for either the DiVeta (22.2 +/- 1.4 to 22.3 +/- 1.5 cm, p = 0.96) or Kibler (9.2 +/- 1.4 to 9.4 +/- 1.3 cm, p = 1.00) measures. Nondominant preexercise scapular position was generally more medial and moved laterally with exercise, becoming roughly equivalent to the dominant shoulder. The DiVeta and Kibler scapular position measurement techniques are acceptably reliable. However these techniques generally failed to demonstrate significant changes in scapular position after intense swimming exercise in the study population. Nondominant side scapulae typically moved laterally postexercise. These findings and implications are discussed.

標高1, 300mにおける水泳トレーニングが生理機能に及ぼす影響

To investigate effects of 1, 300 meters altitude on swimming training, several physiologic parameters were examined in eight female high school swimmers before, during and after living and training for six days at 1, 300 meters altitude.Variables included peak heart rate (peakHR), rate of perceived exhaustion (RPE) and blood lactate concentration (BLa) associated with 200m swimming at submaximal and maximal speeds were measured 2-3 days before, during and 1-2 days after altitude exposure. Blood samples were collected before, during and after altitude exposure.On day 1 of altitude exposure, peakHR and RPE at submaximal speeds increased from pre-altitude values while BLa didn't change. At maximal speed, swimming speed and BLa decreased, RPE increased, and peakHR didn't change from pre-altitude.During altitude exposure, for the first three days of altiude exposure for peakHR and for all six days for RPE, the same submaximal speeds elicited greater values than pre-altitude.Post-altitude BLa at submaximal speeds was reduced compared to pre-altitude. Maximal heart rate, RPE, and BLa at maximal speed didn't change pre- to post-altitude. However, mean values of them decreased from pre-altitude.Erythropoietin was elevated above pre-altitude on day 2, and reticulocytes increased post-altitude significantly from pre-altitude.These results indicate that the relative workload increased during the training at 1, 300 meters. There also appeared to be some stimulation for erythropoiesis.In summary, this study found that 1, 300 meters altitude increased the difficulty of swimming training and six days at 1, 300 meters produced mild stimulation of erythropoiesis in these female swimmers

Nutrition Education and Weight Maintenance in Male High-School Swimmers

LEARNING OUTCOME:To examine the effectiveness of nutrition education on weight maintenance of male high-school swimmers during the 14-week swim season. This study examines the effect of nutrition education on weight maintenance of male high-school swimmers throughout the 14-week season. Twenty-nine swimmers from two area high schools participated in this study. The control group from the first high school had 10 swimmers on their team. The second high school, the nutrition education (NE) group, had 19 swimmers on their team. Participants in the control group were weighed at the beginning of the season, and again at the end of the season; no nutritional information was given to this group. The nutrition education (NE) group participated in a nutritional education presentation with a parent, where they also received printed nutritional information including: sport specific nutritional information, snack ideas, and sample training menus. The NE group participants were weighed weekly throughout the 14-week season. Both the control group and the NE group held practices in the same facility, and training sessions were similar in practice time and intensity. The results at the end of the season showed that the control group had a mean weight loss of 1.593 ± 2.58 kg.The NE group results showed a mean gain of 0.579 ± 0.977 kg.The statistical comparison (t-test) of the pre- and post-season weights of both groups showed significant differences (P< 0.05). These results provide evidence that the nutritional education program had a positive effect on male high-school swimmer's ability to maintain weight throughout a rigorous season.

Comparison of Maximal Oxygen Uptakes from the Tethered, the 183- and 457-Meter Unimpeded Supramaximal Freestyle Swims

Nineteen high school swimmers (13 male and 6 female) were subjects in an investigation that compared three methods for determining maximal oxygen uptake (VO2max). Oxygen uptakes were measured during a maximal tethered swim (T), and immediately following 200-yd (183 m) and 500-yd (457 m) unimpeded supramaximal swims from a single 20-s expired gas sample. Oxygen uptakes from the 183-m and 457-m swims correlated highly with those of the T swim (r = 0.94). In addition, VO2s from the 183-m swims were very similar to the VO2s of the 457-m swims (r = 0.96). Mean (+/- SE) VO2max from the T, the 183-m, and the 457-m swims, respectively, were 3.13 (+/- 0.19), 3.20 (+/- 0.19), and 3.20 (+/- 0.17) l/min. There were no significant differences among the three means (p greater than 0.05). This study demonstrates that a single 20-s recovery gas sample from unimpeded supramaximal freestyle swims is an accurate method to determine swimming VO2max.

Pre-Competition Anxiety and Performance in Female High School Swimmers: A Test of Optimal Function Theory

This investigation attempted to test Hanin's theory of optimal function in 15 female high school swimmers. Each swimmer completed the State Anxiety Inventory (STAI) and the Body Awareness Scale (BAS) under the following conditions: I) baseline; II) retrospective recall of "best", "usual", and "worst" performances; III) 24 h prior to an easy and difficult dual meet with instructions to respond as to "how you think you will feel 1 h before the meet"; and IV) 1 h before the meets utilizing the standard ("right now") instructional set. Success was determined in each meet by two methods: 1) objective ratings based on comparisons with the average of times from previous meets; and 2) subjective ratings of performance made by the coach. In the difficult meet significant (P less than 0.01) increases in precompetition anxiety and body awareness occurred, and the correlations between predicted and actual pre-competition were .95 (P less than 0.001) for both anxiety and body awareness. In the difficult meet swimmers subjectively classified as successful were more accurate (P less than 0.05) in predicting precompetition anxiety, and possessed pre-competition anxiety values that were closer to their recall of optimal pre-competition anxiety compared to the unsuccessful swimmers. No comparisons based on the objective classifications were significant, nor were any of the comparisons in the easy meet. The present findings support Hanin's optimal function theory.

Iron deficiency in athletes. Insights from high school swimmers.

Previous studies have indicated a high incidence of nonanemic iron deficiency in high school runners, but little is known regarding participants in other sports. The hematologic and iron status of 30 high school swimmers was assessed at the beginning and end of a competitive swim season. Iron depletion (serum ferritin level less than 12 micrograms/L) was initially present in 46.7% of the girls and none of the boys, yet among those subjects with hypoferritinemia there was no evidence of impaired red blood cell production. Serum haptoglobin levels were normal and did not correlate with serum ferritin levels. No significant change was observed in ferritin, hemoglobin, or haptoglobin concentrations during the course of the season. Dietary intake of iron was poor, particularly in the girls, in whom it averaged 43% of the recommended dietary allowance. Menstrual histories suggested an inverse relationship between the amount of menstrual flow and the serum ferritin level. These findings indicate a high prevalence of nonanemic iron deficiency in female high school swimmers that bears no relationship to swim training. Dietary inadequacies and menstrual blood flow appear to be important contributors to the hypoferritinemia observed in these athletes.

A Mechanical Analysis of the Grab Starting Technique in Swimming

The purpose of this study was to identify the mechanical characteristics of the hands-between-the-feet grab starting technique which contribute to a faster start. Twenty-four high school swimmers performed four trials of a grab start followed by a glide to a distance of 9 m. The results suggested that to obtain a faster start, swimmers should (a) move the center of mass fast in the forward direction while the feet are in contact with the starting block, (b) maximize the force exerted through the feet in the backward direction, and (c) maximize the force exerted through the hands against the starting block in the forward and upward direction.

水泳能力因子構造の性差 : 中学生水泳選手

水泳能力因子構造の性差 : 中学生水泳選手