Canadian journal of applied sport sciences. Journal canadien des sciences appliquees au sport最新文献

This article is divided into two parts: Part 1 consists of the position stand of The Canadian Association of Applied Sport Sciences on the involvement of children in competitive sports, and Part II presents scientific background and rationale pertinent to the position statements. Each part is divided into major categories reflecting the multi-disciplinary concerns of the participation of pre- and post-pubescent children in sport situations at all levels. Psychological considerations focus on the child learning a sense of competence and control through sport participation. Success in a sport should not be based solely on winning, but on one's own performance and attained goals. Sport involvement can provide one important avenue for a child's social development. Non-aggressive behaviour and a constructive problem-solving approach should be encouraged. Any form of discrimination towards sport participation or competition should be discouraged. From the physiological and medical point of view, it should be recognized that each child is different in his/her response and tolerance to exercise due to a great range of variability in growth rates, anthropometric indices, gender and state of health, even in children of a similar chronological age. Younger prepubertal children should be encouraged to participate in a wide variety of motor skills, whereas older post-pubertal children can become more specialized in their training and sport participation. A child's performance and adaptation to training should not be directly compared to an adult's as significant differences exist, especially during the years of accelerated growth. Environmental exercise tolerance is also more limited to children than adults. In younger children repetitive heavy loading of the musculoskeletal system should be approached with caution. With proper equipment design and usage, and rule modifications, serious injuries can be avoided. Medical disabilities should be evaluated on an individual basis and should not necessarily preclude a child's participation. Teachers, parents and coaches should have a thorough understanding of the implications of children involved in sports and adhere to the recommendations reviewed in this statement.

This study investigated the effects of stride length (SL) manipulation on racewalking economy in 7 competitive racewalkers. Following two test sessions in which VO2 max and freely-chosen stride length (FCSL) were determined, each subject completed 6-min racewalking bouts at five randomly-ordered SL conditions (FCSL and -10%, -5%, +5%, and +10% of leg length from the FCSL) while walking at a velocity approximately equal to their 10 km training pace. Actual and predicted group mean VO2 values for the five SL conditions indicated that the subjects were most economical walking at the FCSL, with progressively higher energy costs manifested at the +5% and -5% and the +10% and -10% leg length conditions, respectively. A mean absolute difference in VO2 of 0.6 ml X kg-1 X min-1 was observed between subjects' FCSL and optimal SL. Linked with this deviation in VO2 was a mean absolute SL difference of 3.2 cm (3.6% of mean leg length). These data support the hypothesis that trained subjects select locomotion patterns that are nearly optimal in terms of the aerobic demands.

The suitability of the Wingate Anaerobic Test (WAT40) as a laboratory measure of anaerobic capacity (AnCap) and power (AnPow) of ice hockey players was tested against the Reed Repeat Sprint Skate-RSS (1979) and the Sargeant Anaerobic Skate (SAS40). Twenty-four university and Junior A players (20.2 +/- 1.6 years), assigned by random draw, performed the three tests over a seven day period. Blood lactate taken from an unwarmed finger tip was used to assess work intensity. The AnCap (7.7 +/- 0.2 Watts X kg-1) and AnPow (10.1 +/- 0.2 Watts X kg-1) for WAT40 were significantly lower (p less than 0.05) than for RSS (AnCap 9.3 +/- 0.8 Watts X kg-1; AnPow 11.5 +/- 1.1 Watts X kg-1) and SAS40 (AnCap 9.7 +/- 0.8 Watts X kg-1; AnPow 11.9 +/- 1.8 Watts X kg-1). SAS40 was significantly higher (p less than 0.05) than RSS for both AnCap and AnPow. The RSS (r = 0.96; ME 4.5%) and SAS40 (r = 0.97; ME = 3.6%) showed excellent test-retest reliability and reproducibility for AnCap but were only fair on AnPow (RSS: r = 0.73; ME = 10.7%; SAS40: r = 0.65; ME = 18.4%). While the correlations among the tests (AnCap: SAS40 vs WAT40, r = 0.73; RSS vs WAT40, r = 0.69) were significant (p less than 0.05), the highest predictive capability estimate (r2) was only 53.3%. The correlations for blood lactates (WAT40: 10.8 +/- 1.5 mmol X l-1; SAS40: 10.7 +/- 1.9 mmol X l-1; RSS: 11.5 +/- 1.6 mmol X l-1) were not significant. Based upon the particular protocol used, the laboratory test WAT40 does not demonstrate a high relationship with on-ice measures of AnCap and AnPow in this group of ice hockey players.

The present study sought to examine the relationship between selected psychological traits as measured by the Institute for Personality and Ability Testing (IPAT) 16 PF inventory and fear of success as measured by the Fear of Success Scale (FOSS). The subjects were 36 Senior elite wrestlers (age 20-25) who were invited to the Colorado Springs Olympic Training Center to prepare for an up-coming inter-national competition. A stepwise multiple regression analysis revealed that the following 16 PF factors predicted fear of success (p less than .05): IPAT-Q4, IPAT-L, IPAT-E, and IPAT-O. The multiple R was .75 and the R2 was 57.78%. Interpretation of the results suggest that while this sample of Senior elite wrestlers generally exhibit extremely low fear of success scores, athletes who are tense, frustrated, apprehensive, submissive, humble, and trusting tend to be more fearful of the consequences of success than those who are relaxed, unfrustrated, self-assured, assertive, competitive, and suspecting.

Two cases of isolated injury to the posterior cruciate ligament of the knee are presented. These injuries both occurred in elite wrestlers, members of the Canadian Pan American Team. The mechanism of injury was identical in both cases--the ligament rupture being a result of forced flexion with combined internal rotation of the tibia on femur. A review of the literature is added with a suggestion for conservative treatment as the initial and perhaps definitive management for this problem.

There has been an improvement in Canadian freestyle wrestling performance over the past five years. Medals are now being won at World and Olympic competitions. The present investigation provides baseline physiological data which have been used in the prescription of individual training programs for these athletes. This information is also available to the coaches and contributes to the strategy for individual matches. Generally, the Canadian wrestlers have a physiological profile similar to elite wrestlers from other countries. Maximal aerobic power is comparable to or greater than previously reported values. Needle biopsies reveal exceptionally large fast twitch fibre areas in vastus lateralis. However, anaerobic capacity and upper body strength are less than values reported for other elite athletes.

Studies of serum lipids in women training are inconclusive and have not considered menstrual hormones. Women (N = 8, 20-25 yrs) were studied over 3 consecutive cycles. The first cycle was a control cycle and then they trained for two cycles (3 times/wk for 30 min/day at 60% max HR reserve). Blood samples were drawn 5 to 7 days after the onset of menses (M) and mid-luteal (L) of all three cycles. Cycle phase (i.e. M vs L) did not influence total cholesterol or HDL cholesterol but triglyceride (TG) was higher (p less than 0.05) at M. The training period (65 +/- 7.5 days (SD) resulted in a significant (p less than 0.05) increase in VO2 max and decrease in resting HR. Training resulted in a decline (p less than 0.05) in HDL cholesterol from M1 to M2 (1.32 +/- 0.26 to 1.12 +/- 0.23 mmol/L) and a return to control by M3 (1.36 +/- 0.37 mmol/L). Training also resulted in TG declining (p less than 0.05) from L1 to L2 and from M2 to M3. Cycle phase only affected TG. Exercise training, however, resulted in a decline in TG and an initial decline in HDL cholesterol and a return to control levels during the second month of training.

The purpose of the present study is to determine the physiological and metabolic variations during and after an exhaustive exercise in different thermal conditions (0 degree C and 20 degrees C). For the eleven experimental subjects, the maximal power output is the same at 0 degrees C and 20 degrees C: 330 +/- 30 W (Mean +/- s). The heart rate is lower (bradycardia) at rest, exhaustion, and recovery. However, these differences are only significant (p less than 0.05) at exhaustion. The oxygen consumption and pulmonary ventilation is higher at 0 degree C in comparison with the measurements at 20 degrees C. The blood lactate concentrations are significantly lower at 0 degree C and we observe the inverse phenomenon for the bicarbonates. The bases excess was significant at 4, 6 and 10th minute of recovery time. These values are higher for the measurements taken at 0 degree C. The results have shown that the cold stress after an exhaustive exercise and during recovery, can induce a physiological and metabolic response unlike of those at 20 degrees C.