The reliability of isoinertial force–velocity–power profiling and maximal strength assessment in youth

The purpose of this study was to quantify the inter-session reliability of force–velocity–power profiling and estimated maximal strength in youth. Thirty-six males (11–15 years old) performed a ballistic supine leg press test at five randomized loads (80%, 100%, 120%, 140%, and 160% body mass) on three separate occasions. Peak and mean force, power, velocity, and peak displacement were collected with a linear position transducer attached to the weight stack. Mean values at each load were used to calculate different regression lines and estimate maximal strength, force, velocity, and power. All variables were found reliable (change in the mean [CIM] = ? 1 to 14%; coefficient of variation [CV] = 3–18%; intraclass correlation coefficient [ICC] = 0.74–0.99), but were likely to benefit from a familiarization, apart from the unreliable maximal force/velocity ratio (CIM = 0–3%; CV = 23–25%; ICC = 0.35–0.54) and load at maximal power (CIM = ? 1 to 2%; CV = 10–13%; ICC = 0.26–0.61). Isoinertial force–velocity–power profiling and maximal strength in youth can be assessed after a familiarization session. Such profiling may provide valuable insight into neuromuscular capabilities during growth and maturation and may be used to monitor specific training adaptations.     

Caffeine lowers perceptual response and increases power output during high-intensity cycling

The aim of this study was to determine the effects of caffeine ingestion on a ‘preloaded’ protocol that involved cycling for 2?min at a constant rate of 100% maximal power output immediately followed by a 1-min ‘all-out’ effort. Eleven male cyclists completed a ramp test to measure maximal power output. On two other occasions, the participants ingested caffeine (5?mg?·?kg^?1) or placebo in a randomized, double-blind procedure. All tests were conducted on the participants' own bicycles using a Kingcycle? test rig. Ratings of perceived exertion (RPE; 6–20 Borg scale) were lower in the caffeine trial by approximately 1 RPE point at 30, 60 and 120?s during the constant rate phase of the preloaded test (P?<0.05). The mean power output during the all-out effort was increased following caffeine ingestion compared with placebo (794±164 vs 750±163?W; P?=?0.05). Blood lactate concentration 4, 5 and 6?min after exercise was also significantly higher by approximately 1?mmol?·?l^?1 in the caffeine trial (P?<0.05). These results suggest that high-intensity cycling performance can be increased following moderate caffeine ingestion and that this improvement may be related to a reduction in RPE and an elevation in blood lactate concentration.     

Body Fatness and Performance Differences between Men and Women

The purpose of this study was to determine the extent to which the mean difference in performance between men and women on selected physical performance tests was related to the sex difference in body fatness. Percent total body fat (% fat) estimated from skinfold thickness measures and performances on the modified pull-up, vertical jump, 50-yard dash, and 12-minute-run tests were measured on 55 male and 55 female college students. Males had significantly less fat and performed significantly better than females on each of the performance tests. Mean differences were 8.2% fat, 20.0 modified pull-ups, 20.8 cm on the vertical jump, 1.3 seconds on the 50-yard dash, and 590 m on the 12-minute run. Linear regression equations predicting performance scores from % fat within the groups of men and women indicated that if body fatness in men and women were similar, performance differences would be reduced, on the average, by 7 modified pull-ups, 4 cm on the vertical jump, .5 seconds on the 50–yard dash, and 146 m on the 12-minute run. These expected changes in performance were 36%, 19%, 38%, and 25% of the mean sex difference in performance on the four physical performance tests, respectively. It was concluded that greater body fatness is one characteristic that partly explains why women, on the average, do not perform as well as men on strenuous tasks requiring movement of the body weight. The sex-specific difference in body fatness should be one factor considered in establishing separate occupational and athletic performance expectations for men and women.     

Relative Effects of Isokinetic and Plyometric Training on Vertical Jumping Performance

Forty-eight volunteer males were randomly assigned to one of three groups. Group I trained with isokinetic exercises, Group II trained with plyometric exercises, and Group III was the control. Subjects in the training groups trained three times per week for 8 weeks. The isokinetic group performed three sets of 10 repetitions per set of leg presses each training session. The plyometric group performed three sets of 10 repetitions per set of depth jumps from a height of 34 inches, with added resistance beginning with weeks 3, 5, and 7 of 10, 15, and 20 pounds, respectively. Prior to and at the end of the training period, all subjects were given a vertical jump-and-reach test. Covariance analysis was used to compare posttest scores with the effect of pretest differences removed. Results showed both training groups improved significantly in vertical jump capacity; however, no significant difference existed between training groups.     

Body Fatness and Motor Performance During Preadolescence

Abstract

Performance differences between males and females have been attributed to both biological and cultural factors, although the relative significance of each has not been ascertained. Differences in body fatness between males and females has been frequently mentioned as one biological factor responsible for variations in physical performance. In children, it has been shown that boys exhibit slightly higher performance levels than girls until adolescence, when the differences favoring the boys become greater. The purpose of this study was to investigate the relationship between selected physical performance tests and body fatness in preadolescent boys and girls. Measures of age, height, weight, skinfold thicknesses at two sites, and performance scores on the vertical jump, standing broad jump, modified pullup, 40-yard dash, and 400-yard run were obtained on 563 elementary school children. The results of a one-way ANOVA indicated that there was a significant difference between boys and girls on all of the physical performance tests. Although the boys were slightly taller and heavier and scored better than the girls on the performance tests, there was no significant difference between the sexes in the sum of two skinfolds. Separate regression equations for the sum of two skinfolds by performance on each test indicated that, with the exception of the modified pullup test, body fatness was only marginally related to performance. These findings indicated that, although inversely related to the ability to move the total body weight, body fatness was of minimal importance in explaining performance differences between young boys and girls.     

Yearly Changes in the Body Composition and Muscular Strength of High School Wrestlers

Abstract

The purpose of this investigation was to determine the yearly changes in body composition as well as absolute and relative isokinetic forearm flexion and extension strength of high school wrestlers. Evaluations of body composition (underwater weighing) were performed on 27 high school wrestlers prior to three consecutive seasons. In addition, isokinetic forearm flexion and extension strength values at 180°/s (Cybex II) were available for 20 of the subjects. The mean ages at the times of laboratory testing were 15.5 (± .5), 16.5 (± .5), and 17.5 (± .5) years. Repeated measures ANOVA or ANCOVA with Tukey post-hoc comparisons were used to locate significant (p<.05) differences across age for height, body weight, relative fat, body density, fat weight, fat-free weight, absolute muscular strength, and muscular strength covaried for body weight and fat-free weight. There were yearly increases in all variables except fat weight, forearm flexion covaried for fat-free weight and forearm extension covaried for fat-free weight. The results of this study indicated that the improved wrestling performance and the increase in weight classification which normally occurs during high school are, in part, a function of yearly changes in body composition and muscular strength.     

The relationship between student engagement with online content and achievement in a blended learning anatomy course

Blended learning has become increasingly common in higher education. Recent findings suggest that blended learning achieves better student outcomes than traditional face‐to‐face teaching in gross anatomy courses. While face‐to‐face content is perceived as important to learning there is less evidence for the significance of online content in improving student outcomes. Students enrolled in a second‐year anatomy course from the physiotherapy (PT), exercise physiology (EP), and exercise science (ES) programs across two campuses were included (n = 500). A structural equation model was used to evaluate the relationship of prior student ability (represented by grade in prerequisite anatomy course) and final course grade and whether the relationship was mediated by program, campus or engagement with the online elements of the learning management system (LMS; proportion of documents and video segments viewed and number of interactions with discussion forums). PT students obtained higher grades and were more likely to engage with online course materials than EP and ES students. Prerequisite grade made a direct contribution to course final grade (P < 0.001) but was also mediated by engagement with LMS videos and discussion forums (P < 0.001). Student learning outcomes in a blended anatomy course can be predicted the by level of engagement with online content. Anat Sci Educ 11: 471–477. © 2017 American Association of Anatomists.     

Contact,culture and context: evidence from mixed faith schools in Northern Ireland and Israel

This paper compares the concept of mixed faith/cultural education in Northern Ireland and Israel. It is primarily concerned with the processes that these ‘integrated’ schools adopt in their quest to improve relations between divided ethnic groups. Drawing on qualitative data collected in two mixed religion primary schools in each jurisdiction the paper shows that the schools' existing cultural norms act as important mediating influences on the way that inter‐group relationships are constructed. The paper concludes that attention needs to be paid to both the policy context and the culture if contact initiatives are to be successful.     

Market structure and institutional position in geographic market segments

Marketing and market research have formally entered the world of college recruiting in recent years, and market structure, market segments, and institutional positioning are concepts that have gained currency among academic marketers. In this paper a variety of analytic techniques—comparisons of frequency distributions, cross-tabulations, multidimensional scaling, and regression analysis—are used to examine the structure of a college's competition and institutional market position in relation to students' market behavior—the decision to accept a college's offer of admission. The analysis focuses on how these phenomena vary between two geographic market segments. Brief mention is made of some of the marketing implications of the data.An earlier version of this paper was presented at the Annual Forum of the Association for Institutional Research, Houston, Texas, May 1978.