JROTC as a Substitute for PE: Really?

Purpose: Even though physical education (PE) is an evidence-based strategy for providing and promoting physical activity, alternative programs such as the Junior Reserve Officer Training Corps (JROTC) are commonly substituted for PE in many states. The purpose of this study was to compare student physical activity and lesson contexts during high school PE and JROTC sessions. Method: The System for Observing Fitness Instruction Time was used to assess PE and JROTC sessions (N = 38 each) in 4 high schools that provided both programs. Data were analyzed using t tests, negative binomial regression, and logistic regression. Results: Students engaged in significantly more moderate-to-vigorous physical activity during PE than during JROTC sessions and they were significantly less sedentary. Significant differences between the 2 program types were also found among lesson contexts. Conclusions: PE and JROTC provide substantially different content and contexts, and students in these programs engage in substantially different amounts of moderate-to-vigorous physical activity. Students in JROTC, and perhaps other alternative programs, are less likely to accrue health-supporting physical activity and engage in fewer opportunities to be physically fit and motorically skilled. Policies and practices for providing substitutions for PE should be carefully examined.     

Urban Minority Ninth-Grade Students' Health-Related Fitness Knowledge

The purpose of the study was to examine Hispanic and other minority ninth-grade students' health-related fitness (HRF) knowledge, using FitSmart, a standardized test for high school students. The test consisted of 50 weighted multiple choice items, measuring six subcontent components. Means and standard deviations of the overall scores and the subcontent scores were computed. The findings suggested that students demonstrated mastery of one subcontent component but failed to meet passing values for all other subcontents and overall HRF knowledge. Female students outscored their male counterparts, but there was no difference for ethnicity. More efforts are needed to ensure that Hispanic and other minority high school students master fundamental HRF knowledge.     

Analysis of lower limb internal kinetics and electromyography in elite race walking

Abstract

The aim of this study was to analyse lower limb joint moments, powers and electromyography patterns in elite race walking. Twenty international male and female race walkers performed at their competitive pace in a laboratory setting. The collection of ground reaction forces (1000 Hz) was synchronised with two-dimensional high-speed videography (100 Hz) and electromyography of seven lower limb muscles (1000 Hz). As well as measuring key performance variables such as speed and stride length, normalised joint moments and powers were calculated. The rule in race walking which requires the knee to be extended from initial contact to midstance effectively made the knee redundant during stance with regard to energy generation. Instead, the leg functioned as a rigid lever which affected the role of the hip and ankle joints. The main contributors to energy generation were the hip extensors during late swing and early stance, and the ankle plantarflexors during late stance. The restricted functioning of the knee during stance meant that the importance of the swing leg in contributing to forward momentum was increased. The knee flexors underwent a phase of great energy absorption during the swing phase and this could increase the risk of injury to the hamstring muscles.     

Leisure Attitudes of Varsity Athletes vs. NonVarsity Athletes

Abstract

Students (N = 104) enrolled in four low fitness, one middle fitness, and one high fitness class in basic physical education classes at the University of Connecticut participated in a 4-week program of isometric exercises done with an adjustable nylon belt which was stabilized against various body segments. Low, middle, and high fitness classes were compared in the amount of improvement made in the 5 items in which significant gains had been made. The MWF classes which did 30 min. of isometric exercises for 12 class meetings were compared to the TTh classes which met for 8 class meetings and which did the same isometric exercise program and in addition did stretching exercises and ran a mile.

When all groups were treated together, mean gains of 1.1 in. in the vertical jump, .74 sec. in the agility run, .17 sec. in the 30-yd. dash, 151.9 lb. in the leg lift, and 57.0 lb. in the back lift were made. These were all significant at the 0.005 to the 0.0005 level. Small but significant gains were made in right and left grip, the Fait endurance hang, and the 380-yd. run. The low fitness classes made greater improvements in the leg lift, the vertical jump, and the agility run than did the middle or high fitness groups. The high fitness class made greater improvements in the back lift and in the 30-yd. dash than did the low or middle fitness classes. The classes which did only isometric exercises for a half-hour three times each week for 4½ weeks made greater mean gains in the vertical jump, the agility run, the 30-yd. dash and the back lift than did the classes which met for 60-min. periods twice each week for 4½ weeks and did stretching exercises and running in addition to the isometric exercises. However, the latter made greater gains in the leg lift.     

Effect of loading on peak power of the bar,body, and system during power cleans,squats, and jump squats

Abstract

Nine males (age 24.7 ± 2.1 years, height 175.3 ± 5.5 cm, body mass 80.8 ± 7.2 kg, power clean 1-RM 97.1 ± 6.36 kg, squat 1-RM = 138.3 ± 20.9 kg) participated in this study. On day 1, the participants performed a one-repetition maximum (1-RM) in the power clean and the squat. On days 2, 3, and 4, participants performed the power clean, squat or jump squat. Loading for the power clean ranged from 30% to 90% of the participant's power clean 1-RM and loading for the squat and jump squat ranged from 0% to 90% of the participant's squat 1-RM, all at 10% increments. Peak force, velocity, and power were calculated for the bar, body, and system (bar + body) for all power clean, squat, and jump squat trials. Results indicate that peak power for the bar, body, and system is differentially affected by load and movement pattern. When using the power clean, squat or jump squat for training, the optimal load in each exercise may vary. Throwing athletes or weightlifters may be most concerned with bar power, but jumpers or sprinters may be more concerned with body or system power. Thus, the exercise type and load vary according to the desired stimulus.     

Effect of sand versus grass training surfaces during an 8-week pre-season conditioning programme in team sport athletes

Abstract

This study compared the use of sand and grass training surfaces throughout an 8-week conditioning programme in well-trained female team sport athletes (n = 24). Performance testing was conducted pre- and post-training and included measures of leg strength and balance, vertical jump, agility, 20 m speed, repeat speed (8 × 20 m every 20 s), as well as running economy and maximal oxygen consumption (VO_2max). Heart rate (HR), training load (rating of perceived exertion (RPE) × duration), movement patterns and perceptual measures were monitored throughout each training session. Participants completed 2 × 1 h conditioning sessions per week on sand (SAND) or grass (GRASS) surfaces, incorporating interval training, sprint and agility drills, and small-sided games. Results showed a significantly higher (P < 0.05) HR and training load in the SAND versus GRASS group throughout each week of training, plus some moderate effect sizes to suggest lower perceptual ratings of soreness and fatigue on SAND. Significantly greater (P < 0.05) improvements in VO_2max were measured for SAND compared to GRASS. These results suggest that substituting sand for grass training surfaces throughout an 8-week conditioning programme can significantly increase the relative exercise intensity and training load, subsequently leading to superior improvements in aerobic fitness.     

Physiological Effects of Deep Water Running following a Land-Based Training Program

Abstract

The purpose of this study was to examine differences in knowledge representation and problem solutions in expert and novice youth baseball players. Ninety-four players in two age divisions, 7–8 years of age and 9–10 years of age, were assigned to three levels of expertise: high; average; and low skilled. Each subject participated in an interview session to elicit knowledge representation and solutions to five different defensive game situations. Interviews were transcribed and analyzed for content, solution to the problem, errors in problem solution, and qualitative trends. The frequency of advanced solutions to each of the five situations were analyzed in separate chi-square tests for age and expertise. Differences among the levels of expertise were found for the accuracy of solutions to three complex situations. Age was significant for only one situation. Patterns of knowledge content accessed during advanced and less advanced responses indicated both experts and novices were in a beginning stage of developing baseball knowledge structures. Errors in problem solutions indicated children had difficulty monitoring critical conditions and making correct inferences. Players' and teammates' ability to execute baseball skills seemed to influence the content and structure of tactical knowledge accessed during problem solution.     

Report and Recommendations of the National Committee on Aquatic Leadership

Abstract

Five subjects were tested three times in each of three static and three phasic work tests involving leg extensions in the semi-reclining position. Oxygen uptake, net oxygen consumption, ventilation rate, pulse rate, and systolic and diastolic blood pressures were consistently higher in phasic work than in static effort with a comparable resistance. The patterns of systolic and diastolic blood pressure and pulse rate response and recovery did not seem to differ in the two modes of work. While the ventilation rate—oxygen uptake relationship was similar in both forms of effort, the pulse rate—oxygen uptake relationship differed in that the static pulse exceeded the phasic rate at a comparable level of oxygen uptake.     

IBM's Chess Players: On AI and Its Supplements

This article investigates the ways in which the reporting of technological developments in artificial intelligence (AI) can serve as occasions in which Occidental modernity's cultural antinomies are played out. It takes as its reference point the two chess tournaments (in 1996 and 1997) between the then world champion Gary Kasparov and the IBM dedicated chess computers Deep Blue and Deeper Blue and shows how these games of chess came to be seen as an arena where fundamental issues pertaining to human identity were contested. The article considers the dominant framing of these encounters in terms of a conflict between two opposed categories—“human” and “machine”—and argues the essential role of human agency, the human supplement, in the performances of machine intelligence.