The effects of acute carbohydrate and caffeine feeding strategies on cycling efficiency

To assess the effect of carbohydrate and caffeine on gross efficiency (GE), 14 cyclists (V?O_2max 57.6 ± 6.3 ml.kg^?1.min^?1) completed 4 × 2-hour tests at a submaximal exercise intensity (60% Maximal Minute Power). Using a randomized, counter-balanced crossover design, participants consumed a standardised diet in the 3-days preceding each test and subsequently ingested either caffeine (CAF), carbohydrate (CHO), caffeine+carbohydrate (CAF+CHO) or water (W) during exercise whilst GE and plasma glucose were assessed at regular intervals (~30 mins). GE progressively decreased in the W condition but, whilst caffeine had no effect, this was significantly attenuated in both trials that involved carbohydrate feedings (W = ?1.78 ± 0.31%; CHO = ?0.70 ± 0.25%, p = 0.008; CAF+CHO = ?0.63 ± 0.27%, p = 0.023; CAF = ?1.12 ± 0.24%, p = 0.077). Blood glucose levels were significantly higher in carbohydrate ingestion conditions (CHO = 4.79 ± 0.67 mmol·L^?1, p < 0.001; CAF+CHO = 5.05 ± 0.81 mmol·L^?1, p < 0.001; CAF = 4.46 ± 0.75 mmol·L^?1; W = 4.20 ± 0.53 mmol·L^?1). Carbohydrate ingestion has a small but significant effect on exercise-induced reductions in GE, indicating that cyclists’ feeding strategy should be carefully monitored prior to and during assessment.     

Knowledge about Puberty and Sexual Development in 11‐16 Year‐olds: implications for health and sex education in schools

Knowledge is an important but largely neglected variable in sex education research. This study aimed to develop a measure to assess young people's knowledge about puberty and sexual development, and to examine knowledge in relation to age, gender and school. The main results of the study were that knowledge increased more between age 11/12 and 13/14 than between 13/14 and 15/16, girls knew more than boys at every age, and there were few differences in knowledge between the four schools involved in the study. The research has a number of implications for sex education in schools. First, it was found that even by age 15‐16 some young people lack information which is essential if they are to avoid unwanted pregnancy. Second, it may be that boys and girls need to be taught separately to enable the different needs of each gender to be addressed. Third, young people know more about some aspects of puberty and sexual development than others, and there are particular times when knowledge develops most rapidly. Giving teachers this information could help them to target areas of particular ignorance. The questionnaire developed to assess knowledge proved to be accurate and reliable, and a measure that is straightforward to score and analyse. As such, it has considerable potential for use in the classroom.     

Broadcast Programming and Management

George Dessart's Television in the Real World: A Case Study Course in Broadcast Management (New York: Hastings House, 1978—$16.50/8.95)

Howard W. Coleman's Case Studies in Broadcast Management (New York: Hastings House, 1978—$10.75/4.95)

Joseph S. Johnson and Kenneth K. Jones' Modern Radio Station Practices (Belmont, Calif.: Wadsworth Publishing Co., 1978—$12.95)

Charles Clift and Archie Greer, eds. Broadcast Programming: The Current Perspective (University Press of America, 4710 Auth Place, S.E., Washington, D.C. 20023— price not given, paper)

Rose K. Goldsen's The Show and Tell Machine: How Television Works and Works You Over (New York: Dial Press, 1978—$10.00)

Ben Logan, ed. Television Awareness Training for New Awareness, New Decisions, New Action (Media Action Research Center, Inc., 475 Riverside Drive, New York, N.Y. 10027—$8.50, paper, including mailing)

Lee Polk and Lda LeShan's The Incredible Television Machine (New York: Macmillan, 1977—$6.95)

Mary Livingstone Benny, Hilliard Marks and Marcia Borie's Jack Benny (New York: Doubleday, 1978—$10.00)     

The effects of caffeine ingestion on performance time,speed and power during a laboratory-based 1 km cycling time-trial

Abstract

There is little published data in relation to the effects of caffeine upon cycling performance, speed and power in trained cyclists, especially during cycling of ～60 s duration. To address this, eight trained cyclists performed a 1 km time-trial on an electronically braked cycle ergometer under three conditions: after ingestion of 5 mg · kg^?1 caffeine, after ingestion of a placebo, or a control condition. The three time-trials were performed in a randomized order and performance time, mean speed, mean power and peak power were determined. Caffeine ingestion resulted in improved performance time (caffeine vs. placebo vs. control: 71.1 ± 2.0 vs. 73.4 ± 2.3 vs. 73.3 ± 2.7 s; P = 0.02; mean ± s). This change represented a 3.1% (95% confidence interval: 0.7–5.6) improvement compared with the placebo condition. Mean speed was also higher in the caffeine than placebo and control conditions (caffeine vs. placebo vs. control: 50.7 ± 1.4 vs. 49.1 ± 1.5 vs. 49.2 ± 1.7 km · h^?1; P = 0.0005). Mean power increased after caffeine ingestion (caffeine vs. placebo vs. control: 523 ± 43 vs. 505 ± 46 vs. 504 ± 38 W; P = 0.007). Peak power also increased from 864 ± 107 W (placebo) and 830 ± 87 W (control) to 940 ± 83 W after caffeine ingestion (P = 0.027). These results provide support for previous research that found improved performance after caffeine ingestion during short-duration high-intensity exercise. The magnitude of the improvements observed in our study could be due to our use of sport-specific ergometry, a tablet form and trained participants.     

An examination of the planar nature of golf club motion in the swings of experienced players

Abstract

The golf swing has been modelled as a planar movement, but recent findings suggest that the upper limbs and golf club do not move in a single plane. However, the idea that the club alone can be swung in a single inclined plane has not been investigated mathematically. The aims of this study were to determine whether a single plane could be fitted to club motion, and if this plane varied for different clubs. Ten golfers (handicap 1 – 5) performed repeated, consistent swings with three clubs (driver, 5-iron, and pitching wedge). The motion of each club during the downswing was fitted to a single plane. The fit of the plane varied between golfers and clubs (r ² = 0.871 – 0.995, root mean square residual = 44.9 – 166.2 mm). Mean angles of the plane to the reference horizontal Z axis (driver: 125.5°, s = 3.0; 5-iron: 117.1°, s = 3.0; wedge: 113.6°, s = 2.7) and target line axis (driver: ?7.8°, s = 5.9; 5-iron: ?4.9°, s = 5.7; wedge: ?5.9°, s = 6.0) were significantly (P < 0.05) different. Further analysis revealed a single plane was more appropriate for some participants than others, but that it might be neither desirable nor possible in some cases.     

Correlates of simulated hill climb cycling performance

The aim of this study was to assess the relationship between several commonly used aerobic and anaerobic cycle ergometer tests and performance during a treadmill cycling hill climb. Eight competitive cyclists (age 27+/-7 years; body mass 73.2+/-5.2 kg; height 177+/-6 cm; mean +/- s) completed six tests in random order: a lactate minimum test; a Wingate anaerobic power test; and two 6-km climbs at 6% and two 1-km climbs at 12% gradient performed on a motorized treadmill. The mean times and power outputs for the 6-km and 1-km climbs were 16:30+/-1:08 min: s and 330+/-17.8 W, and 4:19+/-0:27 min: s and 411+/-24.4 W, respectively. The best individual predictor of 6-km and 1-km performance times was the time for the corresponding climb at the other distance (r = 0.97). The next strongest predictor of both hill climb performances was the average power produced during the Wingate test divided by body mass. Stepwise regression analysis showed that the two variables contributing most to the prediction equation for both climbs were the Wingate average power per unit of body mass and maximal aerobic power divided by total mass (rider + bike), which together accounted for 92 and 96% of the variability in the 6-km and 1-km climbs. In conclusion, among competitive cyclists, the Wingate average power per unit of body mass was the best single predictor of simulated cycling hill climb performance at the distance and gradient used.     

Teacher perceptions of differences among elementary students with and without learning disabilities in referred samples

Current referral and identification procedures for students with learning disabilities (LD) have been criticized on conceptual and procedural dimensions, including difficulties in operationalizing the definition and in making eligibility decisions that are data based. Recognizing these difficulties, the Texas Education Agency appointed a task force to examine various issues associated with the identification, assessment, and programming of students with LD. Task force members recognized the need to identify classroom behaviors that differentiate students with LD from their non-disabled peers. Two scales of 83 items each were devised and piloted in 70 school districts. Five significant factors or subscales were identified through discriminant factor analyses. Two subscales and 18 individual items discriminate students later classified as LD and those referred but not subsequently classified as LD. Results are discussed, with implications for further investigation of behaviors that distinguish students with and without LD.     

A Study of the Relationship Between Child Care Providers' Use of HIV/AIDS Information Sources, Knowledge of HIV/AIDS, and Attitudes Toward Caregiving Policies

The human immunodeficiency virus (HIV), the virus that leads to acquired immunodeficiency syndrome (AIDS), has been a part of American society for over two decades. Today, HIV/AIDS touches all demographic groups, including young children. It is for this reason that child care providers need to be informed about HIV/AIDS and related policies that impact their work with young children. The purpose of this study was to examine child care providers' use of different HIV/AIDS information sources in relationship to their knowledge about HIV/AIDS and their response to common childhood behaviors and classroom situations involving an HIV-infected child. Results suggest that different types of information sources are associated with different aspects of providers' knowledge about and response to pediatric HIV/AIDS. Implications for the planning and delivery of HIV/AID training involving child care providers are discussed.