Effects of coffee and caffeine anhydrous on strength and sprint performance     

Eric T. Trexler  Erica J. Roelofs  Katie R. Hirsch  Meredith G. Mock 《European Journal of Sport Science》2016,16(6):702-710

Caffeine and coffee are widely used among active individuals to enhance performance. The purpose of the current study was to compare the effects of acute coffee (COF) and caffeine anhydrous (CAF) intake on strength and sprint performance. Fifty-four resistance-trained males completed strength testing, consisting of one-rep max (1RM) and repetitions to fatigue (RTF) at 80% of 1RM for leg press (LP) and bench press (BP). Participants then completed five, 10-second cycle ergometer sprints separated by one minute of rest. Peak power (PP) and total work (TW) were recorded for each sprint. At least 48 hours later, participants returned and ingested a beverage containing CAF (300?mg flat dose; yielding 3–5?mg/kg bodyweight), COF (8.9?g; 303?mg caffeine), or placebo (PLA; 3.8?g non-caloric flavouring) 30 minutes before testing. LP 1RM was improved more by COF than CAF (p?=?.04), but not PLA (p?=?.99). Significant interactions were not observed for BP 1RM, BP RTF, or LP RTF (p?>?.05). There were no sprint?×?treatment interactions for PP or TW (p?>?.05). 95% confidence intervals revealed a significant improvement in sprint 1 TW for CAF, but not COF or PLA. For PLA, significant reductions were observed in sprint 4 PP, sprint 2 TW, sprint 4 TW, and average TW; significant reductions were not observed with CAF or COF. Neither COF nor CAF improved strength outcomes more than PLA, while both groups attenuated sprint power reductions to a similar degree. Coffee and caffeine anhydrous may be considered suitable pre-exercise caffeine sources for high-intensity exercise.  相似文献   

Body composition of female road and track endurance cyclists: Normative values and typical changes     

Eric C. Haakonssen  Martin Barras  Louise M. Burke  David G. Jenkins  David T. Martin 《European Journal of Sport Science》2016,16(6):645-653

The aims of this study were to describe normative values and seasonal variation of body composition in female cyclists comparing female road and track endurance cyclists, and to validate the use of anthropometry to monitor lean mass changes. Anthropometric profiles (seven site skinfolds) were measured over 16 years from 126 female cyclists. Lean mass index (LMI) was calculated as body weight?×?skinfolds^?x. The exponent (x) was calculated as the slope of the natural logarithm of body weight and skinfolds. Percentage changes in LMI were compared to lean mass changes measured using dual-energy X-ray absorptiometry (DXA) in a subset of 25 road cyclists. Compared to sub-elite and elite cyclists, world class cyclists were (mean [95% CI]) 1.18?kg [0.46, 1.90] and 0.60?kg [0.05, 1.15] lighter and had skinfolds that were 7.4?mm [3.8, 11.0] and 4.6?mm [1.8, 7.4] lower, respectively. Body weight (0.41?kg [0.04, 0.77]) and skinfolds (4.0?mm [2.1, 6.0]) were higher in the off-season compared to the early-season. World class female road cyclists had lower body weight (6.04?kg [2.73, 9.35]) and skinfolds (11.5?mm [1.1, 21.9]) than track endurance cyclists. LMI (mean exponent 0.15 [0.13, 0.18]) explained 87% of the variance in DXA lean mass. In conclusion, higher performing female cyclists were lighter and leaner than their less successful peers, road cyclists were lighter and leaner than track endurance cyclists, and weight and skinfolds were lowest early in the season. LMI appears to be a reasonably valid tool for monitoring lean mass changes.  相似文献   

Record Values and Surviving Glacial Moraines     

Roger Johnson 《Teaching Statistics》2003,25(3):66-69

Estimating the number of glacial advances from surviving glacial debris can, amazingly enough, be cast as a records problem for which there is a substantial statistical literature. As a result, instructors may illustrate method of moments and maximum‐likelihood estimation techniques with an interesting problem in the physical sciences.  相似文献   

Enhancing nursing home care for seniors: impact of a living classroom on nursing assistant’s education     

Veronique M. Boscart  Lynn McCleary  Paul Stolee  Linda Sheiban Taucar  Jessica Wilhelm  Keia Johnson 《Educational gerontology》2020,46(8):461-472

ABSTRACT

Nursing Assistants (NAs) are the largest workforce in nursing homes, but often lack adequate preparation for their role. The Living Classroom (LC) is an integrated learning approach, whereby a NA program is delivered in a nursing home (NH) in collaboration with a community college. This paper describes the implementation and evaluation of the LC. Mixed methods were used to gather data from 48 NA students, 5 faculty, and 42 NH staff over 30 weeks. Students, faculty, and nursing home staff described the LC as a positive learning experience. Students’ gerontological knowledge increased over time (p = .0012). Students reported very positive relationships with program mentors and NH residents. The LC provides a unique approach to prepare NAs to work in nursing homes. This model could expand to other educational programs with a gerontology focus.  相似文献   

STATISTICAL DIVERSIONS     

Peter Petocz  Eric Sowey 《Teaching Statistics》2003,25(3):96-96

  相似文献   

Girls in science — An evaluation of one school's approach to the gender bias in science     

Barbara Johnson  Peter Fensham  Gail Hildebrand  Shirley Sampson 《Research in Science Education》1987,17(1):104-112

Conclusions As the pilot project has only been in operation for one semester there are no profound statements that can be made. What we have at present is the base information for comparison of all data over the duration of the project. Cross tabulation of the data to date has begun. However it should be re-iterated here that there appears to be a lack of understanding by the parents' as to the reason for the all-girls classes at the school and that this situation may be due to the fact that in this school community we have the typical sex-stereotyping roles and attitudes existing. The big question is, Will this intervention strategy of single-sex science classes be effective in altering the girls views about what is appropriate for them to study or follow as a career?  相似文献   

Academic Follow-Up Data on Two Cohorts of High-Risk Transfer Children     

Leonard A. Jason  Karen E. Danner  Andrew M. Weine  Karen S. Kurasaki  Jay H. Johnson  Luann Warren-Sohlberg  Olga Reyes 《Early education and development》1994,5(4):277-288

Two cohorts of children from inner-city elementary schools were provided a tutoring intervention to help in their transition to new schools. Participants were third, fourth, and fifth grade children who were identified as having low-income status, evidencing lags on achievement tests, and experiencing stressful life events. The intervention involved an orientation program with twice weekly paraprofessional tutoring. Two and three year academic and sociometric follow-up data were collected. Those provided the intervention evidenced some improvements over time, and these changes were most prominent in the area of reading grades. Fewer significant findings were found on sociometric indices.  相似文献   

Working with Low Survey Response Rates: The Efficacy of Weighting Adjustments   总被引：1，自引：2，他引：1  

Dey  Eric L. 《Research in higher education》1997,38(2):215-227

National data show a continuing decline in the willingness of people to respond to surveys. This trend is troubling given the central role that survey research plays in collecting data for institutional research purposes. This paper examines the effectiveness of a weighting procedure described by Astin and Molm for adjusting survey results to correct for nonresponse bias. Using data from a Cooperative Institutional Research Program (CIRP) follow-up survey, the results indicate that the weighting procedure is highly effective at reducing nonresponse bias in univariate distributions. The effectiveness of the weighting procedure in adjusting correlation and regression analyses is less clear. This may be due in part to the observation that even when individual variables are noticeably biased, their relationships with each other tend not to be.  相似文献   

Assessing a Holistic Trait and Factor Approach to Career Development of College Students     

Patrick Johnson  Cassandra N. Nichols  Walter C. Buboltz  Brian Riedesel 《Journal of College Counseling》2002,5(1):4-14

To assess the impact of a holistic career and life planning course on college students, the authors asked 209 students in treatment and control groups to complete measures of career development. Results indicate that the course significantly increases vocational identity and career decision‐making self‐efficacy and decreases career indecision.  相似文献   

Improving the Acquisition of Novel Vocabulary Through the Use of Imagery Interventions     

Marisa T. Cohen  Helen L. Johnson 《Early Childhood Education Journal》2011,38(5):357-366

The purpose of this study was to investigate the impact of imagery interventions on the vocabulary acquisition abilities of second grade students. A total of 15 students were randomly assigned to three different intervention conditions: Word Only, which involves the simple verbal presentation of a vocabulary word; Dual Coding, in which a picture was paired with the vocabulary word, and Image Creation, in which students were told to create a mental picture of the vocabulary word in their mind and draw it on paper. These students were taught a total of 21 vocabulary words: seven animal and habitat words, seven musical instrument terms, and seven science terms. A Latin square design was used, in which each group of students rotated through each of the interventions, being exposed to a different treatment condition for each category of words. Participants were measured on the number of words they were successfully able to acquire through the use of experimenter designed comprehension measures. While no statistical significance was shown between the interventions across the word categories, a significant difference was found between the Image Creation and Word Only interventions within the science terms category. Students also reported that the imagery interventions facilitated the ease with which they learned the words. The findings have implications for increasing the success of classroom instruction, specifically for presenting novel vocabulary words to early elementary learners using imagery methods.  相似文献