Effects of residual fatigue on pace regulation during sprint-distance triathlon running

Introduction: It has been suggested that unique relationships exist between perceived exertion, pacing and physiological responses during triathlon. However, research to date has not clearly established how the interaction of these factors is affected by residual physiological fatigue, particularly during running performance over distances relevant to sprint-distance triathlon. This study therefore investigated the effects of the preceding swim and cycle on pacing strategy, perceived exertion, and physiological status during sprint-distance triathlon running. Methods: Eight amateur male triathletes (mean ± SD: age 36.0 ± 5.7 yrs, mass 75.7 ± 5.3 kg) completed two field-based performance trials. The first was a sprint-distance triathlon (0.75 km swim, 20 km cycle, 5 km run) and the second an isolated 5 km run time-trial, each separated by 7-18 days and utilising the same flat out-and-back road course. Wrist-mounted GPS devices (Garmin 310XT, UK) recorded performance time, running speed (km•h-1) and heart rate during each trial. Participants recorded ratings of perceived exertion (Borg 6-20 scale) every kilometre using a wrist-mounted recording sheet and pen. Core temperature (CorTemp, HQInc, USA), blood lactate concentration (Lactate Pro, Kodak, Japan) and body mass (to 0.1 kg; Seca 875) were also measured immediately prior to, and after, each run. Results: Performance time for isolated running (19:28 ± 00:32) was ~7% quicker than triathlon running (20:48 ± 00:43) (p<0.01), with a similar positive pacing strategy displayed throughout both trials (figure 1). Initial core temperature, blood lactate concentration and heart rate values were all significantly higher for the triathlon run compared to the isolated run (p<0.01), with no differences in final values for these measures. No significant differences were observed for initial RPE, rate of RPE increase, or final RPE between runs. Discussion/Conclusion: Prior swimming and cycling impair performance but do not affect pacing strategy during sprint-distance triathlon running. Reduced performance may be attributed to the residual physiological strain observed at the start of the triathlon run. However, the maintenance of scalar-linear increases in RPE appears to be the primary regulator of pacing strategy during triathlon running, with physiological responses only indirectly related to this process

Effect of plyometric training on swimming block start performance in adolescents

This study aimed to identify the effect of plyometric training (PT), when added to habitual training (HT) regimes, on swim start performance. After the completion of a baseline competitive swim start, 22 adolescent swimmers were randomly assigned to either a PT (n = 11, age: 13.1 ± 1.4 yr, mass: 50.6 ± 12.3 kg, stature: 162.9 ± 11.9 cm) or an HT group (n = 11, age: 12.6 ± 1.9 yr, mass: 43.3 ± 11.6 kg, stature: 157.6 ± 11.9 cm). Over an 8-week preseason period, the HT group continued with their normal training program, whereas the PT group added 2 additional 1-hour plyometric-specific sessions, incorporating prescribed exercises relating to the swimming block start (SBS). After completion of the training intervention, post-training swim start performance was reassessed. For both baseline and post-trials, swim performance was recorded using videography (50Hz Canon MVX460) in the sagital plane of motion. Through the use of Silicon Coach Pro analysis package, data revealed significantly greater change between baseline and post-trials for PT when compared with the HT group for swim performance time to 5.5 m (−0.59 s vs. −0.21 s; p < 0.01) and velocity of take-off to contact (0.19 ms−1 vs. −0.07 ms−1; p < 0.01). Considering the practical importance of a successful swim start to overall performance outcome, the current study has found that inclusion of suitable and safely implemented PT to adolescent performers, in addition to HT routines, can have a positive impact on swim start performance

The Correlation Between a Pre-Engineering Student\u27s Spatial Ability and Achievement in an Electronics Fundamentals Course

Though there is ample evidence showing a positive relationship between a student\u27s spatial ability and achievement in many fields of science, technology, and engineering, this study was seeking evidence that a relationship exists between a pre-engineering student\u27s spatial ability and achievement in an electronics fundamentals course. The importance of spatial ability to mentally design, develop, and manipulate images has been linked to measures of practical and mechanical abilities that are quite useful in technical occupations. Spatial abilities are frequently attributed to creative and higher order thinking skills in science and mathematics. Spatial imagery is tremendously important in art and creative thinking, and has an important role in abstract engineering disciplines such as electronics. This study included 154 students enrolled in two sections of a fundamentals electronics course. The average age of the students enrolled in this course was 22.64 years old. The majority (89.6%) of the students was male, and 59.1% of the students majored in mechanical engineering. The average GPA of the participants was 3.4. The participants scored well on the spatial ability test (avg. 17.5, out of a possible 20), and the average grade received in the course was a B (avg. 85.6, out of a possible 100). This study showed a highly significant (.000 alpha 1-tailed level) and near medium (Pearson\u27s r of .29) correlation strength between spatial ability and achievement in the course. There was significant positive correlation between GPA and spatial ability--corroborating that pre-engineering students with high GPAs also have high spatial ability. When controlling for GPA in a partial correlation, it was found that spatial ability accounted for a significant amount of the variance in the semester scores, which suggests that spatial ability provides some good prediction of doing well in an electronics fundamentals course above and beyond what GPA predicts alone. Many STEM subjects are at the atomic level and require using mental models that are created in the mind\u27s eye and necessarily require spatial reasoning ability. The understanding of a given aspect of the physical world is best conceptualized with a mental model

The Relationship between Leadership Style and Volunteer Intention to Stay

Many organizations rely on volunteers to perform key elements of support, and leadership style plays an important role in the retention of volunteers. The purpose of the study was to examine the relationship between leadership style and the intent to stay for adult and youth volunteers in a large nonprofit organization. This quantitative study examined the relationship of leadership style and intention to stay with three samples of volunteers: local leaders (n = 91), adult volunteers (n = 48), and youth volunteers (n = 42). A survey was administered via online survey tool for leaders and adult volunteers, and with hardcopy questionnaires mailed to youth volunteers. Data analysis included descriptive statistics, correlational analyses, and analyses of variance. A statistically significant correlation existed between leadership style and intention to stay for leaders and adult volunteers, while the correlation between the variables for leaders and youth volunteers was not statistically significant. Leaders rated themselves as stronger in servant leadership qualities, while adult volunteers and youth volunteers rated their leaders lower. Gender differences existed in how volunteers rated their leaders. Adult female volunteers rated their leaders at statistically significant lower levels than did their male counterparts, while female youth volunteers rated their leaders at statistically significant higher levels than did their male counterparts. Organizations that rely on volunteers should incorporate servant leadership skills into their training programs and encourage their leaders to embrace the principles of servant leadership

The Relationship Between Leadership Style and Volunteer Intention to StayMark

Cohort X

The Relationship between Leadership Style and Volunteer Intention to Stay

Many organizations rely on volunteers to perform key elements of support, and leadership style plays an important role in the retention of volunteers. The purpose of the study was to examine the relationship between leadership style and the intent to stay for adult and youth volunteers in a large nonprofit organization. This quantitative study examined the relationship of leadership style and intention to stay with three samples of volunteers: local leaders (n = 91), adult volunteers (n = 48), and youth volunteers (n = 42). A survey was administered via online survey tool for leaders and adult volunteers, and with hardcopy questionnaires mailed to youth volunteers. Data analysis included descriptive statistics, correlational analyses, and analyses of variance. A statistically significant correlation existed between leadership style and intention to stay for leaders and adult volunteers, while the correlation between the variables for leaders and youth volunteers was not statistically significant. Leaders rated themselves as stronger in servant leadership qualities, while adult volunteers and youth volunteers rated their leaders lower. Gender differences existed in how volunteers rated their leaders. Adult female volunteers rated their leaders at statistically significant lower levels than did their male counterparts, while female youth volunteers rated their leaders at statistically significant higher levels than did their male counterparts. Organizations that rely on volunteers should incorporate servant leadership skills into their training programs and encourage their leaders to embrace the principles of servant leadership

Economics of Water Quality Protection from Nonpoint Sources: Theory and Practice

Water quality is a major environmental issue. Pollution from nonpoint sources is the single largest remaining source of water quality impairments in the United States. Agriculture is a major source of several nonpoint-source pollutants, including nutrients, sediment, pesticides, and salts. Agricultural nonpoint pollution reduction policies can be designed to induce producers to change their production practices in ways that improve the environmental and related economic consequences of production. The information necessary to design economically efficient pollution control policies is almost always lacking. Instead, policies can be designed to achieve specific environmental or other similarly related goals at least cost, given transaction costs and any other political, legal, or informational constraints that may exist. This report outlines the economic characteristics of five instruments that can be used to reduce agricultural nonpoint source pollution (economic incentives, standards, education, liability, and research) and discusses empirical research related to the use of these instruments.water quality, nonpoint-source pollution, economic incentives, standards, education, liability, research, Environmental Economics and Policy,

Carbon changes in conterminous US forests associated with growth and major disturbances.

Abstract We estimated forest area and carbon changes in the conterminous United States using a remote sensing based land cover change map, forest fire data from the Monitoring Trends in Burn Severity program, and forest growth and harvest data from the USDA Forest Service, Forest Inventory and Analysis Program. Natural and human-associated disturbances reduced the forest ecosystems\u27 carbon sink by 36% from 1992 to 2001, compared to that without disturbances in the 48 states. Among the three identified disturbances, forest-related land cover change contributed 33% of the total effect in reducing the forest carbon potential sink, while harvests and fires accounted for 63% and 4% of the total effect, respectively. The nation\u27s forests sequestered 1.6 ± 0.1Pg (1015 petagram) carbon during the period, or 0.18PgCyr-1, with substantial regional variation. The southern region of the United States was a small net carbon source whereas the greater Pacific Northwest region was a strong net sink. Results of the approach fit reasonably well at an aggregate level with other related estimates of the current forest US greenhouse gas inventory, suggesting that further research using this approach is warranted