Playing at Sevens: The Impulse Load and Movement Demands of Men’s Collegiate Rugby

Rugby sevens is a widely practiced sport that combines high-speed anaerobic activity with positional specific play and many body impacts. Despite its popularity and its intense physical demands on the body, many of these demands have not been fully explored. An investigation into the specifics of these physical demands can aid coaches and athletes in training and preparation for future matches. The purpose of this study was to quantify the Impulse Load and movement dynamics placed on American rugby players during competition. With this data, position specific information was compared to determine differences in physical demands. Fourteen male collegiate rugby sevens players were assigned a microsenor device and bioharness prior to testing. Time motion analysis data was collected using these microsenor devices. Acceleration data was used to calculate Impulse Load and GPS data was used to quantify total distance and distance in six speed zones. The devices were placed on each player, securely fastened around the chest, and worn for the duration of the warm-up and two competitive matches, for a period of 1 hour and 47 minutes. Players were monitored using 5Hz global positioning systems (GPS) and 100Hz triaxial accelerometers. Players were further analyzed and divided by playing position (forwards and backs). The contrasts in physical demands based on position can provide feedback to coaches on position-specific training.Faculty Advisor: Brandi Eveland-Sayer

Original paper Cell free DNA as a marker of training status in weightlifters

The purpose of this investigation was to elucidate the changes in cf-DNA as it relates to fluctuations in resistance training workloads and intensities. The relationship between cell free DNA (cf-DNA), C-reactive protein (CRP), creatine kinase (CK), testosterone (T), cortisol (C), testosterone-cortisol ratio (T:C), body mass and body composition were also examined. Eight weightlifters (5 males and 3 females, age = 25 ± 3.5 yr, body mass = 88.3 ± 22.7 kg, height = 173.8 ±8.4 cm) volunteered to participate in this study. Venous blood samples, body mass and body composition were taken six times, each corresponding to the end of a training phase. CK (p = 0.018, η² = 0.409) and CK %Δ (p \u3c 0.001, η² = 0.594) were the only biochemical variables to reach statistical significance at any point. A number of statistically significant correlations were found among variables. VLD4wk was related to CK %Δ (r = 0.86), VLD4wk %Δ was related CK %Δ (r = 0.86) and TID1wk was related to CRP (r = 0.83). cf-DNA %Δ was correlated with CRP and CRP %Δ (r = 0.83 and 0.86, respectively). CRP and CRP %Δ were correlated with BF % (r = 0.94 and 0.92, respectively). CK and CK %Δ were both related to T:C (r = 0.94 and 0.89, respectively) and T:C %Δ (r = 0.87 and 0.86, respectively). The correlation between cf-DNA and CRP suggests that cf-DNA may be a valuable indicator of inflammation in weightlifters

Cell Free Dna As A Marker Of Training Status In Weightlifters

The purpose of this investigation was to elucidate the changes in cf-DNA as it relates to fluctuations in resistance training workloads and intensities. The relationship between cell free DNA (cf-DNA), C-reactive protein (CRP), creatine kinase (CK), testosterone (T), cortisol (C), testosterone-cortisol ratio (T:C), body mass and body composition were also examined. Eight weightlifters (5 males and 3 females, age = 25 ± 3.5 yr, body mass = 88.3 ± 22.7 kg, height = 173.8 ±8.4 cm) volunteered to participate in this study. Venous blood samples, body mass and body composition were taken six times, each corresponding to the end of a training phase. CK (p = 0.018, η² = 0.409) and CK %Δ (p \u3c 0.001, η² = 0.594) were the only biochemical variables to reach statistical significance at any point. A number of statistically significant correlations were found among variables. VLD4wk was related to CK %Δ (r = 0.86), VLD4wk %Δ was related CK %Δ (r = 0.86) and TID1wk was related to CRP (r = 0.83). cf-DNA %Δ was correlated with CRP and CRP %Δ (r = 0.83 and 0.86, respectively). CRP and CRP %Δ were correlated with BF % (r = 0.94 and 0.92, respectively). CK and CK %Δ were both related to T:C (r = 0.94 and 0.89, respectively) and T:C %Δ (r = 0.87 and 0.86, respectively). The correlation between cf-DNA and CRP suggests that cf-DNA may be a valuable indicator of inflammation in weightlifters

Natural and human-induced prehistoric and historical soil erosion and landscape development in Southwestern Tennessee, USA

Eastern North America has seen widespread soil erosion in recent centuries. While the impact of soil erosion and feedbacks to the environment have been recognized for the period of European settlement, the period of prehistoric cultivation by Native Americans and its effect on soil erosion are largely unexplored. At the Dogwood gully system, a 820,000 m2 watershed located along the Chickasaw Bluff in southwestern Tennessee, extensive geoarchaeological investigations, which include historical data, have enabled a detailed examination of soil erosion history. The results yield insight into the relative influence on soil erosion of human activities (both prehistoric and historical) versus natural geomorphodynamic processes controlled by climate and neotectonics. Three relatively short phases of geomorphic activity occurred throughout the Holocene. In the mid-Holocene climate changes caused a change or decline in the protecting vegetation cover which triggered fires, runoff, and soil erosion. The influence of Archaic and early Woodland peoples on the landscape has remained elusive. The loss of at least 12 cm of topsoil during the Mississippi period (∼900-1400 CE) may have influenced land abandonment in the 14th century. After the introduction of European agricultural techniques, a similar amount of soil was eroded but within a period of only 80 years. In the 1930s the area was reforested but runoff and gullying are still active on bare surfaces. The research shows that the impact of prehistoric land use patterns on the geomorphic system was likely generally much more important than previous studies has suggested

PERCEIVED PHYSICAL ABILITY AND SELF-PERCEPTION OF ADEQUACY AND ENJOYMENT FOR PHYSICAL ACTIVITY IN ELEMENTARY STUDENTS

How children perceive their physical ability is important in understanding their reported adequacy, preferences, and predilection of physical activity. This relationship is useful in identifying lifelong physical activity behaviors. Purpose: To examine the relationship between perceived physical ability and self-perceptions of adequacy and enjoyment of physical activity in elementary school children. Methods: Students (N = 120) in grades K-5 completed the Perceived Physical Ability Scale (PPAS) and the Children’s Self-Perceptions of Adequacy and Predilection for Physical Activity (CSAPPA). Results: A statistically strong significant positive correlation (r = .49, P \u3c .01) was found between the PPAS and CSAPPA indicating that students with higher perceived physical ability also reported higher scores on the CSAPPA. The high CSAPPA scores are indicative of students having a higher likelihood of choosing physical activity over a non-active option. No significant differences were noted between males and females or across grade levels. Conclusions: Based on these results students who have a greater perception of their physical ability also report being more likely to select a physically active option when given the choice. The findings of this study are noteworthy as previous studies have shown that differences between male and female students may exist with similar measures. These results may be indicative of the environment that has been created at the study site. The study site promotes a culture centered on respect, care, and a growth mindset within its student body. Future research comparing student to teacher ratio, cohesive student groups, and school schedules should be conducted to compare students’ PPAS and CSAPPA results. Programs designed to enhance perceived physical ability and enjoyment of physical activity are needed to promote lifetime physical activity habits

ATTITUDES TOWARDS PHYSICAL ACTIVITY PARTICIPATION AND SCHOOL ENGAGEMENT IN ELEMENTARY SCHOOL CHILDREN

Numerous benefits are associated with physical activity participation with recent evidence indicating this may transfer into the classroom environment. Purpose: The purpose of this study was to investigate the relationship between attitudes towards active or passive physical activity participation and classroom engagement in elementary school children. Methods: Students (n = 67) in grades 3-5 completed The Children’s Self-Perceptions of Adequacy in and Predilection for Physical Activity (CSAPPA) and The Elementary Student Engagement Instrument (SEI). Results: A statistically significant positive correlation (r = .31, P \u3c .05) was found between the CSAPPA and SEI indicating that students who prefer active participation in physical activity also report higher levels of engagement within the school environment. No statistical difference was noted between males and females or across grade levels. Conclusion: The results of this research support the benefits of physical activity participation within the school environment. The lack of statistical difference with regard to sex is also noteworthy in that research connecting physical activity and classroom engagement frequently indicates differences between males and females. This is possibly attributed to the inclusive culture established by the school which promotes and supports opportunities for all students. These findings are particularly relevant in light of current trends to reduce time spent in physical education, free play, and other physical activity opportunities within the school day

Cell free DNA as a marker of training status in weightlifters

The purpose of this investigation was to elucidate the changes in cf-DNA as it relates to fluctuations in resistance training workloads and intensities. The relationship between cell free DNA (cf-DNA), C-reactive protein (CRP), creatine kinase (CK), testosterone (T), cortisol (C), testosterone-cortisol ratio (T:C), body mass and body composition were also examined. Eight weightlifters (5 males and 3 females, age = 25 ± 3.5 yr, body mass = 88.3 ± 22.7 kg, height = 173.8 ±8.4 cm) volunteered to participate in this study. Venous blood samples, body mass and body composition were taken six times, each corresponding to the end of a training phase. CK (p = 0.018, η² = 0.409) and CK %Δ (p < 0.001, η² = 0.594) were the only biochemical variables to reach statistical significance at any point. A number of statistically significant correlations were found among variables. VLD4wk was related to CK %Δ (r = 0.86), VLD4wk %Δ was related CK %Δ (r = 0.86) and TID1wk was related to CRP (r = 0.83). cf-DNA %Δ was correlated with CRP and CRP %Δ (r = 0.83 and 0.86, respectively). CRP and CRP %Δ were correlated with BF % (r = 0.94 and 0.92, respectively). CK and CK %Δ were both related to T:C (r = 0.94 and 0.89, respectively) and T:C %Δ (r = 0.87 and 0.86, respectively). The correlation between cf-DNA and CRP suggests that cf-DNA may be a valuable indicator of inflammation in weightlifters

Hormone and Adipokine Alterations across 11 Weeks of Training in Division 1 Collegiate Throwers: An Exploratory Study

Introduction: Conceptually, it is important to understand the underlying physiological mechanisms of any training program model. This understanding aids the coach/sport scientist in making better choices in manipulating variables in formulating the training model. These underlying mechanisms can be associated with training variable manipulation, fatigue management aspects and the overall health of the athlete. Hormone and cytokine concentrations can be linked to alterations resulting from the manipulation of training variables and to subsequent alterations in performance. For example, alterations in the testosterone: cortisol ratio (T:C) has been associated with alterations in training volume as well as physiological aspects such as lean body mass, fat content and strength/power performance. Although cytokine production is part of the adaptive process, markedly increased/excessive cytokine production has been related poor fatigue management and over training. Purpose: The purpose of this study was to investigate the alterations and relationships among training variables, and physiological variables. Subjects: Nine (9) D-1 collegiate throwers and 4 control subjects participated in the study. Methods: The throwers participated in an 11- week periodized resistance training and throws program. Volume load was recorded throughout the study. Hormone (testosterone and cortisol (C), and adipokine (adiponectin, leptin, and resistin) measurements were taken at weeks 1, 7, and 11 for the throwers. Results: Hormone values did not exhibit statistically significant changes across time; however, there were trends across time for C, the T:C ratio and adiponectin. Conclusions: Based on the hormonal and adipokine data, it appears that the training program produced some positive effects. These effects indicate a reasonable degree of fatigue management in that C decreased and the T:C ratio was increased as volume load decreased. Literature supports the idea that increases in adiponectin may be a positive outcome of a sound training protocol (Smith et al., 2000). The present observation indicates that adiponectin increased in concert with decreases in C and increases in the T:C. ratio. Considering the effects of these hormones and cytokines, these alterations over time indicate a lesser degree of obesity related inflammation and a higher degree of “fitness” and preparednes

The Relationship between Accelerometry, Global Navigation Satellite System, and Known Distance: A Correlational Design Study

: Previous research has explored associations between accelerometry and Global Navigation Satellite System (GNSS) derived loads. However, to our knowledge, no study has investigated the relationship between these measures and a known distance. Thus, the current study aimed to assess and compare the ability of four accelerometry based metrics and GNSS to predict known distance completed using different movement constraints. A correlational design study was used to evaluate the association between the dependent and independent variables. A total of 30 physically active college students participated. Participants were asked to walk two different known distances (DIST) around a 2 m diameter circle (small circle) and a different distance around an 8 m diameter circle (large circle). Each distance completed around the small circle by one participant was completed around the large circle by a different participant. The same 30 distances were completed around each circle and ranged from 12.57 to 376.99 m. Acceleration data was collected via a tri-axial accelerometer sampling at 100 Hz. Accelerometry derived measures included the sum of the absolute values of acceleration (SUM), the square root of the sum of squared accelerations (MAG), Player Load (PL), and Impulse Load (IL). Distance (GNSSD) was measured from positional data collected using a triple GNSS unit sampling at 10 Hz. Separate simple linear regression models were created to assess the ability of each independent variable to predict DIST. The results indicate that all regression models performed well (R = 0.960-0.999, R = 0.922-0.999; RMSE = 0.047-0.242, \u3c 0.001), while GNSSD (small circle, R = 0.999, R = 0.997, RMSE = 0.047 \u3c 0.001; large circle, R = 0.999, R = 0.999, RMSE = 0.027, \u3c 0.001) and the accelerometry derived metric MAG (small circle, R = 0.992, R = 0.983, RMSE = 0.112, \u3c 0.001; large circle, R = 0.997, R = 0.995, RMSE = 0.064, \u3c 0.001) performed best among all models. This research illustrates that both GNSS and accelerometry may be used to indicate total distance completed while walking