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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
371

Identifying a Test to Monitor Weightlifting Performance in Competitive Male and Female Weightlifters

Travis, S. Kyle, Goodin, Jacob R., Beckham, George K., Bazyler, Caleb D. 23 May 2018 (has links)
Monitoring tests are commonly used to assess weightlifter’s preparedness for competition. Although various monitoring tests have been used, it is not clear which test is the strongest indicator of weightlifting performance. Therefore, the purpose of this study was to (1) determine the relationships between vertical jump, isometric mid-thigh pull (IMTP) and weightlifting performance; and (2) compare vertical jumps to IMTP as monitoring tests of weightlifting performance in a large cohort of male and female weightlifters. Methods: Fifty-two competitive weightlifters (31 males, 21 females) participated in squat and countermovement jump testing (SJ, CMJ), and IMTP testing performed on force plates. All laboratory testing data was correlated to a recent competition where the athletes had attempted to peak. Results: Squat jump height (SJH) was the strongest correlate for men and women with the Sinclair Total (r = 0.686, p ≤ 0.01; r = 0.487, p ≤ 0.05, respectively) compared to countermovement jump height (r = 0.642, p ≤ 0.01; r = 0.413, p = 0.063), IMTP peak force allometrically scaled to body mass (r = 0.542, p ≤ 0.01; r = −0.044, p = 0.851) and rate of force development at 200 ms (r = 0.066, p = 0.723; r = 0.086, p = 0.711), respectively. Further, SJH was a stronger correlate of relative weightlifting performance compared to IMTP peak force in females (p = 0.042), but not male weightlifters (p = 0.191). Conclusions: Although CMJ and IMTP are still considered strong indicators of weightlifting performance, SJH appears to be the most indicative measure of weightlifting performance across a wide-range of performance levels. Thus, SJH can be used as a reliable measure to monitor weightlifting performance in male and female weightlifters.
372

Bone Mineral Density and Content of Collegiate Throwers: Influence of Maximum Strength

Whittington, J. M., Shoen, E. J., Labounty, L. L., Gentles, Jeremy A., Kraska, Jenna M., Swisher, Ann Marie, Keller, J. E, Stone, Margaret E., Ramsey, Michael W., Hamdy, Ronald C., Stone, Michael H. 14 February 2008 (has links)
Bone is a plastic tissue, changing in density and size with different levels of stress. Furthermore, it appears that BMD is altered in a site specific manner. However, BMD has not been studied extensively in all types of athletes, particularly well trained strengthpower athletes, such as throwers. The pwpose of this study was to examine the BMD of USA Division I collegiate throwers (shot put, discus, etc.). BMD was compared to normative data and to different athletes. Measures of whole body maximum strength and throwing performance were correlated with BMDs. Potential right/left side and sex differences were examined. Athletes were 4 males, 3 females age 19.9 ± 0.9 years. BMD was measured with a DEXA Maximum isometric strength was measured using a midthigh pull standing on a force plate. Force time-curves were generated during the strength tests. Peale force (PF) and normalized pealc force (PFa) were correlated with BMDs. Comparison indicates throwers have denser bones compared to normative data and compared to other types of athletes. Male throwers tend to have greater total body BMD than female throwers (p < 0.05). Dominant arm showed slightly greater BMD compared to non-dominant (p < 0.05). Furthermore, BMD is related to PF (r = 0.68) and PFa (r = 0.56). Throwers have greater BMD's than non-athletes or most other types of athletes. However, throwers showed only a small indication of sidedness. These observations likely stem from their training program (whole body heavy loading).
373

The Relationship of Peak Isometric Strength to Peak Aerobic Power and 3000 M Performance in Cross-country Runners

Swisher, Ann Marie, Kraska, Jenna M., Ramsey, Michael W., Painter, Keith B., Gooden, C., Layne, Andrew S., Sands, William A., Haff, G. Gregory, McBride, Jeff, Stone, Margaret E., Stone, Michael H. 14 February 2008 (has links)
Certain variables: peak aerobic power (PAP), running economy, and lactate threshold, act as limiting factors for endurance running. However, all of the mechanisms underlying high-level endurance running are not completely clear. Alterations in maximum and explosive strength P27 have been shown to effect positive changes in endurance performance, likely by altering P28 running economy. If strength related factors affect running economy, then this should be evident in the running performance of long-distance runners and perhaps PAP. The purpose of this study was to examine the relationships between peak isometric strength (IPF), explosive strength (rate of force development, RFD), PAP and 3 k performance (3KT) among 5 female and 7 male (n = 12) X-country runners. Force-time curve analysis was conducted for each (2 trials) isometric pull and averaged for analyses. IPF and RFD from 0 - 200 ms were determined from appropriate curves. IPFs were normalized using an allometric (IPFa) scaling equation: absolute force/ (body mass (kg)0.67). ICCs were previously shown to be > 0.9. Relationships were established with Pearson's r; statistical differences with at-Test (p < 0.05). !PF, IPFa and RFD were not different between sexes. PAP was statistically greater in males. Correlations were: PAP vs 3KT (r = -0.92); !PF vs PAP (r = 0.58), 3KT (r = -0.66); IPFa vs PAP (r = 0.45), 3KT (r = 0.45). RFD vs PAP (r = 0.58), 3KT (r = -0.65). Results indicate that strength characteristics correlate moderately to strongly with PAP and 3KT. Data suggests that strong.
374

Relationship of Peak Isometric Strength to Rate of Force Development Among Collegiate Track and Field Athletes

Kraska, Jenna M., Swisher, Ann Marie, Ramsey, Michael W., Nelson, C., Sands, William A., Haff, G. Gregory, Hasegawa, H., McBride, Jeff, Stone, Margaret E., Stone, Michael H. 14 February 2008 (has links)
Explosive strength, a function of rate of force development (RFD), is a primary determinant for the amount of peak force that can be produced in critical sport performance time periods ( e.g. foot contact time). Evidence indicates that maximum strength and RFD are correlated. However, the characteristics of this relationship are not well established among athletes. This study examined the relationship of peak isometric force (IPF) and RFD from a mid-thigh pull, among male and female track and field athletes. Athletes were 12 sprinters (S), 10 jumpers (JP) and 12 cross-country runners (XC). Force-time curve analysis was conducted for each (2 trials) isometric pull and averaged for analyses. IPF and RFD from 0 - 200 ms were determined from appropriate curves. IPFs were normalized using an allometric (IPFa) scaling equation: absolute force/ (body mass (kg)0.67). ICCs were previously shown to be > 0.9. Relationships were established with Pearson's r; statistical differences with a Bonferroni adjusted t-Test. IPF, IPFa and RFD were greater in males than females for S and JP but not for XC. IPF, IPFa and RFD were greater for S and JP compared to XC. Similar relationships of IPF to RFD were noted among groups S(r = 0.85), JP (r = 0.87), XC (r = 0.88). Among males, n = 19, the relationship ofIPF to RFD was r = 0.89 and was somewhat higher compared to females, n = 15, (r = 0.78). Overall (n = 34) relationship between IPF and RFD was r = 0.90. These data indicate a strong relationship between maximum strength and "explosiveness" that is independent.
375

Relationship Between Isometric Force Characteristics and Peak Power Output in Static and Countermovement Jumps at Various Loading Conditions

Kraska, Jenna M., Ramsey, Michael W., Kinser, Ann M., Stone, Margaret E., Haff, G. Gregory, Sands, William A., Stone, Michael H. 01 July 2007 (has links)
Abstract available in the Journal of Strength and Conditioning Research
376

Changes in Relationship Between Static Jump Height, Strength Characteristics, and Body Composition With Training

Ramsey, Michael W., Kavanaugh, Ashley A., Israetel, Michael, Swisher, Anna, Nelson, Cara, Stone, Michael H. 04 June 2011 (has links)
Abstract available in the Medicine & Science in Sports & Exercise
377

The Effects of Ovarian Hormones and Exercise on Gene Markers of Cardiac Dysfunction

Patel, Anisha S 17 July 2015 (has links)
Heart disease is the leading cause of death in women in the United States. Premenopausal women appear to have better cardiac function and lower risk of heart disease compared to male postmenopausal female counterparts. Ovarian hormone loss influences blood pressure homeostasis and causes systemic inflammation, which may result in chronic stress on the heart. Two key physiological changes in cardiac dysfunction are reemergence of the fetal gene pattern and myocardial remodeling. Physical activity has been linked to improved cardiac function. The purpose of this study was to investigate the effects of ovariectomy on early markers of cardiac dysfunction and fibrosis and to determine if voluntary physical activity alters expression patterns in ovariectomized mice. We investigated the effects of ovariectomy and exercise on cardiac expression of fetal genes and markers and mediators of fibrosis in two cohorts of 8-10 week old female mice. Ovariectomized mice had greater expression of cardiac fetal genes and real time-PCR (RT-PCR) results indicated activation of the fibrosis pathway. Exercise was able to influence the expression of some markers of cardiac dysfunction. We concluded that ovarian hormone loss and associated physiological changes such as increased adiposity and systemic inflammation trigger early changes in cardiac gene expression that precede overt cardiac dysfunction.
378

The effects of two weight training modes on selected flexibility measures in college age students

Westlake, Steven James 01 January 1990 (has links)
The purpose of this study was to investigate the effects of different strength training modes on joint range of motion. The problem of the study was to compare Nautilus to free-weight training modes in terms of selected joints' ranges of motion before and after an eight-week strength training program. The hypothesis asserted was that there was no difference between pre-test and post-test scores when comparing Nautilus to free-weight training modes. Subjects were thirty college-age students enrolled in beginning weight-training classes at the University of the Pacific. The subjects were acquired from intact classes and comprised two groups of 9 males and 6 females each. Pre-test and post-test flexibility measures were acquired by use of a Leighton Flex-o-meter and sit-and-reach protocols. Single joint measures of shoulder flexion, extension and abduction, hip flexion, extension and abduction, elbow flexion, knee flexion, and low back flexion were acquired. For eight weeks, two times per week, each class completed an 8 to 12 repetitions per each exercise protocol following the principles of training asserted by Nautilus. Pre-test data for all bilateral joints were statistically analyzed with paired t-tests in order to determine any differences. No significant bilateral differences were found; consequently, these data were converted to eight single measures of average range of motion of the joints respectively. Pretest data then were analyzed with two-factor ANOV A (group x gender) in order to determine if the two intact classes initially represented the same population. The only measure in which a group difference was found was shoulder extension (p
379

Bilateral Muscle Oxygenation Kinetics In Response To Repeat Sprint Cycling In Strong And Weak Individuals

Abbott, John 01 May 2020 (has links)
Repeat sprint ability has been investigated thoroughly, however optimal training methodology to improve RSA remains elusive. Both kinetic and physiological viewpoints have been used to scrutinize aspects of RSA including, initial sprint performance (anaerobic power), maximal cardiorespiratory fitness (VO2max), lactate threshold, anaerobic capacity (mean power), muscle activation (EMG), and local muscle oxygenation kinetics. To our knowledge no study has utilized maximal strength levels as a separate factor among a homogenous group of cardiorespiratory fitness individuals (as determined by peak VO2 during RSA). The purpose of this study was to better understand the relationship between maximal strength, muscular characteristics, and cycling RSA- respective to muscle oxygenation responses. Fifteen participants completed fifteen 10-second maximal effort sprints on a cycle ergometer interspersed with 30-seconds passive recovery. Respiratory, muscle oxygenation, and kinetic responses were monitored continuously and evaluated relationships with maximal strength and muscular architecture as determined by isometric mid-thigh pull and ultrasonography respectively. A series of 2 x 15 mixed design, group x time, ANOVA’s were used to evaluate the effects of group and or sprint on muscle oxygenation kinetics. Strong individuals were found to have significantly greater levels of muscle oxygenation usage, recovery and the respective rates; p = 0.01, p = 0.02, p
380

Maximum Strength, Rate of Force Development, Jump Height, and Peak Power Alterations in Weightlifters across Five Months of Training

Hornsby, W. Guy, Gentles, Jeremy A., MacDonald, Christopher J., Mizuguchi, Satoshi, Ramsey, Michael W., Stone, Michael H. 13 October 2017 (has links)
The purpose of this monitoring study was to investigate how alterations in training affect changes in force-related characteristics and weightlifting performance. Subjects: Seven competitive weightlifters participated in the study. Methods: The weightlifters performed a block style periodized plan across 20 weeks. Force plate data from the isometric mid-thigh pull and static jumps with 0 kg, 11 kg, and 20 kg were collected near the end of each training block (weeks 1, 6, 10, 13, 17, and 20). Weightlifting performance was measured at weeks 0, 7, 11, and 20. Results: Very strong correlations were noted between weightlifting performances and isometric rate of force development (RFD), isometric peak force (PF), peak power (PP), and jump height (JH). Men responded in a more predictable manner than the women. During periods of higher training volume, RFD was depressed to a greater extent than PF. JH at 20 kg responded in a manner reflecting the expected fatigue response more so than JH at 0 kg and 11 kg. Conclusions: PF appears to have been more resistant to volume alterations than RFD and JH at 20 kg. RFD and JH at 20 kg appear to be superior monitoring metrics due to their “sensitivity.”

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