Browsing by Subject "Running"

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    Comparison of tibial geometry, density and strength between adult female dancers, gymnasts and runners
    (2014-02) Bellard Freire Ribeiro, Ana Cristina
    Physical activity has a site-specific osteogenic effect that is known to positively improve bone health (Schoenau, 2006, Greene, 2006, Uusi-Rasi, 2006). The effect of dancing on bone health has received sparse attention and the extent of the osteogenic effect of dancing is not known. Given that dancing may be considered a medium impact activity, one would expect that the magnitude of its osteogenic effect might be between those of high impact activities such as gymnastics and cyclic low impact activities like running with the most pronounced effects in the weight bearing bones such as the tibia and femur. Thus, the purpose of this study is to compare the osteogenic effects of dance, gymnastics and middle/long-distance running in adult females, as measured by tibial geometry, density, and strength. Methods: Eleven dance majors and eleven collegiate gymnasts (ages 18-22) were recruited for the study. Runner (n=22) and control (n=19) data were obtained from the UM Laboratory of Musculoskeletal Health database (Smock et al., 2009 and Bruininks, 2009). The control subjects were young adult, sedentary females. Total cross-sectional area (ToA) was measured by peripheral quantitative computed tomography (pQCT) at the tibia (4% and 66% from its distal end); total volumetric bone mineral density (vBMD) and bone strength index (BSI) were measured at the 4% site. Polar strength-strain index (SSIp) was measured at the 66% site. Results: After controlling for height and body mass, the distal and proximal cross-sectional areas of the tibia (ToA 4%, ToA 66%) and SSIp did not differ significantly between groups. However, total vBMD was significantly higher for dancers and gymnasts when compared to controls (p=0.01 and p=0.02, respectively). In addition, BSI was significantly higher for dancers, gymnasts, and runners when compared to controls (p=0.001, p<0.001, and p=0.03, respectively). Participants did not differ in age, weight or tibial length, assuring that the samples were not biased with respect to age and anthropometrics.Conclusion:The current results suggest that dance and gymnastics have the greatest osteogenic effects at the tibia in eumenorrheic adult females, followed by middle-long distance running, when compared to sedentary healthy controls.
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    Plyometric training, running economy, and marathon running
    (2015-03) Lundstrom, Christopher John
    Plyometric training (PLYO) improves running economy (RE) and performance in distance races up to 5-km in competitive runners. Core training (CORE) is widely practiced by distance runners, though there is little evidence for its efficacy in improving performance or preventing injury. The purpose of this study was to compare the effects of a weekly PLYO or CORE training program over a 12-week marathon training period on a population of recreational marathon runners. Sprint, jump, and distance running performance, and training variables were assessed. In addition, different approaches to quantifying RE were examined. Competitive (COMP) and recreational (REC) runners were compared, and RE variables were used to model marathon performance. Sprint performance improved with PLYO training. Jump performance was maintained with PLYO training while it decreased in the CORE group. No differences were found in training variables between PLYO, CORE and a no additional training (CON) group, though limited evidence suggests a potential benefit of PLYO training. Other groups increased from baseline (a run-in period of 8 weeks) to the marathon training period in rate of perceived exertion, soreness, and days missed due to injury, while the PLYO group did not experience these negative changes. In addition, pre-marathon creatine kinase (CK) levels were lower in PLYO than CORE runners, and post-marathon CK levels trended toward lower as well. Assessment of RE factors found that correcting 02 utilization for velocity is important in capturing differences between COMP and REC runners, with COMP runners using less O2 per km. This measure was a significant predictor of marathon performance. Within groups, the use of allometric scaling was important in using RE to model marathon performance. Implementation of PLYO training in a population of recreational marathoners can improve sprint and maintain jump performance, but the benefits do not transfer to distance running performance, including RE. Other benefits to health and training variables may be seen, and may be more important to this population. Running economy is an important predictor of marathon performance. Competitive runners are more economical than REC runners, and more economical runners perform better in the marathon, relative to their shorter distance performances.