Beating Yourself: How Do Runners Improve Their Own Records?

2020 ◽  
Vol 15 (3) ◽  
pp. 437-440 ◽  
Author(s):  
Carl Foster ◽  
Jos J. de Koning ◽  
Christian Thiel ◽  
Bram Versteeg ◽  
Daniel A. Boullosa ◽  
...  

Background: Pacing studies suggest the distribution of effort for optimizing performance. Cross-sectional studies of 1-mile world records (WRs) suggest that WR progression includes a smaller coefficient of variation of velocity. Purpose: This study evaluates whether intraindividual pacing used by elite runners to break their own WR (1 mile, 5 km, and 10 km) is related to the evolution of pacing strategy. We provide supportive data from analysis in subelite runners. Methods: Men’s WR performances (with 400-m or 1-km splits) in 1 mile, 5 km, and 10 km were retrieved from the IAAF database (from 1924 to present). Data were analyzed relative to pacing pattern when a runner improved their own WR. Similar analyses are presented for 10-km performance in subelite runners before and after intensified training. Results: WR performance was improved in 1 mile (mean [SD]: 3:59.4 [11.2] to 3:57.2 [8.6]), 5 km (13:27 [0:33] to 13:21 [0:33]), and 10 km (28:35 [1:27] to 28:21 [1:21]). The average coefficient of variation did not change in the 1 mile (3.4% [1.8%] to 3.6% [1.6%]), 5 km (2.4% [0.9%] to 2.2% [0.8%]), or 10 km (1.4% [0.1%] to 1.5% [0.6%]) with improved WR. When velocity was normalized to the percentage mean velocity for each race, the pacing pattern was almost identical. Very similar patterns were observed in subelite runners in the 10 km. When time improved from 49:20 (5:30) to 45:56 (4:58), normalized velocity was similar, terminal RPE increased (8.4 [1.6] to 9.1 [0.8]), coefficient of variation was unchanged (4.4% [1.1%] to 4.8% [2.1%]), and VO2max increased (49.8 [7.4] to 55.3 [8.8] mL·min−1·kg−1). Conclusion: The results suggest that when runners break their own best performances, they employ the same pacing pattern, which is different from when WRs are improved in cross-sectional data.

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Caroline Y. Doyon ◽  
Martin Brochu ◽  
Virginie Messier ◽  
Marie-Ève Lavoie ◽  
May Faraj ◽  
...  

Introduction. Subcutaneous fat (ScF) and visceral fat (VF) measurements using CT scan are expensive and may imply significant radiation doses. Cross-sectional studies using CT scan showed that ScF and VF are significantly correlated with abdominal fat measured by DXA (AF-DXA). The association has not been studied after a weight loss.Objective. To determine (1) the associations between AF-DXA and ScF and VF before and after weight loss and (2) the associations between their changes.Methods. 137 overweight/obese postmenopausal women were divided in two groups (1-caloric restriction or 2-caloric restriction + resistance training). AF was assessed using DXA and CT scan.Results. Correlations between AF-DXA and ScF (before:r=0.87, after;r=0.87;P<.01) and, AF-DXA and VF (before:r=0.61, after;r=0.69;P<.01) are not different before and after the weight loss. Correlations between delta AF-DXA and delta ScF (r=0.72;P<.01) or delta VF (r=0.51;P<.01) were found.Conclusion. The use of AF-DXA as a surrogate for VF after weight loss is questionable, but may be interesting for ScF.


Author(s):  
Raghavan Srinivasan ◽  
Daniel Carter ◽  
Craig Lyon ◽  
Matthew Albee

This study determined the crash modification factors (CMFs) associated with horizontal curve realignment using the before–after empirical Bayes method and compared the results from published CMFs from cross-sectional studies. This evaluation used data from rural, two-lane roads in California, North Carolina, and Ohio. The evaluation revealed a 68% reduction in total crashes, a 74% reduction in injury and fatal crashes, a 78% reduction in run-off-road and fixed object crashes, a 42% reduction in crashes during dark conditions, and an 80% reduction in wet-road crashes, all of which were statistically significant at the 95% confidence level. The results pertain to a range of site characteristics, the most important of which is the range of before and after degree of curve. The average degrees of curve in the before and after periods were 18.1 (with a minimum of 3.2 and a maximum of 52.1) and 6.9 (with a minimum of 0.0 and a maximum of 16.3), respectively. The average central angle of the curves was approximately 42° (with a minimum of 1 and a maximum of 117). The CMFs from this before–after evaluation are lower compared to CMFs estimated from two previous cross-sectional studies. There is a need for further research with a larger sample of sites to assess the reliability of the CMFs obtained from this before–after evaluation.


2013 ◽  
Vol 31 (12) ◽  
pp. 1583-1591 ◽  
Author(s):  
Michael Coory ◽  
Victoria M. White ◽  
Kristin S. Johnson ◽  
David J. Hill ◽  
Michael Jefford ◽  
...  

Purpose Summary evidence on the effectiveness of quality improvement interventions (QIIs) directed at cancer specialists is needed for two reasons. First, there are some innovations over which only cancer specialists have control (eg, surgical technique or chemotherapy regimen). Second, implementation of QIIs has opportunity costs; the time and money spent on an ineffective QII might be better spent on direct patient care. Methods Medical Subject Headings and text words for “quality improvement” were combined with those for “neoplasm” to search MEDLINE, PsycINFO, CINAHL, and EMBASE from January 1990 to August 2012 for studies of QIIs directed at cancer specialists (eg, medical/radiation oncologist, surgeon). All study designs were included. Results Five thousand seven hundred eighty-one articles were screened, but only 12 met the inclusion criteria, including three cluster randomized controlled trials (cRCTs), seven uncontrolled before-and-after comparisons, and two cross-sectional studies. All 12 studies were conducted in response to concerns about quality of care. No cRCT showed a benefit of the QIIs tested. Some uncontrolled before-and-after and cross-sectional studies reported a benefit from the QII, but these studies are difficult to interpret because of concerns about uncontrolled confounding. Interventions in all studies were multifaceted, but descriptions of different components were limited, and only one study examined their separate impact. Conclusion The published evidence about how to facilitate timely and consistent adoption of new clinical knowledge by cancer specialists into everyday clinical practice is thin. More investment is needed in research about the solution (QIIs) to match the investment in research about the problem (inconsistent/slow adoption of innovative cancer treatments).


Author(s):  
Bo Lan ◽  
Raghavan Srinivasan

Cross-sectional and the empirical Bayes (EB) before–after are two of the most common methods for estimating crash modification factors (CMFs). The EB before–after method has now been accepted as one way of addressing the potential bias caused by the regression to the mean problem. However, sometimes before–after methods may not feasible because of the lack of data from before and after periods. In those cases, researchers rely on cross-sectional studies to develop CMFs. However, cross-sectional studies may provide biased CMFs through confounding. The propensity score (PS) matching method, along with cross-sectional regression models, is one of the methods that can be used to address confounding. Though PS methods are widely used in epidemiology and other studies, there are only a few studies that have used PS matching methods to estimate CMFs. The intent of this study is to evaluate and compare the performance of cross-sectional regression models using PS matching methods with the results from the EB and traditional cross-sectional methods. The comparisons were conducted using two carefully selected simulated datasets. The results indicate that optimal propensity score distance (PSD) matching with maximum variable ratio of 5 performed quite well compared with the EB before–after and the traditional cross-sectional methods.


Author(s):  
Sanjeeva Kumar Goud T ◽  
Rahul Kunkulol

The present study was aimed to study the effect of Sublingual Vitamin D3 on Serum Vitamin D level in Vitamin D deficiency patients. This was a cross-sectional and interventional study. All the Vitamin D deficiency patients of age 18-60years and either gender, willing to participate in the study were included. Patients who had greater than 20 ng/ml were excluded from the study. The total number of participants in our study was 200, out of these 111 males and 89 females, the mean age in our study was 51.07 ± 7.39Yrs. All volunteers were given sublingual vitamin D3 (60,000IU) in six doses every fifteen days of follow up for 3 months. The subject’s serum 25(OH)D levels were estimated before and after the treatment of sublingual vitamin D3. There was a statistically significant difference in serum vitamin D3 level before 16.61±6.71 ng/ml and after 35.80±7.80 ng/ml after treatment with Sublingual Vitamin D3. Six doses of 60,000IU of Vitamin D3 sublingual route having improved the role of serum 25(OH)D levels in the treatment of Vitamin D3 deficiency patients.Keywords: Vitamin D3; Sublingual route


Author(s):  
I Ketut Widana

The working practice of the engineering students is part of the learning process that is irreducible and indispensable. The composition of  lecturing between theoretical and practical one is 40% to 60%. With this condition, the students spend more time at the laboratory. Generally, the students perform in the laboratory work by standing position. The design of research is observational cross-sectional. The method applied is observation, interview and measuring. The subjects of research are practicing students amounting to 21 students. Referring to the analysis of statistical test or Wilcoxon signed ranks test, the difference of effect of work position is significant, namely p < 0.05 towards musculoskeletal disorders (MSDs) before and after working. The quantity of the average complaint after working is score 44.62 ± 9.47. The result of Wilcoxon signed rank test shows that there is significant different effects of standing work position, namely p < 0.05 towards fatigue generally before and after working. The degree of the working pulse is on the average of 110.78  ± 17.80 bpm (beats per minutes) which can be categorized into the medium workload. Using paired t-test, the result is p < 0.05.


Healthcare ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 747
Author(s):  
Sahbanathul Missiriya Jalal ◽  
Fahima Akhter ◽  
Amal Ismael Abdelhafez ◽  
Ahmed Mansour Alrajeh

Biomedical waste (BMW) management is an essential practice of healthcare professionals (HCPs) for preventing health and also environmental hazards. Coronavirus disease (COVID-19) has become a global pandemic, posing significant challenges for healthcare sectors. A cross-sectional study was performed to assess the knowledge, practice, and attitude on BMW management among HCPs when taking care of patients with COVID-19 and associated with demographic variables. From Al-Ahsa healthcare sectors, 256 HCPs were selected randomly, of which 105 (41%) had excellent knowledge, 87 (34%) had good knowledge, and 64 (25%) had poor knowledge with a mean score of 13.1 ± 3.6. A higher mean score was (14.4 ± 3.2) obtained by physicians, and (13.6 ± 3.8) nurses than the other HCPs. Regarding practice, 72 (28.1%) HCPs used and discarded PPE while handling biomedical wastes. Additionally, 88 (34.4%) followed proper hand hygiene before and after each procedure and whenever needed. Physicians, nurses, and respiratory therapists had a more favorable attitude than other HCPs. There was a statistically significant association found among knowledge level and educational qualification (p < 0.0001), gender (p < 0.001), and work experience (p < 0.05). Emphasis is needed to train all HCPs regarding proper BMW management during this pandemic to prevent infection transmission.


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