Search results for "RUN"
showing 10 items of 2820 documents
Variability and Symmetry of Force Platform Variables in Maximum-Speed Running in Young and Older Athletes
2010
Eighteen young (23 ± 4 yr) and 25 older (70 ± 4 yr) male sprinters were examined for ground reaction force (GRF) and temporal-spatial variables. The data were collected during maximum-speed phase, and variability and symmetry indices were calculated from a total of 8 steps. There was little variation (CV < 6%) in vertical and resultant GRF and kinematic variables, while impact loading had high variability (CV: 10–21%). Overall, the pattern of variability was similar in both groups. Yet, a small but significant age-related increase in CV was evident in horizontal GRFs. There was a variable-specific asymmetry between legs but it was not related to leg dominance. No age differences existed …
Shifts in Key Time Points and Strategies for a Multisegment Motor Task in Healthy Aging Subjects
2018
International audience; In this study, we compared key temporal points in the whole body pointing movement of healthy aging and young subjects. During this movement, subject leans forward from a standing position to reach a target. As it involves forward inclination of the trunk, the movement creates a risk for falling. We examined two strategic time points during the task-first, the crossover point where the velocity of the center of mass (CoM) in the vertical dimension outstripped the velocity in the anteroposterior dimension and secondly, the time to peak of the CoM velocity profile. Transitions to stabilizing postures occur at these time points. They both occurred earlier in aging subje…
Physical Activity and the Changes in Maximal Isometric Strength in Men and Women from the Age of 75 to 80 Years
1997
OBJECTIVE: To research the natural changes in maximal isometric strength, over a period of 5 years, in men and women aged 75 at baseline, and to study the effect of everyday physical activity on strength alterations. DESIGN: A 5-year longitudinal study. SETTING: Exercise laboratory PARTICIPANTS: The target group in 1989 was the total 75-year-old population of Jyvaskyla. One hundred one men (81%) and 186 women (75%) participated in baseline strength tests, and after 5 years, 55 men and 111 women (70% and 72% of the survivors) took part in the follow-up measurements. METHODS: Maximal isometric hand grip, arm flexion, knee extension, trunk flexion, and trunk extension forces were measured usin…
Crossing the Golden Training Divide: The Science and Practice of Training World‑Class 800‑ and 1500‑m Runners
2021
AbstractDespite an increasing amount of research devoted to middle-distance training (herein the 800 and 1500 m events), information regarding the training methodologies of world-class runners is limited. Therefore, the objective of this review was to integrate scientific and best practice literature and outline a novel framework for understanding the training and development of elite middle-distance performance. Herein, we describe how well-known training principles and fundamental training characteristics are applied by world-leading middle-distance coaches and athletes to meet the physiological and neuromuscular demands of 800 and 1500 m. Large diversities in physiological profiles and t…
Segmental contribution to forces in vertical jump.
1978
Performance of a vertical jump was analyzed with respect to the contribution of the different body segments to the forces acting on the whole body center of gravity. Both cinematograph and force-platform techniques were employed. The data disclosed that the take-off velocity in vertical jumps was caused by the different components as follows: knee extension 56%, plantar flexion 22%, trunk extension 10%, arm swing 10%, and head swing 2%. However, the average take-off velocity of the total performance (3.03 m/s) was only 76% from the theoretical maximum calculated from the segmental analyses. Optimal timing of the segmental performances was calculated to increase this “efficiency” to 84%. Gre…
Influence of operative strategy for the aortic arch in DeBakey type I aortic dissection: Analysis of the German Registry for Acute Aortic Dissection …
2012
Objective Patients treated with an extensive approach including total aortic arch replacement for acute aortic dissection type A may have a favorable long-term prognosis by treating the residual false lumen. Our goal was to analyze the operative strategy for treatment of type I DeBakey aortic dissection from the German Registry for Acute Aortic Dissection Type A (GERAADA) data. Methods A total of 658 patients with type I DeBakey aortic dissection and entry only in the ascending aorta were identified in the GERAADA. Patients in group A underwent replacement of the ascending aorta with hemiarch replacement. Patients in group B received extensive treatment with total arch replacement or conven…
Strength and Power Testing of Athletes: A Multicenter Study of Test-Retest Reliability.
2022
Author's accepted manuscript Accepted author manuscript version reprinted, by permission, from International Journal of Sports Physiology and Performance (IJSPP), 2022, 17 (7): 1103-1110, https://doi.org/10.1123/ijspp.2021-0558. © Human Kinetics, Inc. Purpose:This study examined the test–retest reliability of common assessments for measuring strength and power of the lowerbody in high-performing athletes.Methods:A total of 100 participants, including both male (n=83) and female (n=17) athletes(21 [4] y, 182 [9] cm, and 78 [12] kg), were recruited for this study, using a multicenter approach. The participants underwentphysical testing 4 times. Thefirst 2 sessions (1 and 2) were separated by∼…
Mean power during 20 sec all-out test to predict 2000-m rowing ergometer performance in national level young rowers
2014
Aim. The aim of this study was to assess the relationship between mean power during 20-s all-out rowing ergometer test and 2000-m rowing ergometer performance, in 20 young male rowers (mean age 15.2 ± 1.3 years). Methods. Mean power during 20-s all-out test (W20), maximal oxygen uptake during incremental test (VO2max), and anthropometric values, were measured and correlated with the time to perform a 2000-m trial (t2000). Results. W20 showed the highest correlation with t2000 (r = -0.947, P < 0.0001). Stepwise multiple linear regression analysis showed that W20, VO2max, and fat-free mass, were the variables most correlated with t2000, accounting for 95.1% of the variance, and that 89.7% …
Significant correlations between certain spectra of atmospherics and daily periodic activities of Mongolian gerbils (Meriones unguiculatus L.).
1995
We describe significant correlations between 10 and 28 kHz atmospherics (according to Baumer) and the running activities of ten Mongolian gerbils (Meriones unguiculatus L.) depending on their circadian rhythm over a 42-day period (August/September 1988).
Influence of competition on performance factors in under-19 soccer players at national league level.
2020
The aim of this study was to analyse and quantify the acute effects of competition on several performance factors in under-19 male soccer players. To this end, 198 national league players (17.56 ± 0.78 years) performed various tests to measure jump capacity, kicking velocity and sprint times immediately pre-match (T1), at half-time (T2) and post-match (T3). Tests included kicking the ball to measure ball velocity (KICK), sprinting for 40 meters, timing the first 30 meters (30mACCEL), the last 10 meters (10mACCEL) and the total distance (40mACCEL), and performing countermovement jumps (CMJ). For subsequent analysis, the sample was divided into 5 playing positions: goalkeepers (n = 24), defen…