جستجوی مقالات مرتبط با کلیدواژه « عملکرد سرعتی » در نشریات گروه « تربیت بدنی »

The ability to attain high level of speed is an essential component of success in many sports fields. However, physical qualities that underpin this ability remain unclear. The purpose of this study was to investigate the role of leg stiffness and vertical stiffness in predicting sprint running.

50 healthy females were selected among physical education students. The required kinetic and kinetic data were collected in three dimensions. The kinetic and kinematic variables rrunning skill was used to measure both stiffness variables. A multivariate regression model was used to examine the possibility of predicting running speed using leg stiffness and vertical stiffness.

The results of multiple regression showed that there is a significant relationship between the two-leg stiffness and vertical stiffness with mean running speed (R = 0.671), and these two variables can predict 42% of Average speed variation (Adj. R square=0.426).

The results of the present study showed that the ability of individuals to sprint running is likely to be significantly dependent on leg stiffness and vertical stiffness. The results of this study can provide important information for designing training programs and talent detection for trainers and specialists in this field.

Background and Recently high intensity interval training (HIIT) has become an interesting study field for research. However, few studies have been conducted in this domain.Hence, the aim of the present study was to evaluate the effect of two weeks of high intensity interval training (HIIT) on some cardiovascular indices, anaerobic power output, jumping andsprint performances in active female students. 20 female students of physical education voluntarily participated as subjects for the study. Subjects were randomly divided into experimental and control groups The pretests including estimating VO2max, resting blood pressure, restingheart rate, power output with RAST and Wingate test, 20 meter sprinting, and height of squat jump and countermovement jump were taken in one week. Then, the experimental group wasexposed to 2 weeks of HIT for 5 days per week in addition to their routine physical activities. After 48 hours of the last training session, post-tests were administered in both groups. To analyzethe data, independent T-test with a significance level of p 0.05 was used. Our findings showed significant increases in VO2max, peak, average and minimum power on RAST test and a significant reduction in sprinting time (p<0.05). However, resting blood pressure, resting heart rate, power output with Wingate test, height of squat jump and countermovement jump and also leg elasticity index did not significantly change after training. According to results of the present study, it seems that two weeks high intensity interval training can be effective for improving VO2max, sprint performance and increasing anaerobic power in a short time for sports in which running is essential.

The purpose of this study was to investigate the effect of four weeks interval training with creatine supplementation on body composition and sprint performance in amatory female swimmers.

Subjects
consist of 30 female from Ahvaz City (average age: 22/10 ± 1/41 , mean weight: 57 ± 6/31 kg) were selected and randomly divided in three equal groups of supplement, placebo and control. The subjects in supplement group ingested 20gr (2×10gr per day) creatine supplement per day for five days (loading phase) and then ingested 2gr per day for 25 day (maintenance phase). In placebo group, the subjects ingested the same dose of placebo at the same time. The supplement and placebo groups participated in swimming interval training by 85_90% of maximum heart rate for four weeks. The control group didn’t ingested supplement and didn’t participate in training. body compositions factors of subjects were evaluated by performed body composition test and for evaluation the sprint performance, subjects performed the 25m swimming test. All of the subjects performed these tests before and after 4 weaks training.

The results suggested that four weeks interval training with creatine supplementation lead to no significant changes in body compositions factors in supplement and placebo groups. But four weeks interval training with creatine supplementation lead to significant changes in sprint performance in supplement and placebo groups.

Therefore these results suggest that creatine supplementation lead to increase in muscle creatine reserve, improvement in ATP-Pc system and then lead to improvement in intensive short distance performance. In the other hand, the subjects were amatory and one of the factors that improved the records of sprint performance (in tow groups) may be learning and effects of training.

The purpose of this study was to investigate the effects of short term creatine monohydrate as an ergogenic supplement on the sprint performance and muscular strength of wrestlers. 20 wrestlers were selected randomly and divided into two groups. One group was placebo group (control) and the other group was creatine supplement group (experimental). In a double blind project, subject's speed running, perseverance in repeated alternative speeds and muscular strength (with 1-RM in knee extension) were measured before creatine and placebo as pretest, and after that as posttest. Creatine and placebo were used for 7 days (20 grams creatine monohydrate per day by experimental group and 20 (g/d) dextrose polymer as placebo by control group).The data were analyzed by correlated t – test (for each group) and independent t-test (between two groups). The results showed that short term use of creatine supplement had a significant effect on short term running (20 and 40 meters), long term running (60 and 100 meters), interval speed endurance running (30 fast running in 5 seconds with 10 seconds of rest between each running) and muscle strength (1-RM in knee extension) of wrestlers (p<0.05).