The impact of Dr Barry Sears’ diet on employee stress: a preliminary study

Work stress can lead to health and performance problems for employees who are unable to cope with it. The main objective of this study was to investigate whether Dr Sears’ diet affects employees’ stress. Data was collected from a sample of 100 employees who were employed by different companies in the broader area of Attica, once a week for a period of three weeks. Of those who participated in the study 56% were male. The results showed that Dr Sears’diet had a beneficial effect on participants’ stress levels, which decreased from the first week of implementation and continued to decline during the second and third week. Future research should focus on long-term effects of this diet on employee behavior related to motivation and performance, to deepen our understanding of the significant role of nutrition at work

Effect of combined uphill-downhill sprint training on kinematics and maximum running speed in experienced sprinters

This study examined the effects of sprint running training on sloping surfaces (3°) in experienced sprinters using selected kinematic variables. Twelve experienced sprinters were randomly allocated to two training groups (combined uphill–downhill and horizontal). Pre- and post-training tests were performed to examine the effects of six weeks of training on maximum running speed, step rate, step length, step time, contact time, braking and propulsive phase of contact time, flight time and selected postural characteristics during a step cycle in the final steps of a 35m sprint test. In the combined uphill–downhill training group, maximum running speed was substantially greater (from 9.08 ± 0.90 m s-1 to 9.51 ± 0.62 m s-1; p <0.05) after training by 4.8%; step rate, contact time, step time and concentric phase was not modified. There were no significant changes in maximal speed or sprint kinematics in the horizontal training group. Overall, the posture characteristics did not change with training. The combined uphill–downhill training method was substantially more effective in improving the maximum running speed in experienced sprinters than a traditional horizontal training method

Effects of conditioning hops on drop jump and sprint performance: a randomized crossover pilot study in elite athletes

BACKGROUND: It has previously been shown that conditioning activities consisting of repetitive hops have the potential to induce better drop jump (DJ) performance in recreationally active individuals. In the present pilot study, we investigated whether repetitive conditioning hops can also increase reactive jump and sprint performance in sprint-trained elite athletes competing at an international level. METHODS: Jump and sprint performances of 5 athletes were randomly assessed under 2 conditions. The control condition (CON) comprised 8 DJs and 4 trials of 30-m sprints. The intervention condition (HOP) consisted of 10 maximal repetitive two-legged hops that were conducted 10 s prior to each single DJ and sprint trial. DJ performance was analyzed using a one-dimensional ground reaction force plate. Step length (SL), contact time (CT), and sprint time (ST) during the 30-m sprints were recorded using an opto-electronic measurement system. RESULTS: Following the conditioning activity, DJ height and external DJ peak power were both significantly increased by 11 % compared to the control condition. All other variables did not show any significant differences between HOP and CON. CONCLUSIONS: In the present pilot study, we were able to demonstrate large improvements in DJ performance even in sprint-trained elite athletes following a conditioning activity consisting of maximal two-legged repetitive hops. This strengthens the hypothesis that plyometric conditioning exercises can induce performance enhancements in elite athletes that are even greater than those observed in recreationally active athletes.. In addition, it appears that the transfer of these effects to other stretch-shortening cycle activities is limited, as we did not observe any changes in sprint performance following the plyometric conditioning activity

Target Constraints Influence Locomotion Pattern to the First Hurdle

The study examined to what extent the manipulation of hurdle height (0.76-m hurdle, low hurdle 0.50 m, and white stripe) would affect visual regulation strategies and kinematic reorganization when approaching the first hurdle. In addition, the impact of constraints as a training tool in terms of creating movement patterns functional for and representative of competitive movement models was assessed. The approach phase to the first hurdle of 13 physical education students with no previous experience in hurdling was video recorded and analyzed. Emergence of different footfall variability curves and movement coordination patterns suggests that participants interact differently with features of the performance context. Contrary to the white stripe, the hurdle height required participants to initiate regulation and distribute adjustments over a larger number of steps, and afforded the preparation for takeoff in order to clear the hurdle. In task design, manipulation of task constraints should offer valuable information regarding the dynamics of movement. © 2022 Human Kinetics, Inc

Relative age effect: A systematic discrimination against biologically younger athletes

Physical differences associated with birth-date among athletes of the same selection year have been described as the Relative Age Effect (RAE). The aim of this study was to examine whether RAE still exists in soccer and running sport disciplines as well as to evaluate its progress among different gender, age, and sport context and if it has an effect on performance. Using official archives of the international sports&apos; associations (World Athletics-UEFA), birthdates and performance were collected for 7,226 athletes (4,033 males; 3,198 females) who participated in soccer and running events. A chi-square test was used to assess differences between observed and expected birth date distributions. The study showed an over-representation of athletes born in the first quarter of the selection year for both soccer and running events. RAE is more obvious in younger age groups and in sports that require higher explosive speed, strength, power and anaerobic capacity such as soccer and short distance sprints. It was also found that RAE is associated with performance. In conclusion, athletes of younger age groups with greater biological age have a physical advantage in explosive sports (i.e. soccer and short distance running) that probably does not predict their future development. © 2021 Wydawnictwo Naukowe Uniwersytetu Szczecinskiego. All right reserved

Locomotor control in the long jump approach run in young novice athletes

We examine the presence of visually regulated control in young, novice long jumpers as they approach the takeoff board. The approach run of 27 novice jumpers (age 12-13 years) practising jump training for a short period was video-recorded during competition. Findings revealed that young, novice participants adjust the length of the final steps of their approach run, suggesting the presence of visual control. Step regulation commenced on the fifth and fourth step from the board for boys and girls respectively. Their pattern of footfall variability was found to be comparable to that of skilled long jumpers, although young, novice participants presented slightly higher variability. It appears that even a limited period of jump training may contribute to a more consistent run-up as well as to smaller takeoff error, offsetting the limitations imposed by the partially developed cognitive abilities and perceptual awareness of young athletes. © 2013 © 2013 Taylor &amp; Francis

Acute Effects of Stretching on Flexibility, Power and Sport Specific Performance in Fencers

Elite athletes are eager to perform to the best of their ability, regardless of different warm-up stretching techniques used before training or competition which actually help or hinder specific performance variables. The aim of this study was to investigate the acute effects of static or ballistic stretching on flexibility and leg power characteristics of fencing performance in fencers of both genders. Ten male and ten female international level fencers participated in this study. Each subject performed static or ballistic stretching (3 sets of 20 sec) on three muscles of the lower limbs on separate days. Flexibility, squat jump, countermovement jump, drop jump, time and power of lunge and shuttle run test were measured before and after different stretching interventions. Neither static nor ballistic stretching exercises affected flexibility, jumping ability and leg functional fencing performance tests. Moreover, stretching conditions did not affect differently. The results of this study suggest that static or ballistic stretching in the later stages of a general warm-up normally used before training or competition does not hinder specific performance in fencing. Consequently, fencers can continue performing any type of stretching before training or competition at their preference. © 2010, Versita. All rights reserved

Sprinting and dribbling differences in young soccer players: a kinematic approach

Sprinting and dribbling a ball are considered essential for success in team sports, such as soccer. The purpose of the present study was to examine straight line (SL) and changes of direction (COD) sprinting and dribbling abilities after a standing and a flying starting position. Twelve amateur U12 male soccer players participated in the study. The participants were tested in four different sprinting conditions. The first consisted of 15 m SL sprinting and dribbling test by standing position; the second consisted of 15 m SL sprinting and dribbling test by flying start. The third condition consisted of 15 m COD sprinting and dribbling test by standing position, and the fourth condition consisted of 15 m COD sprinting and dribbling test by flying start. T-tests analysis indicated significant differences between SL sprinting and dribbling sprinting tests (P &lt; 0.05) and between standing and flying start positions (P &lt; 0.05). Step frequency was higher for sprinting tests (P &lt; 0.05). Moreover, the results showed that step length was longer when players had a standing position (P &lt; 0.05). These findings emphasize the importance for trainers to add parts without ball, focused on the development of certain fitness and running components. © 2021 Informa UK Limited, trading as Taylor &amp; Francis Group

Acquisition of the long jump skill, using different learning techniques

This study examined the contribution of instructional self-talk and observational learning on the development of long jump technique. Sixty-nine beginner athletes were randomly assigned to four groups: &apos;self-talk&apos;, &apos;video&apos;, &apos;self-talk + video&apos; and control group. All groups performed 24 practice sessions, consisting of a cognitive intervention program in the form of either instructional self-talk or observational learning, or a combination of both, and the practice of specific drills. A significantly higher performance improvement was recorded for the self-talk group in post test, whereas when kinematic variables of the motor skill (center of mass displacement) were assessed, &quot;observational learning&quot; proved to be more effective. The findings of the current study suggest that young, beginner athletes, participating in complicated tasks, may benefit from cognitive intervention techniques, through enhanced attentional focus on the most critical elements of the motor skill. © 2013 Human Kinetics, Inc

Anthropometric parameters and leg power performance in fencing. Age, sex and discipline related differences [Caractéristiques anthropométriques et puissance en escrime : relation avec l’âge, le sexe et l&apos;arme]

Objective The aim of this study was to compare anthropometric, body composition, and leg power performance in male and female, elite, and national fencers of all age competitive groups and discipline practiced. Subjects and methods A total of 125 fencers (mean ± SD; age 20.6 ± 6.7 years, height 173.2 ± 9.2 cm and body mass 64.7 ± 4.7 kg) participated in this study. Anthropometric measurements were taken before participants performed squat, countermovement, drop, and standing log jump. Results Significant differences were identified between male and female for height (177.6 ± 8.9 cm vs. 167.9 ± 6.2 cm, P &lt; 0.001), body mass (70.4 ± 11.9 kg vs. 57.6 ± 7.0 kg, P &lt; 0.001), arm span (181.8 ± 9.7 cm vs. 168.8 ± 7.2 cm, P &lt; 0.001), leg length (88.9 ± 6.4 cm vs. 81.7 ± 4.3 cm, P &lt; 0.001) and body mass index (22.2 ± 3.0 vs. 20.5 ± 2.1, P &lt; 0.001) and for long jump (202.2 ± 34.7 cm vs. 167.4 ± 23.5 cm, P &lt; 0.05), squat jump (26.5 ± 7.13 cm vs. 19.9 ± 4.00 cm, P &lt; 0.05), counter movement jump (30.1 ± 7.4 cm vs. 21.7 ± 4.5 cm, P &lt; 0.05), drop jump (28.4 ± 9.5 cm vs. 22.3 ± 6.4 cm, P &lt; 0.05) and reaction strength index (0.90 ± 0.4 vs. 0.66 ± 0.3, P &lt; 0.05), respectively. Significant differences in jumping performance were observed between the 14–17 years old and the &gt; 20 years old group for long jump (179.2 ± 30.8 cm vs. 205.2 ± 33.9 cm, P &lt; 0.05), squat jump (21.9 ± 5.3 cm vs. 26.2 ± 7.8 cm, P &lt; 0.05), counter movement jump (25.1 ± 5.9 cm vs. 29.0 ± 8.6 cm, P &lt; 0.05), drop jump (19.01 ± 7.0 cm vs. 25.2 ± 6.7 cm, P &lt; 0.05) and reaction strength index (0.69 ± 0.35 vs. 0.96 ± 0.32, P &lt; 0.05) and between the 18–20 years old &gt; and the 20 years old group for long jump (174.0 ± 30.3 cm vs. 205.2 ± 33.9 cm, P &lt; 0.05), squat jump (22.6 ± 6.1 cm vs. 26.2 ± 7.8 cm. P &lt; 0.05), countermovement jump (24.9 ± 7.1 cm vs. 29.0 ± 8.6 cm, P &lt; 0.05), drop jump (20.9 ± 6.8 cm vs. 25.2 ± 6.7 cm, P &lt; 0.05) and reaction strength index (0.71 ± 0.4 vs. 0.96 ± 0.32, P &lt; 0.05), respectively. Elite fencers performed better in squat (27.3 ± 7.1 cm vs. 22.9 ± 6.5 cm, P &lt; 0.05), countermovement jump (30.5 ± 8.00 cm vs. 25.5 ± 7.2 cm, P &lt; 0.05) and long jump (203.8 ± 38.9 cm vs. 183.2 ± 33.6 cm, P &lt; 0.05) than national level fencers. Significant differences were observed for drop jump contact time between foil and epee groups (0.32 ± 0.01 ms vs. 0.28 ± 0.01 ms, P &lt; 0.05), respectively. Conclusion The observed differences in anthropometric measurements and leg power performance will facilitate the identification of the most suitable athletes and highlighted specific power abilities that could support the technical drills in competitive fencing. © 2017 Elsevier Masson SA