Relationships between Strength and Step Frequency with Fatigue Index in Repeated Sprint Ability

Force−velocity profile (FVP) and repeated-sprint ability (RSA) tests are indicators of physical capacities in most team sport players. The purpose of this study was to examine the stride kinematics during a repeated-sprint ability (RSA) test and to analyze the relationship between Bosco’s force−velocity profile (FVP) and RSA performance in elite female field hockey players. Thirteen elite-female players performed both RSA (six 30 m maximal sprints) and jumping (CMJ weighted and body weight) tests. Sprinting time fatigue indexes during a 30 m RSA test were correlated with step frequency fatigue indexes (r > 0.7; p < 0.01). CMJ50 showed a large relationship with sprint time fatigue indexes. FV50 showed a very large relationship with sprint time fatigue indexes (r > 0.7; p < 0.01), and a large relationship with the step frequency fatigue indexes (r > 0.5; p < 0.05). This study highlighted two possible ways to improve fatigue indexes in RSA, with the aim of maximizing the distances covered at high-intensities during the matches: (a) strength training and (b) focusing on step frequency during speed training.

Maturity Has a Greater Association than Relative Age with Physical Performance in English Male Academy Soccer Players

This study aimed to: (1) examine differences in physical performance across birth-quartiles and maturity-status, and (2) determine the relationships among relative age, maturation and physical performance in young male soccer players. The sample included 199 males aged between 8.1 and 18.9 years, from two professional soccer academies in the English Football League. Data were collected for height, weight, self-reported biological parent heights, 30 m sprint time and countermovement jump (CMJ) height. Relative age was conveyed as a decimal, while maturity status was determined as the percentage of predicted adult height (PAH). There were no significant differences in any measure between birth quartiles, however early maturers outperformed on-time and later maturers in most performance measures. Pearson-product-moment correlations revealed that maturation was inversely associated with 30 m sprint time in U12 to U16 (r = −0.370–0.738; p < 0.05), but only positively associated with CMJ performance in U12 (r = 0.497; p < 0.05). In contrast, relative age was unrelated to sprint performance and only significantly associated with superior CMJ performance in U16. This study indicates that maturity has a greater association with sprint performance than relative age in English male academy soccer players. Practitioners should monitor and assess biological maturation in young soccer players to attempt to control for the influence on physical performance, and avoid biasing selection on absolute performance rather than identifying the most talented player.

The effects of a sled push at different loads on 20 metre sprint time in well-trained soccer players

This study determined the effects of a single sled push at different loads on sprint performance in competitive male soccer players. Twenty male competitive outfield soccer players (age 19.6±1.3y, body mass 73.6±8.2kg) were split into experimental (n=10) and control groups. In the experimental group, 20m linear sprint time was measured immediately before and 5, 6 and 7minutes after the sled push with either 50 or 100% body mass. The control group performed the 20m sprints only. A repeated measures ANOVA comparing control and experimental groups revealed no effects of time, group or time by group interaction for either experimental condition (all P>0.05). The repeated measures ANOVA compared the experimental conditions revealed effects of time (P=0.034) and group (P=0.002), but not time by group (P>0.05). The effects sizes demonstrated within group effects on sprint time that were small to moderate (-0.26 to 0.71) and trivial to small (-0.31 to 0.09) for the 50% and 100% body mass condition, respectively. These findings demonstrate that a sled push has no significant effect on 20 m sprint time in competitive footballers. If coaches continue to prescribed a sled push before sprinting, a single 15 m push with 50% body mass could have positive benefits.

The Relationship Between Repeated Sprint Performances and 50m and 100m Swimming Degrees of Swimmers

Aim: The aim of this study is to investigate the relationship between short distance swimming performance and repeated sprint ability in swimmers. Methods: 12 male swimmers between the ages of 14-18 from Denizli Pamukkale University Swimming Sports Club Performance team voluntarily participated at this study. Freestyle swimming time of the subjects was measured by using Casio stopwatch. 10x15-m, 50-m and 100-m freestyle swimming degrees of swimmers were recorded. The ideal sprint time (IS), the total sprint time (TS) and the performance decrement (PD) were determined after repeated sprint test (RST). Lactate levels were recorded at the end of each test. The Borg scale was used to determine the perceived difficulty level. For the statistical analysis Pearson’s correlation was used to determine the correlations between 50- m and100-m freestyle swimming time and swimming times obtained at the end of RST (IS, TS, PD). Results: Significant relationships were found between the 50-m and 100-m swimming performance (p<0.01). Significant correlations were found between the IS and the TS and the 50-m swim results (p<0.01) and also the 100-m swim results (p<0.05). Significant correlations were found between the 50-m lactate values and 100-m lactate values (p<0.05). Significant relationships were found between 10x15-m RST lactate values and 50-m lactate values (p<0.05). Moreover, strong relations were found between the 10x15-m RST lactate values and 100-m lactate values (p<0.01). Conclusion: This study has shown that repeated sprint ability as well as higher anaerobic capability as reflected by the short distance. Keywords: swimming, repeated sprint ability, short distance swimming performance

Effects of time-of-day on repeated sprint performance of aromatherapy massage applied young futsal players

Background: Different protocols are applied in order to increase the performance of athletes in sports that include high-intensity activities such as futsal. Massage protocols applied before or after exercise are frequently used for performance improvement. The differences in oils used in the massage and the time of day may vary performance levels of the futsal players. Aim: This study was planned to determine the effects of time-of-day on repeated sprint performance of aromatherapy massage applied young futsal players. Methods: Twelve male athletes between the age of 18-25, who exercised regularly for five days a week and played futsal for at least 4 years, participated in the study (age, 20.50± 1.78 years; height, 171.92± 2.23 cm; 67.92 ± 2.42 kg; BMI 23.06±.77). The research protocols consisted of three different protocols as single group, non-massage protocol (NM), Swedish massage applied protocol (SM), and aromatherapy massage applied protocol (ATM). In addition, three measurements were taken for each protocol and measurements were made at different times of the day (09.00 in the morning; 13.00 in the afternoon; 17.00 in the evening). After each measurement, the Repetitive Sprint Test (RST) (6x20m) measurements of the athletes were taken. While evaluating RST results, the fastest sprint time (FS), total sprint time and percent change (PC) from the first sprint to the last sprint were calculated. Results: It was determined that there was a statistical difference between RST values observed at different times of the day after NM, SM and ATM protocols. In addition, among all protocols, ATM protocol was found to be more effective. Conclusion: It was determined that ATM had a positive effect on RST performance compared to NM and SM protocols and the ATM protocol applied in the evening was more effective than the ATM protocol applied in the morning and afternoon. Keywords: Futsal, Diurnal Variation, Aromatherapy Massage, Repetitive Sprint.

The Relationship Between Repeated Sprint Performances and 50m and 100m Swimming Degrees of Swimmers

The aim of this study is to investigate the relationship between short distance swimming performance and repeated sprint ability in swimmers. 12 male swimmers between the ages of 14-18 from Denizli Pamukkale University Swimming Sports Club Performance team voluntarily participated at this study. Freestyle swimming time of the subjects was measured by using Casio stopwatch. 10x15-m, 50-m and 100-m freestyle swimming degrees of swimmers were recorded. The ideal sprint time (IS), the total sprint time (TS) and the performance decrement (PD) were determined after repeated sprint test (RST). Lactate levels were recorded at the end of each test. The Borg scale was used to determine the perceived difficulty level. For the statistical analysis Pearson’s correlation was used to determine the correlations between 50- m and100-m freestyle swimming time and swimming times obtained at the end of RST (IS, TS, PD). Significant relationships were found between the 50-m and 100-m swimming performance (p<0.01). Significant correlations were found between the IS and the TS and the 50-m swim results (p<0.01) and also the 100-m swim results (p<0.05). Significant correlations were found between the 50-m lactate values and 100-m lactate values (p<0.05). Significant relationships were found between 10x15-m RST lactate values and 50-m lactate values (p<0.05). Moreover, strong relations were found between the 10x15-m RST lactate values and 100-m lactate values (p<0.01). In conclusion, this study has shown that repeated sprint ability as well as higher anaerobic capability as reflected by the short distance. Keywords: swimming, repeated sprint ability, short distance swimming performance

A cloth facemask increased ratings of perceived exertion and reduced affect, but did not affect sprint or muscular performance during training in athletes

During the COVID-19 pandemic, the necessity of using face masks during sports is likely balanced by coaches and athletes between the risk of infection and their impact on exercise performance. To inform this decision, we aimed to test the effects of wearing a cloth face mask on exercise performance and subjective responses during training of track and field athletes. Participants (n=10) performed two training sessions with and without a 3-layered cloth mask in a randomized, counterbalanced, crossover design. The training session was designed to simulate the specific demands of the sport that the athletes practiced. The sprint protocol consisted of performing five maximal 30 m sprints, with a passive 4-min interval between runs. Performance variables (sprint time, acceleration) were calculated using the sprint time data. Jump performance was assessed pre- and post-sprints using a countermovement vertical jump. Throughout the training session, ratings of perceived exertion (RPE) and affect were collected. There was no evidence of condition x time interactions for sprint time (P=0.21) or acceleration (P=0.47). There was weak evidence of an effect of condition (P=0.05) on RPE, though no evidence of a condition x time interaction (P=0.35). There was moderate evidence of a condition x time interaction (P=0.02) for affect, with lower ratings following sprints 3, 4 and 5 when using the mask. These findings suggest that wearing a mask may negatively impact subjective feelings of training without necessarily harming sprint performance. During an unmitigated epidemic such as in Brazil, the protection against SARS-CoV-2 infection associated with wearing a face mask appears to outweigh the increased discomfort and perception of effort related to this safety tool.

The effects of different intra-set velocity loss thresholds on lower-limb adaptations to resistance training in young adults: A systematic review and meta-analysis

Background: The level of effort seems to play a key role in determining neuromuscular adaptations; however, less is known regarding the optimal dose-response for intra-set levels of effort on chronic resistance training (RT) adaptations. Objective: We aimed to synthesize the current literature on chronic RT adaptations in response to different intra-set velocity loss (VL) thresholds in the back squat exercise. We investigated changes in muscle strength, muscular endurance, sports-related physical performance, and muscle hypertrophy outcomes during resistance exercise to establish optimal dose-response relationships in physically active individuals.Methods: We conducted a literature search using PubMed (Medline), Web of Science™, Scopus, and Cochrane up to April 2021, with no restriction on year of publication. The inclusion criteria were based on the PICO strategy. A random-effect meta-analysis was performed to determine the standardized mean differences (SMD ± 95% confidence intervals) for different intra-set VL thresholds (low VL [&lt; 15%], moderate VL [≥ 15% and &lt; 30%], and high VL [≥ 30%]) in RT on maximum muscular strength, bar velocity against submaximal loads, endurance against a given load, countermovement jump height, running sprint time, and muscle hypertrophy. Results: A total of 4,031 articles were found and 11 studies met our eligibility criteria. Pooled results revealed improvements between pre- and post-training intervention in 1RM strength (SMD = 0.78; p &lt; 0.001); bar velocity outputs (light-loads [SMD = 0.79; p &lt; 0.001] and heavy-loads [SMD = 2.08; p &lt; 0.001]); endurance against a given load (SMD = 1.21; p &lt; 0.001); countermovement jump height (SMD = 0.50; p &lt; 0.001); running sprint time (SMD = - 0.28; p = 0.001); and muscle hypertrophy (SMD = 0.31; p = 0.05), with no significant difference between VL thresholds (p &gt; 0.05). However, low VL elicited greater within-group SMD for 1RM strength than moderate and high VL thresholds (SMD = 0.93; 0.72; and 0.75; for low, moderate, and high VL thresholds, respectively). Low and moderate VL thresholds resulted in greater within-group SMD than high VL thresholds for velocity against light loads (SMD for low VL = 0.89; moderate VL = 0.90; high VL = 0.59); countermovement jump height (SMD for low VL = 0.51; moderate VL = 0.58; high VL = 0.36); and running sprint time (SMD for low VL = -0.49; moderate VL = -0.32; high VL = -0.09). Moderate and high VL thresholds induced higher within-group SMD for muscle hypertrophy than low VL (SMD for low VL = 0.14; moderate VL = 0.40; high VL = 0.44). Conclusions: Low to moderate VL thresholds may provide more effective and efficient training stimuli for improving performance in strength-power tasks, due to the similar or even greater chronic adaptations achieved compared with high VL, despite the lower number of repetitions performed during the RT program. Conversely, moderate to high VL may provide more favorable training stimuli for inducing muscle hypertrophy. Strength coaches may apply these dose-response trends to design optimal RT stimuli based on their specific training goals. Protocol registration: The study protocol was registered at the International Prospective Register of Systematic Reviews (PROSPERO) database (CRD42020189321).

Effect Of Abc Running Drill on the 50 Meter Sprint Of Students

The purpose of this study was to determine whether there is an effect of the abc running drill on the ability to sprint 50 meters. The research was conducted using an experimental method with one group pretest-posttest design. At the initial stage, data collection was carried out to determine the initial conditions of students' sprint abilities which included the ability of basic running techniques and 50 meters sprint speed. Data collection techniques using observation and tests. Observations were made by observing basic squat start techniques, running techniques and finishing techniques while the test was used to take a sprint time of 50 meters. The instrument used in the study used a rubric for the assessment of the 50 meter sprint ability. To calculate the data obtained, the Wilcoxon nonparametric test data analysis was used. Based on the results of data analysis, the Asym.Sig. (2-tailed) <0.05, then Ha is accepted. Asym.Sig. (2-tailed) (0.000 <0.05) means that there is an effect of abc running drill on the ability of students to sprint 50 meters.Keywords: Abc Running Drill, 50 Meter Sprint, Students

Relationship of the knee extensor strength but not the quadriceps femoris muscularity with sprint performance in sprinters: a reexamination and extension

Purpose This study examined the relationships of knee extensor strength and quadriceps femoris size with sprint performance in sprinters. Methods Fifty-eight male sprinters and 40 body size-matched male non-sprinters participated in this study. The knee extensor isometric and isokinetic strengths were measured using a dynamometer. The isokinetic strength measurements were performed with slow and fast velocities at 60°/s and 180°/s, respectively. The quadriceps femoris muscle volume (MV) was measured using magnetic resonance imaging. The relative knee extensor strengths and quadriceps femoris MV were calculated by normalizing to body mass. Results Absolute and relative knee extensor strengths during two velocity isokinetic contractions, but not during isometric contraction, were significantly higher in sprinters than in non-sprinters (P = 0.047 to < 0.001 for all). Such a significant difference was also observed for relative quadriceps femoris MV (P = 0.018). In sprinters, there were positive correlations between all three knee extensor strengths and quadriceps femoris MV (r = 0.421 to 0.531, P = 0.001 to < 0.001 for all). The absolute and relative strengths of the fast-velocity isokinetic knee extension correlated negatively with personal best 100-m sprint time (r = −0.477 and −0.409, P = 0.001 and < 0.001, respectively). In contrast, no such significant correlations were observed between absolute and relative quadriceps femoris MVs and personal best 100-m sprint time. Conclusions These findings suggest that despite the presence of the relationship between muscle strength and size, the knee extensor strength may be related to superior sprint performance in sprinters independently of the quadriceps femoris muscularity.