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ABSTRACT: The purpose of the study was to find out the “Efficacy of Circuit resistance training and football skill based drill training on speed of college football players”.

To achieve this purpose of the study, sixty intercollegiate football players from SRM University, Kanchipuram were selected at random as subjects. The age of the players ranged from 18 to 25 years. The selected players were divided into two experimental groups and a control group. Group-I underwent circuit resistance training, Group-II underwent Football skill based drill training and Group III acted as control that did not participate in any special training program apart from their regular activities. The speed was selected as dependent variable and it was tested by 50 meters run and the performance was recorded in seconds. The pre and post test data were collected after the stipulated training period of twelve weeks.

The analysis of co variance was applied to find out the significant differences if any among the groups. If significant difference found among the groups the Scheffe’s post hoc test was applied to identify the paired mean difference between the groups. The results revealed that the selected training program have produced the significant improvement on speed.
Reference

Albert Jayasingh, Dr. Jesudoss, and J. Samuel , Research Scholar. 2015. International Journal of Physical Education Sports Management and Yogic Sciences. Volume : 5, Issue : 3

Abstract: Resisted sprinting (RS) is a popular training method used to enhance sprinting performance in youth. However, research has only explored the effects of forward RS (FRS) training. We examined the effects of FRS and backward RS (BRS) and compared these with a traditional physical education curriculum (CON). One hundred fifteen boys (age 13–15 years) were matched for maturity and allocated to either an FRS (n = 34), BRS (n = 46), or CON (n = 35) group. Training groups towed progressively overloaded sleds (20–55% body mass) 2 d·wk−1 for 8 weeks. Pre-training and post-training data were collected for sprinting times over 10 and 20 m, countermovement jump (CMJ) height, and leg stiffness (KN). Performance remained unchanged for the CON group (all p > 0.05), whereas all variables significantly improved (p < 0.05) after BRS, and all but 10-m performance improved after FRS. Compared with the CON, BRS and FRS significantly (p > 0.05) improved CMJ (Effect size [ES] = 0.67 and 0.38) and KN (ES = 0.94 and 0.69), respectively. No differences were found between training groups. The probabilities of improving sprinting performance after BRS (∼70%) were on average ∼10 and ∼8% better than the FRS and CON groups, respectively. The BRS and FRS showed similar probabilities of improving CMJ (75 and 79%) and KN (80 and 81%), respectively, over the CON group. It seems that BRS may be a means to improve sprint performance, and regardless of direction, RS seems to be a beneficial method for improving jumping height and leg stiffness in youth male athletes.

Reference

Uthoff, A, Oliver, J, Cronin, J, Winwood, P, Harrison, C, and Lee, JE. Resisted sprint training in youth: the effectiveness of backward vs. forward sled towing on speed, jumping, and leg compliance measures in high-school athletes. J Strength Cond Res XX(X): 000–000, 2019

Abstract – Purpose: Footedness as a predictor of brain hemispheric dominance cause performance differences in movement and sports performance. This study aimed to investigate the 30 m sprint speed difference between unilateral and bilateral foot dominance in 156 male and 37 female athletes.

Material Method: It was assumed that all participants exerted maximum effort during 30 m sprint test in the entrance examination for schools of physical education and sports. The participants with right and left foot dominance were accepted as “unilateral footed” while participants kicking the ball with two foot were recognized as “bilateral footed”. For testing differences between two groups Mann Whitney U tests were used.

Results: There was only significant difference in the second attempt of 30 meters sprints between unilateral and bilateral footed male participants. Bilateral footed males were 2.81% faster than unilateral footers. Sprint speed difference was 11.97% for first trial and 10.43% for second trial in between unilateral and bilateral footed female participants. However, this difference was statistically insignificant due to lower number of bilateral athletes in our study.

Conclusion: Unilateral and bilateral foot dominance can be useful criteria in the selection of talented sprinters and in the planning and monitoring of training.

Reference

Muzaffer Selçuk, Mehmet Akif Ziyagil, Orhan Şener. The Effect of Unilateral and Bilateral Foot Dominance on Sprinting Speed of Young Athletes. Journal of Education and Training Studies. Vol. 7, No 4 (2019)

Abstract: Resisted sprinting (RS) is a popular training method used to enhance sprinting performance in youth. However, research has only explored the effects of forward RS (FRS) training. We examined the effects of FRS and backward RS (BRS) and compared these with a traditional physical education curriculum (CON). One hundred fifteen boys (age 13–15 years) were matched for maturity and allocated to either an FRS (n = 34), BRS (n = 46), or CON (n = 35) group. Training groups towed progressively overloaded sleds (20–55% body mass) 2 d·wk−1 for 8 weeks. Pre-training and post-training data were collected for sprinting times over 10 and 20 m, countermovement jump (CMJ) height, and leg stiffness (KN).

Performance remained unchanged for the CON group (all p > 0.05), whereas all variables significantly improved (p < 0.05) after BRS, and all but 10-m performance improved after FRS. Compared with the CON, BRS and FRS significantly (p > 0.05) improved CMJ (Effect size [ES] = 0.67 and 0.38) and KN (ES = 0.94 and 0.69), respectively. No differences were found between training groups. The probabilities of improving sprinting performance after BRS (∼70%) were on average ∼10 and ∼8% better than the FRS and CON groups, respectively. The BRS and FRS showed similar probabilities of improving CMJ (75 and 79%) and KN (80 and 81%), respectively, over the CON group. It seems that BRS may be a means to improve sprint performance, and regardless of direction, RS seems to be a beneficial method for improving jumping height and leg stiffness in youth male athletes.

Reference

Uthoff, A, Oliver, J, Cronin, J, Winwood, P, Harrison, C, and Lee, JE. Resisted sprint training in youth: the effectiveness of backward vs. forward sled towing on speed, jumping, and leg compliance measures in high-school athletes. J Strength Cond Res XX(X): 000–000, 2019

The aim of this research was to determine which kinematic parameters generate the maximum sprint speed of the world’s fastest sprinter, Usain Bolt. The biomechanical parameters of a double sprint step, using a 2D kinematic analysis under conditions of the realization of its maximum velocity were analyzed. The APAS computer system was used for the kinematic analysis. The data was recorded with three digital cameras CASIO EX-F1 with a frequency of 300 Hz, while the cameras were connected to one another and synchronized. The measurements were performed at the international athletics competition IAAF World Challenge in Zagreb, Croatia. Bolt reached a maximum speed of 12.42 m·s-1 in the section between 70 and 90 meters. His average stride length in this section was 2.70 m at an average frequency of 4.36 strides/s. His average contact time was 0.86 s and the average duration of his flight phase was 0.145 s. He developed a maximum vertical ground reaction force of 3956.74 N. This force corresponds to 4.1 times the weight of the athlete. The ratio between his braking and propulsion phase was 37.3% : 62.7%, which is a good indicator of an economical running technique. The maximum speed of Usain Bolt is a combination of optimal anthropometric characteristics, motor abilities, and an extremely rational technique of sprinting gait.

Reference

FACTA UNIVERSITATIS: series: Physical Education and Sport. Vol. 17, No. 1, 2019 https://doi.org/10.22190/FUPES190304003C

Abstract: Ground contact time (GCT) and vertical ground reaction force (VGRF) are key variables with Video Measures of Running Ground Contact Times and Vertical Ground Reaction Forcesregards to running performance, metabolic rate, and musculoskeletal stresses. However, there are few field-based methods with acceptable accuracy to quantify these variables in comparison to a laboratory force plate standard. The development of commercially available high-speed video cameras (HSC) may provide a cost-effective method for determining these variables during over-ground running. PURPOSE: To validate video-based measures of GCT and VGRF compared to a laboratory force plate. METHODS: 20 subjects (13 males, height = 1.76±0.07m, mass = 78.0±9.0 kg; 7 females, height = 1.65±0.07m, mass = 68.3±9.4kg) volunteered and provided written informed consent. One HSC (Apple iPad Pro 9.7) filming at 240 Hz was placed at three standardized locations around the laboratory force plate. The HSC captured the point of ground contact on the force plate as subjects performed three running trials at different self-selected speeds (jog, run, sprint), with two minutes recovery between each trial. Velocity was measured with an automatic timing system (Free Lap), and GCT and VGRF were directly measured using an in-ground laboratory plate (Kistler 5691A) collecting at 1000 Hz. Video-based calculations of VGRF were based on GCT and equations of projectile motion. RESULTS: In comparison to the force plate, the HSC had a mean absolute error of 3.2%±2.2% (R2=0.97) for GCT and 10.7%±5.2% (R2=0.85) for VGRF. CONCLUSION: A commercially available HSC filming at 240 Hz can accurately determine GCT during over-ground running, but caution is warranted when using the proposed method to calculate VGRF.

Reference

Sabrina M. Mangeri, Tyler D. Whitacre, David J. Stearne, Kenneth P. Clark. Video Measures of Running Ground Contact Times and Vertical Ground Reaction Forces. Mid Atlantic Regional Chapter of the American College of Sports Medicine Annual Scientific Meeting, November 2-3, 2018 Conference Proceedings. International Journal of Exercise Science, Issue 9, Volume 7

Abstract: This study aimed to investigate the age‐related differences in sprinting performance, kinematic and kinetic variables in girls aged between 7.0 and 15.3 years. Step‐to‐step spatiotemporal variables and ground reaction impulses during sprinting were collected in 94 Japanese girls across a 50 m inground force plate system. From the results, a difference in rate of development in sprinting performance in girls over 12.7 years compared with younger girls (YG) was observed. The older girls (OG) became slightly slower each year (−0.09 m/s/y) compared to the YG (0.24 m/s/y) who increased their running speed. Moreover, height increased by 6.3 cm/y in YG and only 3.6 cm/y in OG, while step length during the maximal speed phase increased by 0.08 m/y in YG and plateaued in OG (0.01 m/y). Propulsive impulse during the initial acceleration phase was the kinetic variable to differ in rate of development between the age groups with an increase of 0.024 Ns/y in the YG compared to −0.010 Ns/y in OG. The development of sprinting ability in Japanese girls was more rapid before age 12.7 years. The difference in rate of development in sprinting ability can be primarily attributed to greater growth rates in YG, contributing to increases in the propulsive impulse during the initial acceleration phase and step length during the maximal speed phase. The limited gains in step length and the propulsive impulse in OG may reflect their reduced growth rate in height and the fact that increases in fat mass with maturation impaired relative force production.

Reference

Ryu Nagahara Miki Haramura Yohei Takai Jon L. Oliver 2019. Age‐related differences in kinematics and kinetics of sprinting in young females. Scandinavian Journal of Medicine & Science in Sports. January https://doi.org/10.1111/sms.13397

Abstract

Research to date has investigated the phenomenon of the bilateral deficit (BLD); however, limited research exists on its association with measures of athletic performance. The purpose of this study was to investigate the magnitude of the BLD and examine its relationship with linear speed and change of direction speed (CODS) performance. Eighteen physically active and healthy university students performed double- and single-leg countermovement jumps (CMJs), drop jumps (DJs), and standing broad jumps (SBJs) to calculate the BLD across jump tasks. Subjects also performed 10- and 30-m sprints and a 505 CODS test, which were correlated with all BLD metrics. Results showed varying levels of BLD across CMJ metrics (jump height, peak force, eccentric impulse, concentric impulse, and peak power), DJ metrics (ground contact time and flight time), and the SBJ (distance). However, a bilateral facilitation was shown for jump height and reactive strength index during the DJ test. The main findings of this study were that: (a) a larger BLD in CMJ height related to a faster 505 COD (left leg) (r = -0.48; p = 0.04), 505 COD (right leg) (r = -0.53; p = 0.02), and COD deficit (right leg) (r = -0.59; p = 0.01), (b) a larger BLD in CMJ concentric impulse related to faster 505 COD (left leg) (r = -0.51; p = 0.03), 505 COD (right leg) (r = -0.64, p = 0.01), and COD deficit (right leg) (r = -0.60; p = 0.01), and (c) a larger BLD in DJ flight time related to a faster 505 COD (left leg) (r = -0.48; p = 0.04). These results suggest that a larger BLD is associated with faster CODS performance, but not linear speed. This highlights the individual nature of the BLD and may support the notion of developing movement competency on one limb for enhanced CODS performance.

Bishop C1, Berney J1, Lake J2, Loturco I3, Blagrove R4, Turner A1, Read P5 . Bilateral Deficit During Jumping Tasks: Relationship With Speed and Change of Direction Speed Performance. Journal of Strength and Conditioning Research, 05 Feb 2019,

The purpose of the study was to examine the relationship between vertical stiffness, leg stiffness, and maximal sprint speed in a large cohort of 11–16-year-old boys. Three-hundred thirty-six boys undertook a 30-m sprint test using a floor-level optical measurement system, positioned in the final 15-m section. Measures of speed, step length, step frequency, contact time, and flight time were directly measured while force, displacement, vertical stiffness, and leg stiffness, were modeled from contact and flight times, from the 2 fastest consecutive steps for each participant over 2 trials. All force, displacement, and stiffness variables were significantly correlated with maximal sprint speed (p ≤ 0.05). Relative vertical stiffness had a very large (r > 0.7) relationship with sprint speed, whereas vertical center of mass displacement, absolute vertical stiffness, relative peak force, and maximal leg spring displacement had large (r > 0.5) relationships. Relative vertical stiffness and relative peak force did not significantly change with advancing age (p > 0.05), but together with maximal leg spring displacement accounted for 96% of the variance in maximal speed. It seems that relative vertical stiffness and relative peak force are important determinants of sprint speed in boys aged 11–16 years, but are qualities that may need to be trained because of no apparent increases from natural development. Practitioners may wish to use training modalities such as plyometrics and resistance training to enable adaptation to these qualities because of their importance as predictors of speed in youth.

Reference

Meyers, Robert W.1; Moeskops, Sylvia1; Oliver, Jon L.1,2; Hughes, Michael G.1; Cronin, John B.2,3; Lloyd, Rhodri S.1,2 Lower-Limb Stiffness and Maximal Sprint Speed in 11–16-Year-Old Boys. The Journal of Strength & Conditioning Research. July, Vol. 33, Issue 7.

Abstract

This study determined the horizontal to vertical force ratio (H:V) of two types of sprint starts and a variety of plyometric exercise, for the purpose of determining the exercises which are most biomechanically specific to sprinting. Subjects included 15 men. All subjects’ performed the sprinter start, the standing sprint start, the CMJ, 18 inch hurdle hop, bounding, power skipping, standing long jump, and multiple hops, starting on a force platform. A repeated measures ANOVA was used to determine differences in H:V between the sprinter start, the standing start, and the plyometric exercises. Results reveal significant main effects for sprint start H:V and standing start H:V, and the plyometric exercises H:V (p ≤ 0.001). Post-hoc analyses revealed that bounding and standing long jumps are the most biomechanically for training athletes for sprint starts.

Reference

Duffin, Garrett T., Stockero, Alyssa M., and Ebben, William P. 2019. The Optimal Plyometric Exercise Horizontal to Vertical Force Ratio for Sprinting.
International Society of Biomechanics in Sports. Vol. 37, 2019.