Inter-limb differences in unilateral countermovement jump height are not associated with the inter-limb differences in bilateral countermovement jump force production

2021 ◽  
pp. 1-13
Author(s):  
Sergio Miras-Moreno ◽  
Alejandro Pérez-Castilla ◽  
F. Javier Rojas ◽  
Danica Janicijevic ◽  
Juan Carlos De la Cruz ◽  
...  
Keyword(s):  
Force Production ◽  
Jump Height ◽  
Countermovement Jump

scholarly journals Position-specific countermovement jump characteristics of elite Women’s Rugby World Cup 2017 athletes

2021 ◽  
Author(s):  
Shane M. Heffernan ◽  
Ross Neville ◽  
Mark Waldron ◽  
Ryan Stewart ◽  
Liam P. Kilduff ◽  
...  
Keyword(s):  
Force Production ◽  
Rugby Union ◽  
Relative Power ◽  
Jump Height ◽  
Strength Index ◽  
Countermovement Jump ◽  
World Cup ◽  
Positional Variation ◽  
Scientific Attention

Rugby union (RU) is an intermittent team sport, with diverse playing positions, played internationally by both men and women. Considerable scientific attention has been devoted to men’s RU, however despite the growth in the women’s professional game, there is a significant lack of available physiological and normative data. The purpose of the present study was to investigate positional variation in countermovement jump characteristics from elite women’s RU players. Qualitative data were collected from women’s Rugby World Cup (2017) competitors (n = 86; age: 27 ± 5 years; body mass: 77.8 ± 10.6 kg; height: 1.69 ± 0.07 cm) and jump data (countermovement jumps) were collected using a 1200 Hz force platform (n = 63). Athletes were divided into positional unit (backs: n = 39 and forwards: n = 47) and by positional subgroups. Backs had greater jump height (ES = 0.72, 95%CL ± 0.50), relative power output (ES = 0.84, 95%CL ± 0.50), relative force production (ES = 0.62, 95%CL ± 0.51) and reactive strength index (RSI; ES = 0.62, 95%CL ± 0.50), compared to forwards (for all, P < 0.02). Backrows, halves and back-three players had greater relative force, relative power and jump height, compared to the front and second rows (P < 0.03; ES > 0.70). These data could aid in programming for long-term player development in women’s RU and could have implications for “readiness” to compete at international level.

Acute consumption of p-synephrine does not enhance performance in sprint athletes

2016 ◽  
Vol 41 (1) ◽  
pp. 63-69 ◽  
Author(s):  
Jorge Gutiérrez-Hellín ◽  
Juan José Salinero ◽  
Javier Abían-Vicen ◽  
Francisco Areces ◽  
Beatriz Lara ◽  
...  
Keyword(s):  
Scientific Information ◽  
Monitoring Program ◽  
Well Being ◽  
Placebo Control Trial ◽  
Placebo Control ◽  
Jump Height ◽  
Countermovement Jump ◽  
Squat Jump ◽  
Jump Test ◽  
The Hours

P-Synephrine is a protoalkaloid widely used as an ergogenic aid in sports. This substance has been included in the World Anti-Doping Agency monitoring program, although scientific information about its effects on performance and athletes’ well-being is scarce. The purpose of this investigation was to determine the effectiveness of p-synephrine to increase performance in sprint athletes. In a randomized and counterbalanced order, 13 experienced sprinters performed 2 acute experimental trials after the ingestion of p-synephrine (3 mg·kg−1) or after the ingestion of a placebo (control trial). Forty-five minutes after the ingestion of the substances, the sprinters performed a squat jump, a countermovement jump, a 15-s repeated jump test, and subsequently performed 60-m and 100-m simulated sprint competitions. Self-reported questionnaires were used to assess side-effect prevalence. In comparison with the control trial, the ingestion of p-synephrine did not change countermovement jump height (37.4 ± 4.2 vs 36.7 ± 3.3 cm, respectively; P = 0.52), squat jump height (34.4 ± 3.6 vs 33.9 ± 3.7 cm; P = 0.34), or average 15-s repeated jumps height (31.8 ± 4.1 vs 32.2 ± 3.6 cm; P = 0.18). P-Synephrine did not modify maximal running speed during the 60-m (9.0 ± 0.5 vs 9.0 ± 0.4 m·s−1, respectively; P = 0.55) and 100-m sprint competitions (8.8 ± 0.5 vs 8.8 ± 0.5 m·s−1, respectively; P = 0.92). The ingestion of p-synephrine did not alter the prevalence of headache, gastrointestinal discomforts, muscle pain, or insomnia during the hours following the tests. Acute consumption of 3 mg·kg−1 of p-synephrine was ineffective to increase performance in competitive sprint athletes. Moreover, p-synephrine did not increase the occurrence of side effects after the competition.

Roller Massage Prior to Running Does Not Affect Gait Mechanics in Well-Trained Runners

2021 ◽  
pp. 1-9
Author(s):  
Jessica G. Hunter ◽  
Gina L. Garcia ◽  
Sushant M. Ranadive ◽  
Jae Kun Shim ◽  
Ross H. Miller
Keyword(s):  
Repeated Measures ◽  
Reaction Force ◽  
Force Production ◽  
Endurance Athletes ◽  
Jump Height ◽  
Jump Performance ◽  
Average Load ◽  
Load Rate ◽  
Free Moment ◽  
Muscle Force Production

Context: Understanding if roller massage prior to a run can mitigate fatigue-related decrements in muscle force production during prolonged running is important because of the association between fatigue and running-related injury. Objective: The authors investigated whether a bout of roller massage prior to running would (1) mitigate fatigue-related increases in vertical average load rate and free moment of the ground reaction force of running and (2) mitigate decreases in maximal countermovement jump height. Design: Repeated-measures study. Setting: Laboratory. Participants: A total of 14 recreational endurance athletes (11 men and 3 women) volunteered for the study. Interventions: A 12.5-minute foam roller protocol for the lower extremities and a fatiguing 30-minute treadmill run. Main Outcome Measures: Vertical average load rate, free moment, and maximal jump height before (PRE) and after (POST) the fatiguing treadmill run on separate experimental days: once where participants sat quietly prior to the fatiguing run (REST) and another where the foam roller protocol was performed prior to the run (ROLL). Results: A 2-way multiple analysis of variance found no significant differences in vertical average load rate, free moment, and jump height between PRE/POST times in both REST/ROLL conditions. Conclusions: The authors concluded that recreational endurance athletes maintain running mechanics and jump performance after a fatiguing run regardless of prerun roller massage and may not rely on prerun roller massage as a form of injury prevention.

scholarly journals The Protective Effect of Neuromuscular Training on the Medial Tibial Stress Syndrome in Youth Female Track-and-Field Athletes: A Clinical Trial and Cohort Study

2021 ◽  
pp. 1-9
Author(s):  
Guillermo Mendez-Rebolledo ◽  
Romina Figueroa-Ureta ◽  
Fernanda Moya-Mura ◽  
Eduardo Guzmán-Muñoz ◽  
Rodrigo Ramirez-Campillo ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Relative Risk ◽  
Confidence Interval ◽  
Lower Limb ◽  
Track And Field ◽  
Medial Tibial Stress Syndrome ◽  
Injury Incidence ◽  
Jump Height ◽  
Countermovement Jump ◽  
Stress Syndrome

Context: Few reports have analyzed the effects of neuromuscular (NM) training programs on the injury incidence among youth female track-and-field athletes. Objective: To determine the effects of NM training on reducing lower limb injury incidence and to establish its effects on countermovement jump performance, balance, 30-m sprint, and joint position sense in youth female track-and-field athletes. Design: Single-blind, randomized controlled clinical trial. Setting: Sports research laboratory. Participants: Twenty-two female athletes were allocated into 2 groups: Conventional (CONV) training (n = 11; age = 15.3 [2.1] y) and NM training (n = 11; age = 15.0 [2.7] y). Interventions: Interventions were performed during the preseason of 6 weeks. The CONV training included anaerobic, strength, and aerobic training. The NM training consisted of a multicomponent program that integrated jumps, landings, and running with strength, endurance, agility, balance, and CORE training. Main Outcome Measures: A follow-up of the cohorts was carried out through the evaluation of lower limb injuries (main outcome) during a regular season (weeks 7–18). Secondary outcomes were measured before and after the intervention: Y-balance test, active joint repositioning, ground reaction force, and countermovement jump height. Results: The injury incidence rate was 17.89 injuries per 1000 hours athlete-exposure in CONV training, and 6.58 in NM training (relative risk = 0.38; 95% confidence interval,  0.18 to 0.82; P = .044). Particularly, the medial tibial stress syndrome incidence rate was 5.96 injuries per 1000 hours athlete-exposure in CONV training and 0.82 in NM training (relative risk = 0.17; 95% confidence interval, 0.02 to 1.12; P = .012). In addition, a significant training × time interaction was noted, favoring improvements in 30-m sprint and countermovement jump height after NM. Conclusion: The NM training may improve youth female athlete’s physical fitness and reduce their injury relative risk of medial tibial stress syndrome injury.

A Comparison of Different Modes of Morning Priming Exercise on Afternoon Performance

2016 ◽  
Vol 11 (6) ◽  
pp. 763-767 ◽  
Author(s):  
Mark Russell ◽  
Aden King ◽  
Richard. M. Bracken ◽  
Christian. J. Cook ◽  
Thibault Giroud ◽  
...  
Keyword(s):  
Reaction Time ◽  
Rugby Union ◽  
Jump Height ◽  
Countermovement Jump ◽  
Repeated Sprint ◽  
Mass Load ◽  
Hormone Responses ◽  
Sprint Cycling ◽  
Priming Exercise ◽  
Rugby Players

Purpose:To assess the effects of different modes of morning (AM) exercise on afternoon (PM) performance and salivary hormone responses in professional rugby union players.Methods:On 4 occasions (randomized, crossover design), 15 professional rugby players provided AM (~8 AM) and PM (~2 PM) saliva samples before PM assessments of countermovement-jump height, reaction time, and repeated-sprint ability. Control (passive rest), weights (bench press: 5 × 10 repetitions, 75% 1-repetition maximum, 90-s intraset recovery), cycling (6 × 6-s maximal sprint cycling, 7.5% body mass load, 54-s intraset recovery), and running (6 × 40-m maximal sprints, 20-s intraset recovery) interventions preceded (~5 h) PM testing.Results:PM sprint performance improved (P < .05) after weights (>0.15 ± 0.19 s, >2.04% ± 2.46%) and running (>0.15 ± 0.17 s, >2.12% ± 2.22%) but not cycling (P > .05). PM jump height increased after cycling (0.012 ± 0.009 m, 2.31% ± 1.76%, P < .001) and running (0.020 ± 0.009 m, 3.90% ± 1.79%, P < .001) but not weights (P = .936). Reaction time remained unchanged between trials (P = .379). Relative to control (131 ± 21 pg/mL), PM testosterone was greater in weights (21 ± 23 pg/mL, 17% ± 18%, P = .002) and running (28 ± 26 pg/mL, 22% ± 20%, P = .001) but not cycling (P = .072). Salivary cortisol was unaffected by AM exercise (P = .540).Conclusions:All modes of AM exercise improved at least 1 marker of PM performance, but running appeared the most beneficial to professional rugby union players. A rationale therefore exists for preceding PM competition with AM exercise.

Effects of Collagen Peptides on Recovery Following Eccentric Exercise in Resistance-Trained Males—A Pilot Study

2020 ◽  
pp. 1-8
Author(s):  
Joel L. Prowting ◽  
Debra Bemben ◽  
Christopher D. Black ◽  
Eric A. Day ◽  
Jason A. Campbell
Keyword(s):  
Muscle Soreness ◽  
Exercise Bout ◽  
Jump Height ◽  
Countermovement Jump ◽  
Connective Tissues ◽  
Maximal Voluntary Isometric Contraction ◽  
Collagen Peptides ◽  
Drop Jumps ◽  
Performance Decline ◽  
Time Point

The authors sought to determine whether consuming collagen peptides (CP) enhances musculoskeletal recovery of connective tissues following a damaging exercise bout. Resistance-trained males consumed 15 g/day of CP (n = 7) or placebo (n = 8), and after 7 days, maximal voluntary isometric contraction (MVIC), countermovement jump height, soreness, and collagen turnover were examined. Five sets of 20 drop jumps were performed and outcome measures were collected 24, 48, and 120 hr postexercise. Countermovement jump height was maintained in the CP group at 24 hr (PRE = 39.9 ± 8.8 cm vs. 24 hr = 37.9 ± 8.9 cm, p = .102), whereas the CP group experienced a significant decline at 24 hr (PRE = 40.4 ± 7.9 cm vs. 24 hr = 35.5 ± 6.4 cm, p = .001; d = 0.32). In both groups, muscle soreness was significantly higher than PRE at 24 hr (p = .001) and 48 hr (p = .018) but not at 120 hr (p > .05). MVIC in both legs showed a significant time effect (left: p = .007; right: p = .010) over the 5-day postexercise period. Neither collagen biomarker changed significantly at any time point. CP supplementation attenuated performance decline 24 hr following muscle damage. Acute consumption of CP may provide a performance benefit the day following a bout of damaging exercise in resistance-trained males.

Why is countermovement jump height greater than squat jump height?

1996 ◽  
Vol 28 (11) ◽  
pp. 1402-1412 ◽  
Author(s):  
MAARTEN F. BOBBERT ◽  
KARIN G. M. GERRITSEN ◽  
MARIA C. A. LITJENS ◽  
ARTHUR J. VAN SOEST
Keyword(s):  
Jump Height ◽  
Countermovement Jump ◽  
Squat Jump

scholarly journals Efectos de entrenamiento de fuerza en sistema isoinercial sobre la mejora del CMJ en jóvenes futbolistas de elite (Effects of strength training using a isoinertial device on jump ability in young elite soccer players)

Retos ◽  
2015 ◽  
pp. 180-182
Author(s):  
Sergio Romero Boza ◽  
Adrián Feria Madueño ◽  
Borja Sañudo Corrales ◽  
Moisés De Hoyo Lora ◽  
Juan José Del Ojo López
Keyword(s):  
Strength Training ◽  
Force Production ◽  
Team Sport ◽  
Soccer Players ◽  
Maximal Strength ◽  
Countermovement Jump ◽  
Palabras Clave ◽  
Jump Ability ◽  
Physical Skills

El fútbol es un deporte colectivo donde, para alcanzar el éxito, los jugadores necesitan de habilidades técnicas, tácticas y físicas, fundamentalmente de carácter intermitente siendo éstas acciones las que determinan el rendimiento. Un ejemplo de acciones de este tipo son los saltos. Este gesto deportivo esta correlacionado con la fuerza máxima, entendiendo que una mayor producción de fuerza permite una mayor generación de altura en dicho gesto. El objetivo de este trabajo es estudiar el efecto de entrenamiento de fuerza en sistema isoinercial sobre la mejora del Salto con Contramovimiento y analizar los cambios en la altura del mismo después de un programa de entrenamiento de 15 semanas, realizado sobre jóvenes futbolistas de élite. Los resultados obtenidos, muestran que no existen cambios significativos en esta variable de análisis (p< 0,05) por lo que se concluye que este tipo de entrenamiento con la duración especificada no tiene efectos sobre el rendimiento en la altura del salto (CMJ).Palabras clave: Entrenamiento Isoinercial, Futbolistas, Rendimiento, CMJ.Abstract: Soccer is a team sport where, to achieve success, players need of technical, tactical and physical skills, mainly intermittent character being such actions which determine the performance. An example of such actions is the jumpers. This sports actions is correlated with the maximal strength, understanding that force production allows greater height in this actions. The aim is to study the effects of strength training using a isoinertial device on Countermovement Jump ability and to analyze the changes in height after 15 weeks program training in young elite soccer players. There are no significant changes after to analyze the results (p< 0,05), so it is concluded that this type of training with certified duration has no effect on performance in height jump (CMJ).Keywords: Isoinertial Training, Soccers Players, Performance, CMJ.

scholarly journals The Influence of Recruitment Age and Anthropometric and Physical Characteristics on the Development Pathway of English Academy Football Players

2020 ◽  
pp. 1-9
Author(s):  
Mark R. Noon ◽  
Emma L.J. Eyre ◽  
Matthew Ellis ◽  
Tony D. Myers ◽  
Rhys O. Morris ◽  
...  
Keyword(s):  
Cross Sectional Study ◽  
Physical Characteristics ◽  
Bayesian Regression ◽  
Football Players ◽  
Jump Height ◽  
Countermovement Jump ◽  
Cross Sectional ◽  
Male Youth ◽  
Development Pathway ◽  
Key Indicator

Purpose: To investigate the influence of recruitment age on retention and release across the development pathway and to explore the influence of anthropometric and physical characteristics on retention and release at different ages throughout the development pathway and the likelihood of obtaining a professional contract. Methods: Following receipt of ethics approval, a cross-sectional study tracking 4 cohorts of players over 5 years assessed 76 male youth football players (11–16 y) from an English football academy on 3 occasions annually in anthropometry, countermovement jump height, and linear (30 and 15 m) and multidirectional sprint time. Players were categorized based on their start and release date. Results: Starting early (ie, before U12) in an academy was a key indicator of obtaining a professional contract, representing 87% of the players signed. Bayesian regression models suggest that the majority of differences in physical characteristics between players that were released and retained are trivial, small, and/or uncertain. Players who attained a professional contract at 18 had slower 15- and 30-m sprint times at U13 to U15 (P > 0 = .87–.99), slower multidirectional sprint times at U14 (P > 0 = .99), and lower countermovement jump height at U13 to U16 (P > 0 = .88–.99) compared with players who did not gain a contract. Conclusion: Players recruited early have an increased likelihood of gaining a professional contract. Physical assessments lack utility when used in isolation as a talent-identification tool.

scholarly journals Factors of influence on performance of countermovement jump

2020 ◽  
Vol 10 (2) ◽  
pp. 33-46
Author(s):  
Dragan Klisarić ◽  
Milan Matić
Keyword(s):  
Body Composition ◽  
Muscle Power ◽  
External Factors ◽  
Jump Height ◽  
Countermovement Jump ◽  
Internal Factors ◽  
Training Performance ◽  
Performance Technique ◽  
Stretch Shortening Cycle ◽  
Composition Factors

Countermovement jump is an exercise that develops leg muscle power, the efficiency of using the stretch-shortening cycle, and the jump height. Numerous factors influence countermovement jump height. This paper analyses the most important external and internal factors. The aim of this paper was to describe and explain the influence of external factors on countermovement jump height. A comparative analytical method is used to compare and comment on the results of scientific research. The following external factors are considered in this paper: type of training, performance technique, and instructions, and internal factors: age, sex, body composition. The results of the paper showed that among external factors, the greatest influence is noted in the performance technique factor, while among internal factors there is a contingent influence of age, sex, and body composition factors on countermovement jump height. The results of the paper contribute to the understanding of the nature of the influence of external and internal factors that affect countermovement jump height, which can improve scientific - professional work in sports.

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