Browse

You are looking at 41 - 50 of 264 items for :

  • Sport and Exercise Science/Kinesiology x
  • International Journal of Sports Physiology and Performance x
  • Refine by Access: Content accessible to me x
Clear All
Free access

The Physical Preparation of Players for the Rugby World Cup

David B. Pyne, Christian J. Cook, and Liam P. Kilduff

Free access

Erratum. Hematological Adaptations Following a Training Camp in Hot and/or Hypoxic Conditions in Elite Rugby Union Players

International Journal of Sports Physiology and Performance

Free access

Competitive Cross-Country Skiers Have Longer Time to Exhaustion Than Recreational Cross-Country Skiers During Intermittent Work Intervals Normalized to Their Maximal Aerobic Power

Eivind Holsbrekken, Øyvind Gløersen, Magne Lund-Hansen, and Thomas Losnegard

Purpose: To investigate differences in time to exhaustion (TTE), O2 uptake ( V ˙ O 2 ), and accumulated O2 deficit ( O 2 def ) between competitive and recreational cross-country (XC) skiers during an intermittent-interval protocol standardized for maximal aerobic power (MAP). Methods: Twelve competitive (maximal V ˙ O 2 [ V ˙ O 2 max ] = 76.5 ± 3.8 mL · kg 1 · min 1 ) and 10 recreational ( V ˙ O 2 max = 63.5 ± 6.3 mL · kg 1 · min 1 ) male XC skiers participated. All tests were performed on a rollerski treadmill in the V2 ski-skating technique. To quantify MAP and maximal accumulated oxygen deficit (MAOD), the skiers performed a steady-state submaximal test followed by a 1000-m time trial. After a 60-minute break, TTE, V ˙ O 2 , and accumulated O 2 def were measured during an intermittent-interval protocol (40-s work and 20-s recovery), which was individually tailored to 120% and 60% of each subject’s MAP. Results: During the 1000-m time trial, the competitive skiers had 21% (95% CI, 12%–30%) shorter finish time and 24% (95% CI, 14%–34%) higher MAP (all P < .01) than the recreational skiers. No difference was observed in relative exercise intensity (average power/MAP; P = .28), MAOD (P = .18), or fractional utilization of V ˙ O 2 max . During the intermittent-interval protocol, the competitive skiers had 34% (95% CI, 3%–65%) longer TTE (P = .03) and accumulated 61% (95% CI, 27%–95%) more O 2 def (P = .001) than the recreational skiers during work phases. Conclusions: Competitive XC skiers have longer TTE and accumulate more O 2 def than recreational XC skiers during an intermittent-interval protocol at similar intensity relative to MAP. This implies that performance in intermittent endurance sports is related to the ability to repeatedly recharge fractions of MAOD.

Free access

A Systematic Review on the Physical, Physiological, Perceptual, and Technical–Tactical Demands of Official 3 × 3 Basketball Games

Pierpaolo Sansone, Daniele Conte, Antonio Tessitore, Ermanno Rampinini, and Davide Ferioli

Purpose: To systematically review the physical, physiological, perceptual, and technical–tactical demands of official 3 × 3 basketball games. Methods: The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed. Three electronic databases (PubMed, Scopus, and Web of Science) were systematically searched to identify studies assessing physical, physiological, perceptual, and technical–tactical demands of 3 × 3 games. Data were also coded according to player sex and tournament phase. Quality assessment of the included studies was performed using a modified Downs and Black checklist. Results: Thirteen articles were finally included, with a mean quality of 8.6 (1.1) out of 11. Three-by-three basketball games have an intermittent profile (1:1 work–rest ratio), with a duration of ∼15 minutes, and are characterized by short (6–8 s) ball possessions and considerable physical (17–33 accelerations, 24–44 decelerations, 62–94 changes of directions, and 17–24 jumps per game) and physiological (lactate: ∼6.2 mmol·L−1) demands. Overall, the game performance profile is similar in males and females, with minor changes happening across tournament phases. Several key technical–tactical indicators were identified as discriminating winning and losing teams, such as better shooting and defensive efficiency, low number of turnovers, and implementing tactical actions involving more players, passing first, and ending possessions with shots from outside of the arch from the top of the key. Conclusions: Three-by-three basketball is an intermittent, physically demanding sport characterized by quick plays and specific tactical constraints. This review provides information that should be considered by performance staff to improve training prescription, game tactical plans, and for player selection and talent identification.

Free access

The 2-Point Method: Theoretical Basis, Methodological Considerations, Experimental Support, and Its Application Under Field Conditions

Amador García-Ramos

The “2-point method,” originally referred to as the “2-load method,” was proposed in 2016 by Prof Slobodan Jaric to characterize the maximal mechanical capacities of the muscles to produce force, velocity, and power. Two years later, in 2018, Prof Jaric and I summarized in a review article the scientific evidence showing that the 2-point method, compared with the multiple-point method, is capable of providing the outcomes of the force–velocity (F–V) and load–velocity (L–V) relationships with similar reliability and high concurrent validity. However, a major gap of our review was that, until 2018, the feasibility of the 2-point method had only been explored through testing procedures based on multiple (more than 2) loads. This is problematic because (1) it has misled users into thinking that implementing the 2-point method inevitably requires testing more than 2 conditions and (2) obtaining the data from the same test could have artificially inflated the concurrent validity of the 2-point method. To overcome these limitations, subsequent studies have implemented in separate sessions the 2-point method under field conditions (only 2 different loads applied in the testing protocol) and the standard multiple-point method. These studies consistently demonstrate that while the outcomes of the 2-point method exhibit comparable reliability, they tend to have slightly higher magnitudes compared with the standard multiple-point method. This review article emphasizes the practical aspects that should be considered when applying the 2-point method under field conditions to obtain the main outcomes of the F–V and L–V relationships.

Free access

Academic Freedom? Not in the United States (at Least at the Mayo Clinic)

Carl Foster

Open access

Rugby Players Exhibit Stiffer Biceps Femoris, Lower Biceps Femoris Fascicle Length to Knee Extensors, and Knee Flexors to Extensors Muscle Volume Ratios Than Active Controls

Gokhan Yagiz, Nami Shida, Hironobu Kuruma, Masahiro Furuta, Koji Morimoto, Mutsuo Yamada, Tatsuji Uchiyama, Hans-Peter Kubis, and Julian A. Owen

Purpose: This study aimed to determine if hamstring-strain-injury risk factors related to muscle structure and morphology differed between rugby union players and controls. Methods: The biceps femoris long head (BFlh) fascicle length and passive muscle stiffness and relative and absolute muscle volume of knee flexors (KF) and extensors (KE) were measured in 21 male subelite rugby players and 21 male physically active nonathletes. Results: BFlh fascicle length was significantly longer (mean difference [MD] = 1.6 [1.7] cm) and BFlh passive muscle stiffness was significantly higher in rugby players (MD = 7.8 [14.8] kPa). The absolute BFlh (MD = 71.9 [73.3] cm3), KF (MD = 332.3 [337.2] cm3), and KE (MD = 956.3 [557.4] cm3) muscle volumes were also significantly higher in rugby players. There were no significant differences in the relative BFlh and KF muscle volumes. The relative KE muscle volumes were significantly higher in rugby players (MD = 2.3 [3.7] cm3/kg). However, the percentage BFlh fascicle length:KE (MD = −0.1% [0.1%]), BFlh/KE (MD = −0.9% [1.9%]), and KF:KE (MD = −4.9% [5.9%]) muscle volume ratios were significantly lower in the rugby players. BFlh muscle volume significantly correlated with BFlh fascicle length (r = .59, r 2 = .35) and passive muscle stiffness (r = .46, r 2 = .21). Conclusion: Future prospective studies should examine whether there are threshold values in BFlh passive muscle stiffness and BFlh fascicle length:KE, BFlh:KE, and KF:KE muscle volume ratios for predicting hamstring strain injuries.

Free access

Training and Competition Loads in Women’s Rugby Sevens Athletes: Are There Implications for Cardiovascular Health?

Luca Napoli, Stuart Semple, and Andrew J. McKune

National- and international-level rugby sevens athletes are exposed to high training and competition loads over the course of a competitive season. Research on load monitoring and body-system responses is widespread; however, the primary focus has been on optimizing performance rather than investigating or improving cardiovascular health. There is a degree of cardiovascular remodeling, as well as local and systemic inflammation, in response to excessive exercise. These responses are moderated by many factors including previous exercise exposure, current exercise intensity and duration, age, race, and gender, as well as sport-specific physiology. For these reasons, high-performing female rugby sevens athletes may have a unique cardiovascular risk profile different from males and other rugby codes. This review aimed to characterize the training and competition loads, as well as the anthropometric and physiological profiles, of female rugby sevens athletes; discuss the potential impacts these may have on the cardiovascular system; and provide recommendations on future research regarding the relationship between rugby sevens training and competition loads and cardiovascular health. Movement demands, competition formatting, and training routines could all contribute to adverse cardiovascular adaptations. Anthropometric data and physiological characteristics may also increase the risk of cardiovascular disease. Future research needs to adopt measures of cardiovascular health to obtain a greater understanding of cardiovascular profiles and risk factors in female rugby sevens athletes.

Open access

Synthetic Data as a Strategy to Resolve Data Privacy and Confidentiality Concerns in the Sport Sciences: Practical Examples and an R Shiny Application

Mitchell Naughton, Dan Weaving, Tannath Scott, and Heidi Compton

Purpose: There has been a proliferation in technologies in the sport performance environment that collect increasingly larger quantities of athlete data. These data have the potential to be personal, sensitive, and revealing and raise privacy and confidentiality concerns. A solution may be the use of synthetic data, which mimic the properties of the original data. The aim of this study was to provide examples of synthetic data generation to demonstrate its practical use and to deploy a freely available web-based R Shiny application to generate synthetic data. Methods: Openly available data from 2 previously published studies were obtained, representing typical data sets of (1) field- and gym-based team-sport external and internal load during a preseason period (n = 28) and (2) performance and subjective changes from before to after the posttraining intervention (n = 22). Synthetic data were generated using the synthpop package in R Studio software, and comparisons between the original and synthetic data sets were made through Welch t tests and the distributional similarity standardized propensity mean squared error statistic. Results: There were no significant differences between the original and more synthetic data sets across all variables examined in both data sets (P > .05). Further, there was distributional similarity (ie, low standardized propensity mean squared error) between the original observed and synthetic data sets. Conclusions: These findings highlight the potential use of synthetic data as a practical solution to privacy and confidentiality issues. Synthetic data can unlock previously inaccessible data sets for exploratory analysis and facilitate multiteam or multicenter collaborations. Interested sport scientists, practitioners, and researchers should consider utilizing the shiny web application (SYNTHETIC DATA—available at https://assetlab.shinyapps.io/SyntheticData/).

Free access

Adapting Training to the Menstrual Cycle

Xanne A.K. Janse de Jonge and Belinda M. Thompson