Yo-Yo IRT Research Articles

Examining the Relationship Between Yo-Yo Intermittent Rest Test Results and Performance in Football Players

The purpose of your study; The aim is to determine the relationship between aerobic endurance and the performance of football players. 30 licensed football players (age 18,33±0,47 years, height 179,5±10,6 cm, body weight 76,6±11,5 kg) playing in the Turkish Football Federation U-19 Development League voluntarily participated in the research. Football players' Yo-Yo IRT1 test was measured twice at eight-week intervals on an artificial football field. During the test, Heart rate (HR) (beats/min) and afterwards Maximal Aerobic Power (VO2max) values were measured and calculated. Paried T-test, one of the parametric tests, was used to determine whether there was a difference in terms of Yo-Yo IRT 1 test, VO2max values and pulse values. All analyzes were processed at the 0.05 significance level. In conclusion; There is no statistically significant difference p>0.005 between the first and last values of the distances traveled by the football players who were subjected to the Yo-Yo IR1 test first and last measurement test, their HR and their measured VO2max values.

The relationships between ACTN3 rs1815739 and PPARA-α rs4253778 gene polymorphisms and athletic performance characteristics in professional soccer players

BackgroundCurrent research on athletic performance focuses on genetic variants that contribute significantly to individuals’ performance. ACTN3 rs1815739 and PPARA-α rs4253778 gene polymorphisms are variants frequently associated with athletic performance among different populations. However, there is limited research examining the pre-and post-test results of some variants of athletic performance in soccer players. Therefore, the presented research is to examine the relationships between the ACTN3 rs1815739 and PPARA-α rs4253778 gene polymorphisms and athletic performance improvement rates in adaptations to six weeks of training in elite soccer players using some athletic performance tests.MethodologyTwenty-two soccer players between the ages of 18 and 35 voluntarily participated in the study. All participants were actively engaged in a rigorous six-day-a-week training program during the pre-season preparation period. Preceding and following the training program, a battery of diverse athletic performance tests was administered to the participants. Moreover, Genomic DNA was extracted from oral epithelial cells using the Invitrogen DNA isolation kit (Invitrogen, USA), following the manufacturer’s protocol. Genotyping was conducted using real-time PCR. To assess the pre- and post-test performance differences of soccer players, the Wilcoxon Signed Rank test was employed.ResultsUpon analyzing the results of the soccer players based on the ACTN3 genotype variable, it was observed that there were no statistically significant differences in the SJ (Squat Jump), 30m sprint, CMJ (Counter Movement Jump), and DJ (Drop Jump) performance tests (p > 0.05). However, a statistically significant difference was identified in the YOYO IRT 2 (Yo-Yo Intermittent Recovery Test Level 2) and 1RM (One Repetition Maximum) test outcomes (YOYO IRT 2: CC, CT, and TT, p = 0.028, 0.028, 0.008, 0.000, respectively; 1RM: CC, CT, and TT, p = 0.010, 0.34, 0.001, respectively). Regarding the PPARA-α genotype variable, the statistical analysis revealed no significant differences in the SJ, 30m sprint, CMJ, and DJ performance tests (p > 0.05). Nevertheless, a statistically significant difference was observed in the YOYO IRT 2 and 1RM test results (YOYO IRT 2: CC, CG p = 0.001, 0.020; 1RM: CC, p = 0.000)ConclusionsThe current study demonstrated significant enhancements in only YOYO INT 2 and 1RM test outcomes across nearly all gene variants following the six-day-a-week training program. Other performance tests, such as the 30m sprint, SJ, CMJ, and DJ tests did not exhibit statistically significant differences. These findings contribute novel insights into the molecular processes involving PPARA-α rs4253778 and ACTN3 rs1815739 that underpin enhancements in endurance (YOYO INT 2) and maximal strength (1RM) aspects of athletic performance. However, to comprehensively elucidate the mechanisms responsible for the association between these polymorphisms and athletic performance, further investigations are warranted. It is thought that the use of field and genetic analyses together to support each other will be an important detail for athletes to reach high performance.

Association of ACTN3 R577X Polymorphism with Elite Basketball Player Status and Training Responses.

The α-actinin-3 (ACTN3) gene rs1815739 (C/T, R577X) polymorphism is a variant frequently associated with athletic performance among different populations. However, there is limited research on the impact of this variant on athlete status and physical performance in basketball players. Therefore, the aim of this study was twofold: (1) to determine the association of ACTN3 rs1815739 polymorphism with changes in physical performance in response to six weeks of training in elite basketball players using 30 m sprint and Yo-Yo Intermittent Recovery Test Level 2 (IR 2) tests, and (2) to compare ACTN3 genotype and allelic frequencies between elite basketball players and controls. The study included a total of 363 individuals, comprising 101 elite basketball players and 262 sedentary individuals. Genomic DNA was isolated from oral epithelial cells or leukocytes, and genotyping was performed by real-time PCR using KASP genotyping method or by microarray analysis. We found that the frequency of the ACTN3 rs1815739 XX genotype was significantly lower in basketball players compared to controls (10.9 vs. 21.4%, p = 0.023), suggesting that RR/RX genotypes were more favorable for playing basketball. Statistically significant (p = 0.045) changes were observed in Yo-Yo IRT 2 performance measurement tests in basketball players with the RR genotype only. In conclusion, our findings suggest that the carriage of the ACTN3 rs1815739 R allele may confer an advantage in basketball.

The 3-Minute Burpee Test: A Minimalistic Alternative to the Conventional Estimated Oxygen Uptake Test.

Background Maximal oxygen uptake and muscle strength are fundamental components of physical fitness. Improving these capacities is highly beneficial to health. The validity of maximal oxygen uptake and muscle strength has been widely emphasized in clinical, sports, and research-related settings. However, many of the previous tests required special equipment and space. Aim This study examined the effectiveness of field tests that do not require special equipment or space. Materials and methods The relationship between the 3-minute burpee test (3MBT) and estimated maximal oxygen uptake (Yo-Yo intermittent recovery test (Yo-Yo IRT)) using whole-body muscle groups was examined.The subjects were young men (n=127) with a history of exercising at least once a week. Results A strong relationship between 3MBT and Yo-YoIRT was shown (p<0.001). Conclusions The 3MBT is a field test that can be performed anytime and anywhere there is space for plank and standing postures. Because it is very brief, efficient, and uses muscle groups throughout the body, it is effective and potentially quite useful as a new field test.

An analysis of the relationship between critical velocity and anaerobic speed reserve with match running profile in football

Background and Study Aim. The aim of this study was to analyse the relationship between critical velocity (CV) and anaerobic speed reserve (ASR) with match running profile in football.&#x0D; Material and Methods. The research group consisted of fifteen young male football players (n=15, age=16.60±0.51 years, height=177.40±5.25 cm, weight=67.20±5.52 kg, body mass index=21.32±0.96 kg/m2). Yo-Yo intermittent recovery level 1 test (Yo-Yo IRT) was performed to determine maximal aerobic speed (MAS). Maximal sprint speed (MSS) was determined by 30-meter sprint test. CV and ADC parameters were obtained by linear regression model (Lin-TD: linear total distance model) between the covered distance and running duration in 800-meter and 2400-meter running tests. A 90-minutes football match was played to determine the subjects’ match running profile (covered distance in every running category), which was examined by means of a global positioning system (GPS) device in five running categories (walking: 0-6.9 km/h, low intensity running: 7-12.9 km/h, middle intensity running: 13-17.9 km/h, high intensity running: 18-20.9 km/h, sprint: &gt;21 km/h). Correlation analysis and multiple linear regression analysis was employed to analyse the collected data.&#x0D; Results. It was found that CV was significantly and positively correlated with total running distance as well as low and middle intensity running (p&lt;0.05). A significant and negative correlation was found between ASR and all match running profiles (p&lt;0.05). Both CV and ASR were significant predictors of high intensity running, maximum running speed and total running distance during match (p&lt;0.05). However, while CV was a significant predictor of sprint running, ASR significantly predicted walking (p&lt;0.05).&#x0D; Conclusions. Consequently, it may be concluded that in football, aerobic fitness is positively correlated to CV and negatively to ASR.

Influence of Upper and Lower Body Anthropometric Measures on An Aggregate Physical Performance Score in Young Elite Male Soccer Players: A Case Study

Background: The present study aimed to determine the association of anthropometry-based characteristics with an aggregate score (AS) of physical performance in young elite soccer players. Methods: Sixteen under 15 elite players were enrolled. Among numerous anthropometrics variables, upper arm contracted (UACC) and relaxed circumference (UARC), corrected arm muscle area (AMAcorr), arm muscle circumference (AMC), thigh muscle circumference (TMC) and suprapatellar girths were also employed in this study. Players’ physical performance was assessed by the change of direction (COD), 10 m and 20 m sprint, countermovement jump (CMJ) test, sprint with 90∘ turns (with ball), and yo-yo intermittent recovery test level 1 (Yo-Yo IRT1). The AS was computed by Principal Components Analysis technique with one component on normalized performance results. A stepwise regression analysis was conducted to assess potential association between anthropometry-based variables and AS. Results: Large negative correlations (r &lt; –0.68) of AS with UACC, UARC, AMAcorr, and AMC were detected. UACC and TMC permits to accurately estimate AS explaining 60% of the total variance (p &lt; 0.001). Conclusions: These findings demonstrated the importance of including anthropometry-based measures of both upper and lower body to the physical performance potential expressed by AS in elite youth soccer.

The Effect of High Intensity Interval Training on Agility Performance

Background and Study Aim: The aim of the study was to investigate the effects of high intensity interval training (HIIT) on agility performances of male football and volleyball players in university teams. Material and Methods: 10 non-elite male football players (mean age 21.17 ± 0.70 years, mean height 176.88 ± 4.86 cm, and mean weight 79.12 ± 8.31 kg) and 10 non-elite male volleyball players (mean age 20.84 ± 1.54 years, mean height 185.41 ± 8.31 cm, and mean weight 78.93 ± 8.85 kg) volunteered for the study. The participants performed HIIT (30 sec exercise/30 sec rest) twice a week for four weeks. Agility T test was performed with the participants before and after the training. Results: There found no statistical difference (p&gt;0.05) in terms of the agility performance values of the male football and volleyball players before and after the training. The pre and post training measurements after Yo-Yo IRT 1 showed that while the group with the football players did not recover in their agility performances up to 48 hours, the volleyball players were able to recover 48 hours after the training. Conclusion: It was found out that HIIT practises had no effect on improving agility time; however, it was effective in recovery of agility time post Yo-Yo IRT 1. Keywords: football, volleyball, agility, high intensity interval training

Absolute and relative reliability of SCRuM test battery components assembled for schoolboy rugby players playing competitive rugby in low-resource settings: A pragmatic in-season test-retest approach.

Schoolboy rugby is a popular sport which forms the bedrock of rugby development in many African countries, including Zimbabwe. With burgeoning talent identification programmes, the development of multi-dimensional, logically-validated, and reliable test batteries is essential to inform the objective selection of potentially talented young rugby athletes. This study sought evidence on the absolute and relative test-retest reliability of the component test items in the newly-assembled SCRuM test battery. Utilising a pragmatic test-retest experimental design, a sample of 41 Under-19 schoolboy players playing competitive rugby in the elite Super Eight Schools Rugby League in Harare, Zimbabwe, participated in the study. Physiological and game-specific skills tests which showed good to excellent relative reliability and acceptable absolute reliability, included: 20 m and 40 m speed, L-run, Vertical Jump (VJ), 60 s Push-Up, 2 kg Medicine Ball Chest Throw test (2 kg MBCT), Wall Sit Leg Strength test (WSLS), Repeated High Intensity Exercise test (RHIE), One Repetition Maximum Back Squat (1-RM BS) and Bench Press tests (1-RM BP), Yo-Yo Intermittent Recovery Level 1 test (Yo-Yo IRT L1), Tackling Proficiency test, Passing Ability Skill test and Running and Catching Ability skill test. All these tests are reliable and warrant inclusion in the SCRuM test battery for possible profiling of U19 schoolboy rugby players during the 'in-season' phase provided there is adequate participant familiarisation and test standardisation. The test-retest ICCs and measurement errors are generalisable to other young athletes in this population, making the tests useful for the evaluation of training and developmental effects of the measured constructs.

THE EFFECT OF COCONUT WATER INGESTION ON INTERMITTENT RUNNING EXERCISE PERFORMANCE

This research investigated the effects of coconut (COC) water ingestion during exhaustive intermittent running exercise performance. On separated two trials, 12 recreational male athletes (age 20 ± 2 years, body mass 59.9 ± 5.9 kg, fat percentage 11.8 ± 5.4%) completed a Yo-Yo Intermittent Recovery Test-Level 1 (Yo-yo IRT-1), running to exhaustion in a randomised counterbalanced order. The subjects were given 4 mL. kg-1 of either COC or carbohydrate-electrolyte (CHO-e) solution to be ingested prior to exercise. The distance covered, level of exhaustion, heart rate (HR), blood glucose, rating of perceived exertion (RPE), perceived arousal scale (FAS), and gastrointestinal discomfort (GI) were recorded intermittently during each trial. The distance covered with COC did not differ significantly from those data with CHO-e (CHO: 1066.7 ± 449.4 m; CHO-e:1106.7 ± 554.9 m, p = 0.85). There were also no significant differences in HR, RPE and FAS GI comfort between the trials (all p &gt; 0.05) expect for GI (p&lt; 0.05). The blood glucose was increased at the exhaustion of exercise, although, no significant difference was observed between the trials (p &gt; 0.05). Ingesting COC provided no ergogenic benefits during intermittent running exercise compared to CHO-e. The result of the current study suggests that COC ingestion and CHO-e were incapable of reducing perceive exercise intensity during the trials.

Association of phase angle and appendicular upper and lower body lean soft tissue with physical performance in young elite soccer players: a pilot study.

In soccer, a better understanding of the bioimpedance parameters with physical performance may be useful to efficiently monitor and interpret players' performance variation throughout a certain period of the season. Therefore, this study aimed to examine the association between phase angle (PhA) and arms and legs lean soft tissue (ALST and LLST) with physical performance in young elite soccer players. Fifteen young male elite soccer players (age: 14.2±1.2 years, BMI=20.51±1.38 kg/m2) participated in this investigation. Raw bioimpedance parameters (reactance, resistance, and PhA) were obtained by a bioelectrical impedance analysis (BIA) device. Then, ALST and LLST were estimated. All players underwent a physical testing battery including countermovement jump (CMJ), 10-minute and 20-minute sprint, and Yo-Yo Intermittent Recovery Test level 1 (YoYo IRTL1) in the domains of anaerobic and aerobic performance, respectively. The results showed that LST (total, arms and legs) positively correlated with CMJ (0.64<r<0.69; P<0.001) and negatively correlated with 10-m (-0.59<r<-0.63; P<0.05) and 20-minute sprint (-0.67<r<-0.73; P<0.001), while PhA positively correlated with CMJ (r=0.57; P<0.05) and negatively correlated (r=-0.54; P<0.05) only with 20-minute sprint. No significant association was found between the BIA-related parameters (PhA and LST) and Yo-Yo IRT level 1. The present findings highlight the existing association of PhA and LST with jumping and sprinting performance in young elite soccer players. This result supports the use of BIA-related measures as a simple and practical approach to monitoring anaerobic performance changes, rather than aerobic, over time throughout the season.

Positional running capacities and in-game demands of South African university level rugby players

Rugby is a complex contact sport consisting of varying intensities of locomotion, interspersed with stationary and contact periods. An increasing professionalisation of the sport even at university and school level has engendered a growing need to collect objective data regarding the physical attributes of rugby players. The aim of the study was to assess the positional running capacities and demands of university rugby players. Twenty-nine male rugby players (age: 22.5 ± 1.2 years; body mass: 96.1 ± 13.26 kg; stature: 182.6 ± 7.5 cm) completed a battery of tests, which included: 10 m + 40 m sprint, yo-yo intermittent recovery (Yo-Yo IRT), repeated sprint ability test (RSA), and had their in-game running demands evaluated. Positional differences between forwards and backs were reported (p<0.05) for Yo-Yo IRT: 19.2 ± 2 vs 21.1 ± 2; 10 m sprint: 1.7 ± 0.1s vs 1.6 ± 0.0s; 40 m sprint test: 5.4 ± 0.3s vs 5.1 ± 0.1s; 5 m RST: 738.9 ± 31.1m vs 767.3 ± 20.9m. Additionally, a significant difference in-game distances between forwards and the backs (absolute: 5564.1 ± 842.5m vs 6955.9 ± 780.9m; relative: 54.7 ± 9.0 m.min-1 vs 60.6 ± 8.7m.min-1) were obtained. The assessment of university-level rugby players showed that backline players tend to record higher aerobic capacity, acceleration and sprint values than forwards. Evidence has shown that during matches, backs tend to cover more distance and spend more time in each speed band than forwards. The findings were discussed in the light of their implications for competitive rugby performance.

Short and long-term differences in anthropometric characteristics and physical performance between male rugby players that became professional or remained amateur

Background/ObjectiveThe objective of this study was to investigate which anthropometric and physical performance variables characterised players that advanced to professional teams (professionals) and how these variables changed over time, compared to those that did not secure professional contracts (i.e. remained amateurs). MethodsDifferences in anthropometry, strength, speed, power and intermittent running ability in 83 male rugby players collected between 2015 and 2019 were determined using repeated measures analysis. ResultsWhen arriving for the first year of the program, forwards that went on to become professional players were older (0.4 ± 0.3 yr, mean ± 95% CI, p = 0.004), heavier (4.6 ± 2.5 kg, p < 0.001) and stronger (range 6.2–16.4%) than forwards that remained amateur. Professional forwards were also slower at sprinting (range −2.7–2.9%, p < 0.001) and had lower Yo-Yo IRT L1 (−10.8%, p = 0.03). When first arrived on the program, professional backs were taller (3.5 ± 1.8 cm, p < 0.001), heavier (4.6 ± 2.4 kg, p < 0.001) and faster over 20 m (−1.9 ± 1.7%, p = 0.03) and 30 m (−1.7 ± 1.6%, p = 0.04) compared to amateurs. Compared to amateurs, professionals had a smaller increase in body mass (−4.2 ± 2.0%, p < 0.001) and greater improvement in sprinting (3.7, 2.8, 2.8% over 10, 20 and 30-m, respectively) and Yo-Yo IRT L1 (14.7 ± 11.0%, p = 0.05) over 3 years training. ConclusionCharacteristics that are likely to assist players in becoming professionals include being older, heavier, taller and stronger.

A Comparison of Anthropometric and Performance Profiles between Elite and Sub-Elite Hurling Players

The aim of the current study was to identify the specific differences in anthropometric and performance profiles between elite and sub-elite hurling players with respect to position and level of play. One hundred and thirty-seven (n = 137) hurlers at the elite (n = 61) and sub-elite (n = 76) level completed a series of anthropometric [height, body mass, the sum of seven skinfolds, adipose tissue percentage estimates (%AT), fat-free mass estimations (FFM)) and performance ((countermovement jump height (CMJ), CMJ peak power (CMJ PP), CMJ relative peak power (CMJ RPP), acceleration (5, 10 and 20 m), and yo-yo intermittent recovery test level 1 (Yo-Yo IRT1)) assessments during the “early in-season” phase of the competition. Data were categorized into positions at both levels (full-backs, half-backs, midfielders, half-forwards, full-forwards). Multiple two-way ANOVA’s were performed to determine the effect of two fixed factors (level and position) on several anthropometric and performance variables. Elite level players had a significantly lower sum of seven skinfolds across all positions compared to the sub-elite (η2 = 0.441, large). At half-back, half-forward, and full-forward elite players had significantly lower %AT (η2 = 0.087–0.167, small–medium) and greater FFM (η2 = 0.040–0.065, small). Jump performance assessment showed elite players performed significantly better across all positions for CMJ (η2 = 0.526, large), CMJ PP (η2 = 0.385, large) and CMJ RPP (η2 = 0.520, large). When Yo-Yo IRT1 was considered, elite players completed an increased distance than the sub-elite across all positions (η2 = 0.526, large). The current data are the first to show differences in positional anthropometric and performance profiles between standards of play within hurling. Applied practitioners should consider these normative data when implementing training programs to maximize position-specific preparation for competition. Furthermore, these data could improve the considerations regarding the transitioning of players from the sub-elite to the elite level of play.

Importance of anthropometric features to predict physical performance in elite youth soccer: a machine learning approach

ABSTRACT The present study aimed to determine the contribution of soccer players’ anthropometric features to predict their physical performance. Sixteen players, from a professional youth soccer academy, were recruited. Several anthropometric features such as corrected arm muscle area (AMAcorr), arm muscle circumference (AMC) and right and left suprapatellar girths (RSPG and LSPG) were employed in this study. Players’ physical performance was assessed by the change of direction (COD), sprint (10-m and 20-m), and vertical jump (CMJ) tests, and Yo-Yo Intermittent Recovery Test level 1 (Yo-Yo IRT1). Using an extra tree regression (ETR) model, the anthropometric features permitted to accurately predict 10-m sprint, 20-m sprint and Yo-Yo IRTL 1 performance (p < 0.05). ETR showed that upper-body features as AMAcorr, and AMC affected 10-m and 20-m sprint performances, while lower-body features as RSPG and LSPG influenced the Yo-Yo IRTL 1 (Overall Gini importance ≥ 0.22). The model predicting COD and CMJ presented a poor level of prediction, suggesting that other factors, rather than anthropometric features, may concur to predict their changes in performance. These findings demonstrated that the upper- and lower-body anthropometric features are strictly related to sprint and aerobic fitness performance in elite youth soccer.

Do Changes in Fitness Status, Testosterone Concentration, and Anthropometric Characteristics Across a 16-Month Training Period Influence Technical Performance of Youth Soccer Players During Small-Sided Games?

Rodrigues Lopes, RA, Aoki, MS, Carling, C, Vaz Ronque, ER, and Moreira, A. Do changes in fitness status, testosterone concentration, and anthropometric characteristics across a 16-month training period influence technical performance of youth soccer players during small-sided-games? J Strength Cond Res 36(5): 1404-1409, 2022-This study examined the influence of changes in physical capacity, testosterone concentration, and anthropometric characteristics across a 16-month training period on technical performance of youth players during small-sided games (SSG). Thirty-five elite youth players (14.3 ± 0.2 years, 170 ± 6.2 cm, and 61 ± 6 kg) were assessed on 3 occasions (T1, T2, and T3) over the period. A multivariate canonical correlation (MCC) was used to assess the multiple associations between the criterion variable (SSG technical performance) and the predictor variable (physical capacity represented by the Yo-Yo Intermittent Recovery Test Level 1 [Yo-Yo IRT1], testosterone concentration, and anthropometric characteristics). Changes between T1 and T3 were retained for MCC analysis. Multivariate canonical correlation analysis revealed 2 significant functions (R2 = 0.42 and 0.36) indicating a significant relationship between predictor and criterion variables. Changes in Yo-Yo IRT1 performance were the main contributor to the predictor variable, whereas the frequency of tackles/interceptions contributed mostly to the criterion variable (SSG technical performance). These results showed that technical performance in SSG was influenced by changes in Yo-Yo IRT1 performance, suggesting the importance of monitoring in conjunction, intermittent exercise capacity, and technical performance in SSG in youth soccer players. In addition, the stability in technical performance during SSG observed over the experimental period suggests that practitioners could use SSG as a tool for systematic real-world monitoring of technical performance rather than isolated practice drills.

Anthropometric, physiological characteristics and rugby-specific game skills of schoolboy players of different age categories and playing standards

BackgroundRugby is increasingly gaining popularity among school-aged male junior players in countries hardly known for dominating international rugby, such as Zimbabwe. Given rugby combativeness, participating adolescents should possess qualities or skills commensurate with the physical demands of the sport for effective participation. This study investigated the independent and interactive effects of age category and playing standard on anthropometric, physiological characteristics and rugby-specific game skills among Zimbabwean athletes.MethodsTwo hundred and eight elite, sub-elite and non-rugby players competing at Under 16 and Under 19 age categories were assessed using the School Clinical Rugby Measure (SCRuM) test battery. Participants underwent height, sitting height, mass, skinfolds, speed, agility, upper-and-lower muscular strength and power, prolonged high-intensity intermittent running ability, tackling, passing and catching assessments in a cross-sectional experimental design.ResultsAge categories had significant main effect on all SCRuM test items except sum of seven skinfolds (p = 0.45, η2p = 0.003). Playing standard had significant main effects for all variables except height (p = 0.40, η2p = 0.01) and sum of seven skinfolds (p = 0.11, η2p = 0.02). Specifically, upper-and-lower muscular strength and power, prolonged high-intensity intermittent running ability, tackling, passing and catching improved with increasing playing standards. However, two-way analysis of variance only demonstrated significant interactions between the effects of age category and playing standards for vertical jump height (VJ) test, 2-kg medicine ball chest throw (2-kg MBCT) test, Yo-Yo intermittent recovery test level 1 (Yo-Yo IRT L1), and tackling and catching tests. Yo-Yo IRT L1, VJ, tackling and catching tests demonstrated greater discriminative ability among Under 16 s, whereas the 2-kg MBCT test showed better ability in Under 19 s.ConclusionAll SCRuM variables except skinfolds improved with age, highlighting relative sensitivity in differentiating older from younger athletes. However, the discriminative ability by playing standards for VJ, 2-kg MBCT, Yo-Yo IRT L1, tackling and catching ability tests was age-dependent. These findings informs on general attribute development in junior rugby players with age and on specific players attributes in need of monitoring for attainment of elite status at U16 or U19 level.

Half Soccer Season Induced Physical Conditioning Adaptations in Elite Youth Players.

This study aimed to investigate training-induced fitness changes and their relationship with training-competition load during half a soccer season (18 wks). Training load [heart rate (HR) and ratings of perceived exertion (RPE)] and match time were monitored, including 108 training (3 223 individuals) and 23 match sessions, in 38 youth elite male soccer players. Fitness variables were assessed before and after the study. Yo-Yo intermittent recovery test 1 (Yo-Yo IRT1) improved (P<0.001; 90%CI: 418-632 m; ES: 2.14). Anthropometrical, jump, sprint, and change-of-direction measures remained unchanged. Jump test correlated with sprint (r=0.74; P<0.001; SEE=3.38 m·s-1) and Yo-Yo IRT1 (r=-0.58; P=0.005; SEE=4.11 m) tests. Initial sum of 6 skinfolds was associated with changes in this same measure (r=-0.51; P<0.001; SEE=21%). Initial Yo-Yo IRT1 results were related to changes in Yo-Yo IRT1 (r=-0.84; P<0.001; SEE=10%) and match time played (r=0.44; P=0.033; SEE=445 m). Mean RPE records were related to training spent within 75-90% maximal HR (r=0.54; P<0.001; SEE=4%). The half-season was beneficial for endurance running performance but not for lower-limb strength-velocity production capacity. The more aerobically deconditioned players played fewer minutes of match, although they showed the greatest improvements in endurance performance. Non-soccer-specific, scientifically based, and individualized fitness programs in addition to soccer-specific training are recommended.

Anthropometric, physiological characteristics and rugby-specific game skills discriminating Zimbabwean under-16 male adolescent rugby players by level of competition

ObjectivesDespite growing popularity of adolescent rugby in Zimbabwean schools, little is known about qualities or skills of schoolboy rugby players and how they differ by competitive level. Therefore, the aim...

Influence of Different Methods to Determine Maximum Heart Rate on Training Load Outcomes in Basketball Players.

Berkelmans, DM, Dalbo, VJ, Fox, JL, Stanton, R, Kean, CO, Giamarelos, KE, Teramoto, M, and Scanlan, AT. Influence of different methods to determine maximum heart rate on training load outcomes in basketball players. J Strength Cond Res 32(11): 3177-3185, 2018-The summated-heart-rate-zones (SHRZ) approach uses heart rate (HR) responses relative to maximum HR (HRmax) to calculate the internal training load (TL). Age-predicted, test-derived, and session-based approaches have all been used to determine HRmax in team sports. The purpose of this study was to determine the effects of using age-predicted, test-derived, and session-based HRmax responses on SHRZ TL in basketball players. Semiprofessional, male basketball players (N = 6) were analyzed during the preparatory training phase. Six age-based approaches were used to predict HRmax including Fox (220 - age); Hossack (206 - [0.567 × age]); Tanaka (208 - [0.7 × age]); Nikolaidis (223 - [1.44 × age]); Nes (211 - [0.64 × age]); and Faff (209.9 - [0.73 × age]). Test-derived HRmax was taken as the highest HR during the Yo-Yo intermittent recovery test (Yo-Yo IRT), whereas session-based HRmax was taken as the higher HR seen during the Yo-Yo IRT or training sessions. Comparisons in SHRZ TL were made at group and individual levels. No significant group differences were evident between SHRZ approaches. Effect size analyses revealed moderate (d = 0.60-0.79) differences between age-predicted, test-derived, and session-based methods across the group and individually in 2 players. The moderate differences between approaches suggest age-predicted, test-derived, and session-based methods to determine HRmax are not interchangeable when calculating SHRZ. Basketball practitioners are encouraged to use individualized HRmax directly measured during field-based tests supplemented with higher HR responses evident during training sessions and games when calculating the SHRZ TL to ensure greatest accuracy.

Validity of the 30-15 Intermittent Fitness Test in Subelite Female Athletes.

Bruce, LM and Moule, SJ. Validity of the 30-15 intermittent fitness test in subelite female athletes. J Strength Cond Res 31(11): 3077-3082, 2017-The purpose of this study was to assess the suitability of the 30-15 Intermittent Fitness Test (IFT) as a test in netball using female athletes. Twenty-six female subelite netballers (mean age = 19.7 ± 4.6 years, mean height = 176.0 ± 6.1 cm, mean body mass = 69.7 ± 9.3 kg) completed the yo-yo intermittent recovery test level 1 (yo-yo IRT1) and the 30-15 IFT. Participants performed both assessments 1 week apart before the intervention and both tests 1 week apart after the training intervention (for a total of 4 testing sessions). A 6-week training intervention occurred between the test occasions. Pearson's correlations revealed significant very strong relationships between the 30-15 IFT and yo-yo IRT on both test occasions (test occasion 1: r = 0.71, p = 0.003 [95% confidence interval {CI} 0.35-0.89], magnitude of effect, most likely; test occasion 2: r = 0.72, p = 0.001 [95% CI: 0.42-0.88], magnitude of effect, most likely). Repeated-measures analysis of variances examining the effect of position on performance changes revealed main effects for test occasion and a position × test occasion interaction for both the 30-15 IFT and the yo-yo IRT1 (30-15 IFT: test occasion [F(1,14) = 28.68, p = 0.001, ηp = 0.67], position × test occasion interaction [F(2,14) = 9.38, p = 0.003, ηp = 0.57]; yo-yo IRT1: test occasion [F(1,15) = 11.72, p = 0.004, ηp = 0.44], position × test occasion interaction [F(2,15) = 9.96, p = 0.002, ηp = 0.57]). Results show that the 30-15 IFT is a suitable test for female netballers as it was able to detect improvements in performance after a training intervention, in addition to having a very strong significant relationship with the yo-yo IRT1.