Yo-Yo Intermittent Recovery Test Level Research Articles

Yo-Yo Intermittent Recovery Test Level 2 and Its Relationship With Other Typical Soccer Field Tests in Female Collegiate Soccer Players.

The ability to complete high-intensity running is essential for soccer. The Yo-Yo Intermittent Recovery Test Level 2 (YYIRT2) can measure this capacity, but there is limited information regarding this assessment in collegiate female soccer players. This study investigated the YYIRT2 as a measure of high-intensity running in this population, and its relationship to other soccer field tests. Twenty-one players from a Division I team were recruited. In addition to the YYIRT2, subjects completed linear (0-5, 0-10, and 0-30 m sprint intervals) and change-of-direction (pro-agility and 60-yard shuttle) speed tests, as well as the YYIRT Level 1 (YYIRT1), to assess relationships with YYIRT2 by correlations (p ≤ 0.05). The correlation of YYIRT1 with the speed tests was also assessed. The YYIRT1 and YYIRT2 were standardized using z-scores for comparison with elite benchmarks to investigate relative performance on each test. The YYIRT2 and YYIRT1 distances did not significantly correlate with those of the speed tests (r = -0.251 to 0.274). There was a large relationship between YYIRT2 and YYIRT1 distances (r = 0.582), although the explained variance was low (33.87%). Mean YYIRT2 z-scores (-4.29 ± 1.66) indicated a performance further from elite benchmarks than those of the YYIRT1 (-1.92 ± 1.61), and 90.5% (19 of 21) subjects performed relatively better in the YYIRT1 than YYIRT2. The YYIRT2 provided a more specific measure of high-intensity running to that of the YYIRT1 in collegiate female soccer players. Coaches may consider using the YYIRT2 to gauge and track progress of high-intensity running capabilities and create training programs to improve this ability in female players.

Are small-sided games an effective training methodology for improving fitness in hurling players? A comparative study of training methodologies

The current investigation compared the effects of specific small-sided games training versus generic continuous aerobic training on team sport related exercise performances. Forty-eight hurling players (age: 25 ± 6.4 years; height: 180.2 ± 20.4 cm; mass: 80.5 ± 3.2 kg; [Formula: see text]: 58.78 ± 3.05 ml·kg·min−1) completed either traditional continuous aerobic training ( n = 24) or team sport-specific small-sided game training ( n = 24), consisting of 4 × 4 min with 3-min active recovery periods completed twice per week. The following outcomes were measured at baseline (pre) and after 10 weeks (post): maximum oxygen uptake (ml·kg−1·min−1), running economy (ml·kg−1·min−1), maximal aerobic speed (km·h−1), Yo-Yo intermittent recovery test level 1 (m), Yo-Yo intermittent recovery test level 2 (m), repeated sprint ability (RSA; s), linear sprint speed over 5, 10 and 20 m (s) and counter-movement jump performance (cm). Training load was quantified by heart rate and rating of perceived exertion during all training sessions with no significant difference between groups ( P = 0.12). Small-sided game ( P = 0.002; d = 1.72; likely beneficial) had a likely beneficial effect for improving running economy (ml·kg−1·min−1) in contrast to the unclear effect for continuous training ( P = 0.94; d = 0.21; unclear). Small-sided game ( P = 0.04; d = 0.80; likely beneficial) had a likely beneficial effect for changes in RSAb (s) and RSAt (s) with these being in contrast to the likely negative effect for continuous training on similar measures ( P = 0.12; d = −2.01; likely negative). Continuous training had a trivial ( P = 0.72; d = 0.30; trivial) effect on Yo-Yo intermittent recovery test level 1 (m) performance in contrast to the likely beneficial effect seen for small-sided game ( P = 0.002; d = 1.72; likely beneficial). Small-sided game ( P = 0.001; d = 1.69; likely beneficial) resulted in a likely beneficial effect for Yo-Yo intermittent recovery test level 2 (m) performance with a likely negative effect for continuous training ( P = 0.004; d = −2.40; likely negative). The current study suggests that small-sided games are a time efficient and effective method of improving fitness characteristics within hurling cohorts.

The Influence of Rotations on Match Running Performance in Female Australian Football Midfielders.

With female Australian football (AF) gaining popularity, understanding match demands is becoming increasingly important. The aim of this study was to compare running performances of rotated and whole-quarter state-level female AF players during match quarters. Twenty-two state-level female AF midfielders wore Global Positioning System units during 14 games to evaluate activity profiles. The Yo-Yo Intermittent Recovery Test Level 1 (Yo-Yo IR1) was used as a measure of high-intensity running ability. Data were categorized into whole quarter, rotation bout 1, and rotation bout 2 before being further divided into quartiles. Players were separated into high- or low-Yo-Yo IR1 groups using a median split based on their Yo-Yo IR1 performance. Short (4-6 min), moderate (6-12 min), and long (12-18 min) on-field bout activity profiles were compared with whole-quarter players. High Yo-Yo IR1 performance allowed players to cover greater relative distances (ES = 0.57-0.88) and high-speed distances (ES = 0.57-0.86) during rotations. No differences were reported between Yo-Yo IR1 groups when players were required to play whole quarters (ES ≤ 0.26, likelihood ≤64%). Players who were on field for short to moderate durations exhibited greater activity profiles than whole-quarter players. Superior high-speed running ability results in a greater activity profile than for players who possess lower high-speed running ability. The findings also highlight the importance of short to moderate (4-12 min) rotation periods and may be used to increase high-intensity running performance within quarters in female AF players.

Hormonal (Cortical-Gonadotropic Axis) and Physical Changes With Two Years Intense Exercise Training in Elite Young Soccer Players.

Hammami, MA, Ben Abderrahman, A, Hackney, AC, Kebsi, W, Owen, AL, Nebigh, A, Racil, G, Tabka, Z, and Zouhal, H. Hormonal (cortical-gonadotropic axis) and physical changes with two years intense exercise training in elite young soccer players. J Strength Cond Res 31(9): 2388-2397, 2017-The aim of this study was to investigate the effects of 2 soccer-training seasons on physical fitness and hormone concentrations in elite youth soccer players. Twenty male elite soccer players (SP, age 14.5 ± 0.4 years) and 20 male control subjects (CS, age 14.3 ± 0.3 years) participated in the study. Anthropometric measurements, aerobic (Yo-Yo Intermittent Recovery Test Level 1 [YYIRT1]) and anaerobic soccer relevant performances (jump and sprint tests), blood testosterone (T), cortisol (C), sex hormone binding globulin (SHBG), and T/C ratio were assessed 5 times (from T0 to T4) during 2 competitive seasons. Significant differences from basal values (Δ) of T, SHBG, and C between SP and CS were observed (p < 0.01). Additionally, T and T/C ratio changes were positively correlated with physical performance (p ≤ 0.05). In conclusion, as expected, higher T concentration and greater power performance were observed in the soccer players group compared with controls. Our findings also show that the T concentrations and power performance outcomes co-vary positively over the 2 soccer seasons in soccer players.

Effect of Carbohydrate, Caffeine, and Carbohydrate + Caffeine Mouth Rinsing on Intermittent Running Performance in Collegiate Male Lacrosse Athletes.

Dolan, P, Witherbee, KE, Peterson, KM, and Kerksick, CM. Effect of carbohydrate, caffeine, and carbohydrate + caffeine mouth rinsing on intermittent running performance in collegiate male lacrosse athletes. J Strength Cond Res 31(9): 2473-2479, 2017-Recently, an interest has developed in the potential to rinse the oral cavity with key nutrients to impact various types of exercise and presumably sporting performance. Although multiple studies examining carbohydrate mouth rinsing have been completed, conflicting evidence surrounding caffeine mouth rinsing persists, and no research has explored its ability to impact high-intensity, intermittent running performance. This study investigated the independent and synergistic ability of carbohydrate and caffeine mouth rinsing to improve intermittent running performance. The Yo-Yo Intermittent Recovery Test-Level 1 (Yo-Yo Level 1) was completed in 10 collegiate (National Collegiate Athletic Association [NCAA] Division II) male lacrosse players after a 10-second mouth rinse with a solution of either carbohydrate (CHO), caffeine (CAF), carbohydrate + caffeine (CHO + CAF), placebo (H2O), or a no rinse control (CON). No significant improvements in Yo-Yo IRT-1 performance were found (p > 0.05). Perceptual indications of effort (i.e., rating of their perceived exertion [RPE]) were significantly lower (p ≤ 0.05) in CHO and CHO + CAF when compared with CON after speed level 11. Interestingly, RPE levels were nonsignificantly lower in all but one level of the Yo-Yo Level 1 for CHO in comparison with other groups. Carbohydrate and caffeine mouth rinsing seems to exert no impact on running performance before maximal intermittent running in a group of male collegiate lacrosse players.

Monitoring player fitness, fatigue status and running performance during an in-season training camp in elite Gaelic football

ABSTRACTObjectives: To examine selected perceptual and physiological measures to monitor fitness, fatigue and running performance during an in-season training camp in elite Gaelic football. Methods: Twenty-two elite Gaelic football players were monitored for training load, perceived ratings of wellness, heart rate variability (HRV; LnSD1), heart rate recovery (HRR), exercise heart rate (HRex), lower limb muscular power (CMJ) and global positioning system (GPS) variables. The Yo-Yo intermittent recovery test level 1 (Yo-YoIR1) was assessed pre and post the training camp. With specific small-sided games (SSG) used as a measure of running performance. Results: During the camp, HRex decreased (−12.2%), HRR increased (+10.3%), CMJ decreased (−8.1%) and pretraining LnSD1 (+14.1%) increased during the camp period. Yo-YoIR1 performance (+19.7%), total distance (TD) (+9.4%), high-speed distance (HSD) (+12.1%) and sprint distance (SPD) (+5.8%) within SSG improved as the camp progressed. Δ HRex and Δ HRR were correlated with Δ Yo-YoIR1 (r = 0.64; – 0.55), ΔHSD (r = 0.44; −0.58) and Δ SPD (r = 0.58; −0.52).There were large correlations between Δ wellness and Δ Yo-YoIR1 (r = 0.71), Δ TD (r = 0.68) and Δ SPD (r = 0.68). Conclusions: Daily variations in training load measures across the camp period were shown to systematically impact player’s physiological, performance and wellness measures.

The Influence of Training Age on the Annual Development of Physical Qualities Within Academy Rugby League Players.

Till, K, Darrall-Jones, J, Weakley, JJ, Roe, GA, and Jones, BL. The influence of training age on the annual development of physical qualities within academy rugby league players. J Strength Cond Res 31(8): 2110-2118, 2017-Previous research in academy rugby league players has evaluated the development of physical qualities according to chronological age. However, no study has considered the training age, defined as the number of formalized years of strength and conditioning training, of these players. Therefore, the purpose of this study was to present and compare the annual changes in physical qualities of academy rugby league players according to training age. Sixty-one academy players undertook a fitness testing assessment, including anthropometric (height, body mass, sum of 4 skinfolds) and physical (10 and 20 m sprint, 10m momentum, vertical jump, Yo-Yo intermittent recovery test level 1 [Yo-Yo IRTL1], one-repetition maximum [1RM] squat, bench press and prone row) measures at the start of preseason on 2 consecutive annual occasions. Players were categorized into one of 3 training age groups (i.e., 0, 1, or 2 years) and were analyzed using magnitude-based inferences. Almost certain, very likely or likely annual improvements were identified for body mass, 10m momentum, Yo-Yo IRTL1, vertical jump, and all strength measures for the 3 training age groups. When training age groups were compared, 1 year showed possibly or likely lower strength increases than 0 years training age. However, the 2 years training age group demonstrated possibly or likely increased strength changes compared with 1 year. These findings suggest that training age is an important consideration for strength and conditioning practitioners but it is likely to be a combination of chronological age, biological maturity, and training experience alongside dynamic interplayer variability that influences the physical development of academy rugby league players.

Effects of In-Season Explosive Strength Training on Maximal Leg Strength, Jumping, Sprinting, andIntermittent Aerobic Performance in Male Handball Athletes.

Background Team handball is an intense ball sport with specific requirements on technical skills, tactical understanding, and physical performance. The ability of handball players to develop explosive efforts (e. g. sprinting, jumping, changing direction) is crucial to success. Objective The purpose of this pilot study was to examine the effects of an in-season high-intensity strength training program on the physical performance of elite handball players. Materials and methods Twenty-two handball players (a single national-level Tunisian team) were randomly assigned to a control group (CG; n = 10) or a training group (TG; n = 12). At the beginning of the pilot study, all subjects performed a battery of motor tests: one repetition maximum (1-RM) half-squat test, a repeated sprint test [6 × (2 × 15 m) shuttle sprints], squat jumps, counter movement jumps (CMJ), and the Yo-Yo intermittent recovery test level 1. The TG additionally performed a maximal leg strength program twice a week for 10 weeks immediately before engaging in regular handball training. Each strength training session included half-squat exercises to strengthen the lower limbs (80 - 95 % of 1-RM, 1 - 3 repetitions, 3 - 6 sets, 3 - 4 min rest between sets). The control group underwent no additional strength training. The motor test battery was repeated at the end of the study interventions. Results In the TG, 3 parameters (maximal strength of lower limb: η² = 0.74; CMJ: η² = 0.70, and RSA best time: η² = 0.25) showed significant improvements, with large effect sizes (e. g. CMJ: d = 3.77). A reduction in performance for these same 3 parameters was observed in the CG (d = -0.24). Conclusions The results support our hypothesis that additional strength training twice a week enhances the maximal strength of the lower limbs and jumping or repeated sprinting performance. There was no evidence of shuttle sprints ahead of regular training compromising players' speed and endurance capacities.

The effect of air pollution on diurnal variation of performance in anaerobic tests, cardiovascular and hematological parameters, and blood gases on soccer players following the Yo–Yo Intermittent Recovery Test Level-1

ABSTRACTThis study aimed to investigate the effect of air pollution on diurnal variation of performance in anaerobic tests, cardiovascular and hematological parameters, and blood gases on soccer players following the Yo–Yo Intermittent Recovery Test Level-1 (YYIRT1). In a randomized order, 11 healthy soccer players (mean age: 21.8 [range: 20–24] years; height: 178.00 [range: 1.64–1.83] cm; body mass index [BMI]: 23.57 [range: 20.45–28.03] kg.m−2) performed a YYIRT1 at two different times of day (TOD) (08:00 h and 18:00 h) in two areas (i.e. polluted (PA) and non-polluted (NPA)) with a recovery period of ≥ 72 h in between, to determine the maximal oxygen uptake (VO2max). In each test session: resting oral temperature is measured, anaerobic performances (pre- and post-YYIRT1) were performed, cardiovascular parameters and blood samples were collected at: rest, 3 min and 60 min after the YYIRT1, to assess blood gases and hematological parameters. Our results showed that, agility performance, VO2max, red blood cells (RBC), hemoglobin (Hb), pH, and bicarbonate levels (HCO3−) decrease significantly (p < 0.001) following the YYIRT1 in PA compared to NPA. Likewise, the heart rate (HR), systolic blood pressure (SBP), platelets (PLT), white blood cells (WBC), neutrophiles (NEUT), lymphocytes (LYM), and partial pressure of CO2 levels (PvCO2) were significantly higher (p < 0.001) in PA. This effect was slightly accentuated at 18:00 h for some parameters (i.e. Agility, HCO3−, HR, PvCO2, RBC, SBP). However, performances of sprint and Sargent jump test (SJT), oral temperature, rate of perceived exertion scales (RPE), partial pressure of O2 (PvO2), diastolic blood pressure (DBP), and monocytes (MON) were not affected by pollution (p > 0.05). In conclusion, pollution seems to be critical for health stability and performance in response to YYIRT1 especially in the evening and the winter season. Therefore, coaches and athletes should draw attention to the potential importance of land use planning in their training sessions and competitions in the morning in polluted area to minimize the risk of pollution exposure.

Six weeks of β-alanine supplementation did not enhance repeated-sprint ability or technical performances in young elite basketball players.

Supplementation with β-alanine plays an important role as a precursor of carnosine, the most effective intramuscular buffer, and has been seen as a potential ergogenic aid, especially for high-intensity modalities such as basketball. Thus, the aim of the present study was to investigate the effects of 6 weeks of β-alanine supplementation on repeated sprint ability (RSA) and technical performances in young elite Brazilian basketball players. In total, 27 young basketball players (17±1 years) were randomized into a β-alanine group (Gβ - 6.4 g day-1 of β-alanine) and a placebo group (GP - 6.4 g day-1 of dextrose). Before and after the supplementation period the athletes performed a RSA test composed of ten 30 m sprints with two 180° changes of direction interspaced by 30 s of recovery. During the recovery period (i.e., after the sprints) the athletes performed a countermovement jump (CMJ) and a set of three free throws. After 48 h they performed a Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1). Both groups increased the distance covered in the Yo-Yo IR1 after the supplementation period ( p = 0.001). On the other hand, both groups presented impairment in RSA time-performance (total time, best time, and mean time, p ≤ 0.04), while no significant changes were observed for technical task performances (i.e., CMJ and free throws) ( p ≥ 0.07). No between-group interactions were observed for any variable measured ( p ≥ 0.31). Thus, 6 weeks of β-alanine supplementation did not improve RSA or technical performances in young elite basketball players.

Repeated-sprint training in the fasted state during Ramadan: morning or evening training?

The present study assessed the optimal moment of the day for repeated-sprint training in the fasted state during Ramadan. Thirty amateur soccer players were randomly assigned to a morning training group (MTG, training at ~08:00 a.m., N.=10), an evening training group (ETG, training around 06:00 p.m., N.=10), and a control group (N.=10). Training sessions, conducted on alternate days, consisted of 3 sets of 6×40-m shuttle sprints (2×20 m with 180° direction changes). A 20-second passive recovery and a 4-minute passive recovery were allowed between repetitions and sets, respectively. Before and after Ramadan, performance was assessed at both 08:00 a.m. and 06:00 p.m. by Countermovement Jump (CMJ), Repeated-Sprint Test (RST), and Yo-Yo Intermittent Recovery Test Level 1 (YYIRT1). After Ramadan, YYIRT1 performances were enhanced for both groups in the morning (7.82% and 6.29% for MTG and ETG, respectively, P<0.05), and in the evening (6.61% and 11.20%, respectively, P<0.05). Relative changes in YYIRT1 (P=0.33) and RST (-2.13% and -3.44% for MTG and ETG, respectively, P=0.49) at the specific time of training were similar for both groups. No differences were observed in CMJ performances before and after Ramadan for any group (P>0.05). Morning or evening repeated-sprint training conducted in the fasted state during Ramadan enhanced soccer-specific endurance similarly.

Soccer-related performance in eumenorrheic Tunisian high-level soccer players: effects of menstrual cycle phase and moment of day.

This study aimed to examine the combined effects of menstrual cycle phase and moment of day on female soccer players' performances in the five-jump test (5JT), the repeated shuttle-sprint ability test (RSSA), and the Yo-Yo intermittent recovery test level 1 (YYIRT1). Eleven eumenorrheic Tunisian high-level soccer players volunteered to participate. Each subject individually participated in three testing periods: one in the early follicular phase (menses), one in the late follicular phase, and another in the luteal phase. In each period, two test sessions were conducted: one at 07:30 and another at 17:30. The testing routines included the 5JT, the RSSA, and the YYIRT1. None of the measured variables were altered due to menstrual cycle phase (all P>0.05). Mean time during RSSA was significantly lower in the afternoon session compared to the morning session (8.48±0.27 s and 8.77±0.34 s, respectively, P<0.001), while 5JT performance was significantly higher in the afternoon compared to the morning (9.08±0.58 m and 8.60±0.56 m, respectively, P<0.001). Soccer-specific endurance as well as jumping and repeated sprinting ability of Tunisian female high-level soccer players are not affected due to menstrual cycle phase neither in the morning nor in the afternoon.

Short- or long-rest intervals during repeated-sprint training in soccer?

The present study compared the effects of two repeated-sprint training (RST) programs, differing in duration of the between-sprint rest intervals, on various soccer-related exercise performances. For 5 weeks during the competitive season, twenty-nine young trained male soccer players either replaced two of their habitual fitness conditioning sessions with RST characterized by short (5–15; n = 9) or long (5–30; n = 10) rest intervals, or served as control (n = 10). The 5–15 and 5–30 protocols consisted of 6 repetitions of 30-m (~5 s) straight-line sprints interspersed with 15 s or 30 s of passive recovery, respectively. 5–15 improved 200-m sprint time (2.0±1.5%; p<0.05) and had a likely positive impact on 20-m sprint performance, whereas 5–30 lowered the 20-m sprint time (2.7±1.6%; p<0.05) but was only possibly effective for enhancing the 200-m sprint performance. The distance covered during the Yo-Yo Intermittent Recovery Test Level 2 increased following 5–15 (11.4±5.0%; p<0.05), which was possibly better than the non-significant 6.5% enhancement observed in 5–30. Improvements in the total time of a repeated-sprint ability test were possibly greater following 5–30 (3.6±0.9%; p<0.05) compared to 5–15 (2.6±1.1%; p<0.05). Both RST interventions led to similar beneficial (p<0.05) reductions in the percentage decrement score (~30%) of the repeated-sprint ability test as well as in blood lactate concentration during submaximal exercise (17–18%). No changes occurred in the control group. In soccer players, RST over a 5-week in-season period is an efficient means to simultaneously develop different components of fitness relevant to match performance, with different benefits induced by shorter compared to longer rest intervals.

Relationship between field tests and match running performance in high-level young Brazilian soccer players.

The main aim of this study was to analyze the relationship between field tests and match running performance using computational tracking technology in high-level young Brazilian soccer players. Twenty-five young male Brazilian soccer players participated in this study (U-15, N.=13; U-17, N.=12). In the same week, the players were submitted to field tests and actual matches. The field tests were: Maximum Speed (10-30 m), Zig-Zag, Running-based Anaerobic Sprint Test, and Yo-Yo Intermittent Recovery Test Level 1. Additionally, participants performed actual soccer match-play. Match running performance was collected using a fixed video-camera. Subsequently, computerized tracking video-analysis (30 Hz) was utilized to identify each physical performance indicator. Pearson's correlation and linear regression were used for statistical analysis. The results showed that the majority of field tests were not related to match running performance. The Zig-Zag Test, Running-based Anaerobic Sprint Test, and Yo-Yo Intermittent Recovery Test level 1 seem to be the most specific tests (r=0.41-0.47), however the explanatory powers of these field tests in relation to match running performance were low (R2=17-22%). Assessment of match running performance should be included in the evaluation periods of young soccer players, together with the most specific tests reported.

The effect of morphological characteristics on the physical and physiological performance of Turkish soccer referees and assistant referees

Physical fitness and physiological status play an important role in the referees’ performance. Therefore, the aim of this study was to analyze the body structure and morphological characteristics of Turkish Ssccer refereesand assistant referees and to determine the effect of these variables on physical performance. A sample of 158 male referees and 55 asisstant referees (mean age 31.8 ± 4.2 and 37.4 ± 3.3 years)was evaluated. Physical assesment were conducted using the Yo-Yo Intermittent Recovery Test Level 1 (YYIRTL1) and Repeated Sprint Ability (RSA) for referees and Active Recovery Intermittent Endurance Test (ARIET) and the RSA for assistant referees. We analyzed heart rate assesments. The measures used to assess morphological characteristics were age, weight, body mass index (BMI), body fat (BF), body mass, and fat free mass.The ANOVA test (Tukey test)was used to determine the result. Correlations between the referees’ fitness test performance and their morphological characteristics were examined using Pearson’s correlation (p<0.05). To result of this study, point to the existence of a strong correlation between morphological and physical and physiological characteristics. According to the literature, we found that greater BF and a higher BMI may negatively affect areferee’s running performance.

Relationships and Predictive Capabilities of Jump Assessments to Soccer-Specific Field Test Performance in Division I Collegiate Players.

Leg power is an important characteristic for soccer, and jump tests can measure this capacity. Limited research has analyzed relationships between jumping and soccer-specific field test performance in collegiate male players. Nineteen Division I players completed tests of: leg power (vertical jump (VJ), standing broad jump (SBJ), left- and right-leg triple hop (TH)); linear (30 m sprint; 0–5 m, 5–10 m, 0–10, 0–30 m intervals) and change-of-direction (505) speed; soccer-specific fitness (Yo-Yo Intermittent Recovery Test Level 2); and 7 × 30-m sprints to measure repeated-sprint ability (RSA; total time (TT), performance decrement (PD)). Pearson’s correlations (r) determined jump and field test relationships; stepwise regression ascertained jump predictors of the tests (p < 0.05). All jumps correlated with the 0–5, 0–10, and 0–30 m sprint intervals (r = −0.65–−0.90). VJ, SBJ, and left- and right-leg TH correlated with RSA TT (r = −0.51–−0.59). Right-leg TH predicted the 0–5 and 0–10 m intervals (R2 = 0.55–0.81); the VJ predicted the 0–30 m interval and RSA TT (R2 = 0.41–0.84). Between-leg TH asymmetry correlated with and predicted left-leg 505 and RSA PD (r = −0.68–0.62; R2 = 0.39–0.46). Improvements in jumping ability could contribute to faster speed and RSA performance in collegiate soccer players.

Evolution of Determinant Factors of Repeated Sprint Ability.

The aim of this study was to investigate the changes in the relationships between repeated sprint ability (RSA) and anthropometric measures as well as fitness qualities in soccer players. Twenty-one professional soccer players performed several anthropometric and physical tests including countermovement vertical jumps (CMJs), a straight-line 30 m sprint (T30), an RSA test (6 x 20 + 20 m with 20 s recovery), a progressive isoinertial loading test in a full squat, a Yo-Yo Intermittent Recovery Test Level-1 (YYIRT-1) and a 20 m shuttle run test (20mSRT). The mean (RSAmean), the fastest (RSAbest), each single sprint time, and the percentage in a sprint decrease (%Dec) in the RSA test were calculated. RSAbest correlated significantly with RSAmean (r = .82) and with all single sprints (p < 0.05), showing a downward trend as the number of sprints performed increased. No significant relationship was observed between the %Dec and RSA performance. CMJs and the T30 also showed a correlation with RSA performance, whereas lower limb strength did not show any relationship with RSA performance. RSAmean showed significant (p < 0.05) relationships with body mass (r = .44), adiposity (r = .59) and the YYIRT-1 (r = -.62), increasing as the number of repeated sprints increased. The 20mSRT showed minimal relationships with RSA performance. In conclusion, maximal sprint capacity seems to be relevant for the RSA performance, mainly in the first sprints. However, high intermittent endurance capacity and low adiposity might help enhance the RSA performance when increasing the number of repeated sprints.

The intensity and match load comparison between high spinal cord injury and non-spinal cord injury wheelchair basketball players: a case report.

This is a comparative case study between one high spinal cord injury (SCI) and two non-SCI players during an official wheelchair basketball (WB) match. The aim of the study was to calculate the differences in the absolute and relative HR responses and in the match load among one SCI and two non-SCI players in the same WB match. The study was conducted with first-division WB players in Vitoria-Gasteiz, Spain (2014). All of the participants had played the whole official WB match. Absolute heart rate (HR) in the test (10 m Yo-Yo Intermittent Recovery Test Level 1, YYIR1 10 m) as well as absolute and relative HR and match load (ML) were recorded for these three players in an official WB match. The HRpeak and mean during the YYIR1 10 m test and the whole WB match were lower for the SCI player than the non-SCI players. However, as opposed to absolute HR values, relative HR values and ML reported very similar responses among SCI and non-SCI values. Moreover, in the high-intensity HR zone the values were similar among the three players but not in the low (<75% of HRpeak), moderate (75-85% of HRpeak) and maximal (>95% of HRpeak) HR zones. Although the absolute HR values were lower for the SCI player, the relative values and the ML were similar for all the players. Therefore, it could be necessary to use relative HR values to quantify the intensity of efforts in the WB matches.

Yo-Yo Intermittent Recovery Test thresholds to determine positional internal match loads of semiprofessional soccer players

The aim of this study was to use heart rates and Yo-Yo Intermittent Recovery test level 1 (Yo-Yo IR1)-derived thresholds to determine the positional internal match loads of semi-professional soccer players. Players completed a Yo-Yo IR1 while wearing a portable gas analyser. Heart rates (HR) that corresponded to the first and second ventilatory thresholds were used to classify internal loads into low- (LI HR zone), moderate- (MI HR zone) and high-intensity zones (HI HR zone). During 12 soccer matches it was found that attackers (n = 17) spent more time in the LI HR zone (3386 s; 62%; P < 0.05) than defenders (2155 s; 40%; n = 36) and midfielders (2425 s; 42%; n = 41). The attackers spent less time in the HI HR zone (260 s; 4%; P < 0.05) than the defenders (964 s; 15%). Midfielders (2444 s; 44%) and defenders (2364 s; 41%) spent more time in the MI HR zone than attackers (1854 s; 44%). This study is the first to show that the Yo-Yo IR1 test can be used to determine individual, physiologically defined intensity zones to determine positional differences in the internal match loads of soccer players.

Effects of in-season short-term aerobic and high-intensity interval training program on repeated sprint ability and jump performance in handball players.

This study examined the effects of a 7-week in-season aerobic and high-intensity interval-training program on performance tests linked to successful handball play (e.g., repeated sprint and jumping ability). Thirty participants (age 17.0±1.2 years, body mass 81.1±3.4 kg, height 1.82±0.07 m) performed a Yo-Yo Intermittent Recovery Test level 1 (Yo-Yo IR1), a squat (SJ) and a Countermovement Jump Test (CMJ), as well as a repeated Sprint Ability Test (RSA). From this, maximal aerobic speed (MAS, reached at the end of the Yo-Yo IR1), jumping ability, best time in a single sprint trial (RSAbest), total time (RSATT) and the performance decrement (RSAdec) during all sprints were calculated. Later, subjects were randomly assigned to a control group (CG; N.=15) performing their normal training schedule (5 weekly sessions of ~90 minutes of handball training) or an experimental group (EG; N.=15). The EG performed two 30 min sessions per week of high-intensity aerobic exercises at 100-130% of MAS in addition to their normal training schedule. A significant improvement in MAS (d=4.1), RSAbest (d=1.9), RSATT (d=1.5) and RSAdec (d=2.3) after the training period was demonstrated. Also, significant interaction effects (time x group) were found for all parameters as the EG significantly improved performances in all tests after training. The greatest interaction effects were observed in MAS (η2=0.811) and CMJ (η2=0.759). No relevant changes in test performances were found in the CG (mean d=-0.02). These results indicate that individually speed-controlled aerobic and interval training is effective for improving specific handball performance.