Yo-Yo Intermittent Recovery Test Level Research Articles

Seasonal variation in fitness in a women's National League hockey squad

Regular fitness assessments are crucial in monitoring the efficacy of a training programme, judging return to play after injury and motivating athletes. The data can be used by practitioners to...

Performance and physiological responses to repeated-sprint exercise: a novel multiple-set approach

We investigated the acute and chronic responses to multiple sets of repeated-sprint exercise (RSE), focusing on changes in acceleration, intermittent running capacity and physiological responses. Ten healthy young adults (7 males, 3 females) performed an incremental test, a Yo-Yo intermittent recovery test level1 (Yo-Yo IR1), and one session of RSE. RSE comprised three sets of 5 × 4-s maximal sprints on a non-motorised treadmill, with 20 s of passive recovery between repetitions and 4.5 min of passive recovery between sets. After ten repeated-sprint training sessions, participants repeated all tests. During RSE, performance was determined by measuring acceleration, mean and peak power/velocity. Recovery heart rate (HR), HR variability, and finger-tip capillary lactate concentration ([Lac(-)]) were measured. Performance progressively decreased across the three sets of RSE, with the indices of repeated-sprint ability being impaired to a different extent before and after training. Training induced a significant increase (p < 0.05) in all indices of performance, particularly acceleration (21.9, 14.7 and 15.2% during sets 1, 2 and 3, respectively). Training significantly increased Yo-Yo IR1 performance by 8% and decreased Δ[Lac(-)]/work ratio (-15.2, -15.5, -9.4% during sets 1, 2 and 3, respectively) and recovery HR during RSE. There were strong correlations between Yo-Yo IR1 performance and indices of RSE performance, especially acceleration post-training (r = 0.88, p = 0.004). Repeated-sprint training, comprising only 10 min of exercise overall, effectively improved performance during multiple-set RSE. This exercise model better reflects team-sport activities than single-set RSE. The rapid training-induced improvement in acceleration, quantified here for the first time, has wide applications for professional and recreational sport activities.

The Effect of Iron Supplementation During Menses on Iron Markers and Performance in Active Females

Fifty percent of all active females may have some form of iron deficiency, which could lead to a compromise in athletic performance. PURPOSE: The purpose of the study was to determine the effect of 7 days iron supplementation during menses on blood markers for iron status, high intensity exercise performance, and heart rate recovery (HRREC). METHODS: Twenty five active females (age=21.1 yrs, VO2max ≥ 45 mL.kg-1.min-1 or 8 hrs vigorous training/week) completed a Yo-Yo Intermittent Recovery Test Level 2 (YY2) and a blood draw before and after 7 days of iron supplementation (IRON, 65mg ferrous sulfate N=9), or a placebo (PLC, N=16). Blood was analyzed for blood lactate, hemoglobin (Hb), serum ferritin (sFer) and Hematocrit. Participants also completed a 7-day physical activity recall, O'Connor subjective fatigue scales (PF), muscle soreness scale (MS), and a supplement adherence journal. Heart rate was monitored before, during and after the YY2. RESULTS: There were no significant differences between IRON and PLC groups at baseline. ANOVA indicated significant differences between groups in sFer (p= 0.008) and Hb (p= 0.040) following 7 days of treatment. MS tended to decrease in IRON (p=0.052) and increase in PLC (p=0.051). CONCLUSION: One week of treatment had a positive effect on sFer and Hb levels in the IRON group. The impact of iron supplementation on MS, HRREC, PF and YY2 remains unclear at this time. Funded by Morrison Bruce Center and JMU CISAT Mini Grant Award.

Direct Validity of the Yo-Yo Intermittent Recovery Test in Young Team Handball Players

The aim of this study was to examine the possible association between Yo-Yo intermittent recovery test level 1 performance (distance covered, Yo-Yo IR1) and match activities (direct validity) in young male team handball players. Eighteen young male players (age 14.3 +/- 0.5 years, body mass 64 +/- 28.7 kg, height 174 +/- 6 cm, body fat 11.2 +/- 3.9%) took part in this study. Players' match activities were videotaped during an experimental tournament (6 games/player) and analyzed using a computerized system. Games and Yo-Yo IR1 heart rates (HRs) (short-range telemetry, HR) and blood lactate concentrations ([la]b) were assessed throughout and at selected times of the games, respectively. Peak Yo-Yo IR1 HR was assumed as representative of individual maximal HR (HRmax). Mean and peak game HRs were 174 +/- 3 and 198 +/- 2 b.min, which corresponded to 87 and 99% of HRmax, respectively. Yo-Yo IR1 performance (1,831 +/- 373 m) was significantly related (r = 0.88, p < 0.01) to total game distance (1,921 +/- 325 m). Post-game (9.2 +/- 2.3 mmol.L) and Yo-Yo IR1 (8.8 +/- 1.6 mmol.L) [la]b were significantly related (r = 0.51, p < 0.05). These findings demonstrated the direct validity of Yo-Yo IR1. Consequently, Yo-Yo IR1 test may be considered as a team handball test relevant for the assessment of intermittent high-intensity endurance in young male team handball players.

Effects of Intermittent-Endurance Fitness on Match Performance in Young Male Soccer Players

The purpose of this study was to examine the effect of specific endurance (Yo-Yo Intermittent recovery test level 1, Yo-Yo IR1) on match performance in male youth soccer. Twenty-one young, male soccer players (age 14.1 +/- 0.2 years) were involved in the study. Players were observed during international championship games of corresponding age categories and completed the Yo-Yo IR1 on a separate occasion. Physical (distance coverage) and physiological match demands were assessed using Global Positioning System technology and heart rate (HR) short-range telemetry, respectively. During the match (two 30-minutes halves), players covered 6,204 +/- 731 m, of which 985 +/- 362 m (16%) were performed at high intensities (speed >13 kmxh, HIA). A significant decrement (3.8%, p = 0.003) in match coverage was evident during the second half. No significant (p = 0.07) difference between halves was observed for HIA (p = 0.56) and sprint (speed >18 kmxh, SPR) distances. During the first and second halves, players attained the 86 +/- 5.5 and 85 +/- 6.0% of HRmax (p = 0.17), respectively. Peak HR during the first and second halves were 100 +/- 4 and 99.4 +/- 4.7% of HRmax, respectively. Yo-Yo IR1 performance (842 +/- 352 m) was significantly related to match HIA (r = 0.77, p < 0.001) and total distance (r = 0.65, p = 0.002). This study's results showed that specific endurance, as determined by Yo-Yo IR1 performance, positively affects physical match performance in male young soccer players. Consequently, the Yo-Yo IR1 test may be regarded as a valid test to assess game readiness and guide training prescription in male youth soccer players.

Generic Versus Small-sided Game Training in Soccer

The aim of this study was to compare 7 weeks of soccer-specific small-sided game (SSG) and mixed generic fitness training, on selected physiological, perceptual and performance variables. Twenty-five elite youth players were randomly allocated to either a SSG (coach selected) or generic training group (GTG), in a randomised, parallel matched-group design. In addition to normal training, each group completed two fitness training sessions per week of equal duration. Players completed a V O (2 max) treadmill test, Multistage Fitness Test (MSFT), Yo-Yo Intermittent Recovery Test Level 1 (YYIRTL1), 12x20 m test of repeated-sprint ability (RSA) and 20-m sprint test pre and post training. Training heart rate, perceived training intensity and perceptual fatigue measures were recorded throughout the training period. There were no differences in training heart rate or perceptual well-being measures. However, the GTG did perceive their training to be more intense than SSG. There were no changes in either group for V O (2 max), MSFT, RSA or sprint performance. However, there were improvements in YYIRTL1 performance for both groups over time, but not between groups. The results show that both types of training are equally effective at improving pre-season YYIRTL1 performance, despite GTG being perceived to be more intense.

The Yo-Yo Intermittent Recovery Test (Level 1) to discriminate elite junior Australian football players

The Yo-Yo Intermittent Recovery (IR) Test is currently used to assess endurance performance in team sport athletes. However, to date, no data has been presented on its application to an elite junior Australian football (AF) playing group. Therefore, the aim of this study was to evaluate the Yo-Yo Intermittent Recovery Test Level 1 (IR1) ability to discriminate between junior AF players at two different playing standards and a group of non-athletic healthy males. Sixty age matched participants (16.6 ± 0.5 years) spread over three groups (20 per group): elite junior footballers; sub-elite junior footballers; and non-athletic healthy males participated in this study. Participants undertook a single Yo-Yo test performance on an indoor basketball court for each group. A one-way ANOVA with Scheffe's post hoc analysis revealed the elite junior footballers covered a significantly greater total distance ( p < 0.001) and completed a significantly greater number of high-intensity efforts ( p < 0.001) in comparison to their sub-elite counterparts, whilst both AF groups performed significantly better ( p < 0.001) than the non-athletic healthy males. This study demonstrates the ability of the Yo-Yo IR1 to discriminate endurance performance between elite and sub-elite AF players, whilst further distinguishing AF players from a non-athletic healthy control group.

Effects of aerobic training on the exercise-induced decline in short-passing ability in junior soccer players

To examine the effects of aerobic interval training on the decline in short-passing ability caused by a short bout of high-intensity intermittent activities. For this randomized controlled trial, 26 junior soccer players (mean age, 17.8 +/- 0.6 years; mean height, 178 +/- 5 cm; mean body mass, 74.5 +/- 6.9 kg) were recruited. After baseline measurements, subjects were randomly allocated to 1 of 2 groups: the control group (CG) or the aerobic interval training group (ITG). The ITG completed 4 weeks of high-intensity aerobic training, consisting of 4 bouts of running for 4 min at 90%-95% of maximal heart rate, with 3 min of active recovery between sets, in addition to normal training. Maximum oxygen uptake, Yo-Yo Intermittent Recovery Test level 1 (YYIRT), and short-passing ability (measured using the Loughborough Soccer Passing Test (LSPT)) were measured before and after a 5 min high-intensity simulation (HIS), reproducing the most intense phase of a match. The ITG (n = 11), but not the CG (n = 10), showed a significant 12% and 4% increase in YYIRT and maximal oxygen consumption after training, respectively, and reduced the worsening in LSPT penalty time after the HIS (p < 0.05). The relative exercise intensity during HIS decreased in the ITG only (p < 0.01). Our results demonstrated that junior soccer players may benefit from aerobic training to attenuate the decline in short-passing ability caused by a short bout of intermittent activities completed at the same pretraining workload.

A Test to Evaluate the Physical Impact on Technical Performance in Soccer

The aim of the study was to develop and examine a test for evaluation of the physical and technical capacity of soccer players. Fourteen youth elite (YE) and seven sub-elite (SE) players performed a physical and technical test (PT-test) consisting of 10 long kicks interspersed with intense intermittent exercise. In addition, a control test (CON-test) without intense exercise was performed. In both cases, the test result was evaluated by the precision of the 10 kicks. The players also performed the Yo-Yo intermittent recovery test level 2 (Yo-Yo IR2). For the SE-players, blood samples were obtained and heart rate was measured before, during, and after the PT-test. A muscle biopsy was collected before and after the PT-test. Coefficient of variation for the PT- and CON-test was 11.7% and 16.0%, respectively. The YE-players performed better (P < 0.05) than the SE-players in both the PT-test (16.3 +/- 0.8 (+/-SE) vs. 13.2 +/- 1.3 points) and CON-test (24.4 +/- 0.7 vs. 20.5 +/- 1.6 points) with no difference in the relative PT-test result (PT-test/CON-test: 0.63 +/- 0.03 vs. 0.64 +/- 0.03). Summed performance of the first 5 repetitions was higher (P < 0.05) than for the last 5 repetitions (8.4 +/- 0.6 vs. 6.9 +/- 0.5; n = 20). The YE-players performed better (P < 0.05) than the SE-players during Yo-Yo IR2 (1023 +/- SE vs. 893 +/- SE m). The mean heart rate during the PT-test was 173 +/- 4 b.p.m. (90 +/- 2% of HRmax). Blood lactate, glucose, and ammonia reached 5.6 +/- 0.7, 6.2 +/- 0.6 mmol L(-1), and 76 +/- 11 umol L(-1) at the end of the test, respectively. After the test muscle CP, glycogen and lactate was 52.9 +/- 6.6, 354 +/- 39, and 25.3 +/- 5.9 mmol kg(-1) d.w., respectively. In summary, the PT-test can be used to evaluate a soccer player's technical skills under conditions similar to intense periods of a soccer game.

The Yo–Yo intermittent recovery test in basketball players

The purpose of this study was to examine the physiological correlates of the Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1) in basketball players. Twenty-two male basketball players (means+/-S.D., body mass 72.4+/-11.4kg, height 181.7+/-6.9cm, age 16.8+/-2.0 years) were tested for maximal oxygen uptake (VO(2max)), ventilatory threshold (VT) and running economy (RE) on a motorized treadmill. Lower limb explosive strength and anaerobic-capacity was assessed using vertical jumps (CMJ), 15m shuttle running sprint (15mSR) and line drill (LD), respectively. The same test battery was replicated after an experimental basketball game in order to assess selective effect of fatigue on physical performance. Pre to post-game CMJ (40.3+/-5.7 versus 39.9+/-5.9cm) and 15mSR (5.80+/-0.25 versus 5.77+/-0.22s) performances were not significantly different (p>0.05). LD performance decreased significantly post-game (from 26.7+/-1.3 to 27.7+/-2.7s, p<0.001). Yo-Yo IR1 performances (m) were significantly related to VO(2max) (r=0.77, p=0.0001), speed at VO(2max) (r=0.71, p=0.0001) and %VO(2max) at VT (r=-0.60, p=0.04). Yo-Yo IR1 performance was significantly correlated to post-game LD decrements (r=-0.52, p=0.02). These findings show that Yo-Yo IR1 may be considered as a valid basketball-specific test for the assessment of aerobic fitness and game-related endurance.

Aerobic Fitness and Yo-yo Continuous and Intermittent Tests Performances in Soccer Players: A Correlation Study

Yo-yo tests are very popular in soccer; however, no study has addressed details of their relation to canonical aspects of aerobic fitness. Furthermore, no information is available on the effect of the individual levels of lower limbs' explosive strength on yo-yo tests in soccer players. The purpose of this study was to examine the physiological determinants of Yo-yo Endurance Test Level 2 (YYETL2) and Yo-yo Intermittent Recovery Test Level 1 (YYIRTL1) in soccer players. Twenty-four soccer players (body mass, 74.6 +/- 8.5 kg; height, 178.1 +/- 4.5 cm; age, 25.6 +/- 5.1 years) were tested for VO2max and ventilatory threshold (VT) on a motorized treadmill. Lower-limb explosive strength was assessed using vertical countermovement jumps (CMJ) performed on a force platform. Results showed that YYETL2 and YYIRTL1 performances (m) were significantly related (r = 0.75, p = 0.00002). YYETL2 results were significantly related to VO2max, VTVO2, and speed at VT (r = 0.75, 0.76, and 0.83, respectively; p < 0.00002). Peak treadmill speed results were significantly related to YYETL2 and YYIRTL1 (r = 0.87 and 0.71, respectively; p < 0.0003). YYIRTL1 was related to CMJ peak power (r = 0.57; p = 0.003). These findings show that YYETL2 and YYIRTL1, although adopting similar starting and progression speeds, are influenced by different physiological variables. From these results, YYETL2 can be considered an aerobic fitness-related field test, whereas YYIRTL1 can be regarded as an aerobic-anaerobic, soccer-specific field test.

Pulmonary Kinetics Of Oxygen Uptake And Sport Specific Fitness In Soccer Players

Elite soccer performance is, in part, dependent on a high level of cardiopulmonary fitness, which can either be assessed maximally (VO2max), or as a dynamic response to a change in work (VO2 kinetics). The kinetics of oxygen uptake (VO2) are enhanced following endurance training, and are also differentially fastest in elite endurance athletes; it is therefore surprising that VO2 kinetics have not been reported in intermittent sports such as soccer, where the ability to rapidly respond to a change in work is of importance. PURPOSE To compare laboratory (VO2 kinetics & VO2 max) and field based (Yo-Yo intermittent test) assessments of cardiopulmonary fitness in professional and amateur soccer players. METHODS A group of professional (Pro) (n = 18) and amateur (Am) (n = 18) soccer players agreed to participate in the study. Both groups performed 3 tests: 1) a graded exercise test to exhaustion for the determination of VO2 max 2) four repeats of a single exercise transient from walking to 80%Δ (80% of the difference between Tvent and VO2 max) for the assessment of VO2 kinetics, and 3) a soccer specific test (Yo-Yo Intermittent Recovery Test level 2). Gas exchange was measured breath-by-breath and a two component exponential model was used to characterise the kinetics of the VO2 response. Statistical analyses were made using ANOVA and ‘t’ tests as appropriate. RESULTS There was no difference in the cardiopulmonary fitness of the professional and amateur players when expressed as VO2 max (Pro 56.5 ± 2.9ml.kg·min−1 vs Am 55.7 ± 3.5ml.kg·min−1) or the VO2 kinetic fundamental (τ1 onset, Pro 24.5±3.2 s vs Am 24.0±1.8 s; τ1 offset, Pro 28.7±2.8 s vs Am 29.3±3.5 s) and slow components (τ2 onset, Pro 98.2±56.6 s vs Am 142.2±58.6 s; τ2 offset, Pro 261.1±60.7 s vs 277.8±71.7 s). However, professionals (966 ± 153m) achieved a greater total distance covered than amateurs (840 ± 156m) in the Yo-Yo test (p < 0.05). CONCLUSION The intermittent demands of soccer make the determination of specific fitness difficult to quantify. Nevertheless, the findings of this study suggest that sport specific assessment has greater relevance to the identification of fitness in performers participating at different levels of the sport. Whilst cardiopulmonary fitness is important for soccer performance, the ability to rapidly respond to a change in work rate does not contribute to the difference in soccer specific performance observed between the professional and amateur players. Other factors, such as anaerobic fitness, may be of more importance.