Reliability of a Repeated High-Intensity Effort Test for Elite Rugby Union Players

Effects of Repeated High-Intensity Effort Training or Repeated Sprint Training on Repeated High-Intensity Effort Ability and In-Game Performance in Professional Rugby Union Players

ABSTRACT

Glaise, P, Rogowski, I, and Martin, C. Effects of repeated high-intensity effort training or repeated sprint training on repeated high-intensity effort ability and in-game performance in professional rugby union players. J Strength Cond Res 38(5): 932-940, 2024-This study investigated the effects of repeated high-intensity efforts (RHIE) training compared with repeated sprint exercise (RSE) training on RHIE ability (RHIEa) and in-game performance in professional rugby union players. Thirty-nine, male, professional, rugby union players were randomly assigned to 3 training groups (RHIE training, RSE training, and control). Repeated high-intensity effort ability and high-intensity effort characteristics (including sprints, acceleration, and contact efforts) during official games were measured before and after a 10-week specific (RHIE, RSE, or control) training period. The results of this study showed that concerning RHIEa, both the RHIE and RSE training significantly increased the players' average sprint velocity ( p < 0.001, d = -0.39 and p < 0.001, d = -0.53 respectively), average sled push velocity (ASPV; p < 0.001, d = -0.81 and p = 0.017, d = -0.48 respectively), and RHIE score ( p < 0.001, d = -0.72 and p < 0.001, d = -0.60 respectively). Repeated high-intensity effort training trended in a smaller increase in average sprint velocity than RSE training, a larger increase in ASPV, and a similar increase in RHIE score. Concerning in-game high-intensity efforts, both the RHIE and RSE training produced significant improvements in the number of sprints ( p = 0.047, d = -0.28 and p < 0.001, d = -0.47 respectively), total distance ( p < 0.001, d = -0.50 and p = 0.002, d = -0.38 respectively), the number of accelerations ( p < 0.001, d = -0.37 and p = 0.003, d = -0.32 respectively), and contact rate ( p < 0.001, d = -0.97 and p = 0.020, d = -0.28 respectively). Conversely, the magnitude of the increase in contact rate was almost twice as high in RHIE compared with RSE training. To conclude, the findings of this study were that both RSE and RHIE training are effective methods for developing RHIEa and in-game high-intensity efforts in professional rugby union. In practical applications, as the gains in certain abilities and game performance data differed depending on the training method chosen, we suggest that coaches choose the most appropriate method according to the profile of the players, their position, and the style of play they want to develop.

Preconditioning Activities to Enhance Repeated High-Intensity Efforts in Elite Rugby Union Players

PURPOSE

To assess the effect of a rugby-specific high-intensity interval-training (HIITRugby) protocol on the repeated high-intensity-effort ability of young elite rugby union players and to verify the influence of 2 preconditioning sequences composed either of physical contacts (ie, tackles) or of additional runs on the magnitude of improvement.

METHOD

Fourteen players (19 [1] y; 183.5 [8.6] cm; 95.6 [15.6] kg) underwent an HIITRugby protocol, consisting of 7 supervised training sessions over 4 weeks, each session including 3 or 4 sets of 1 to 2 minutes with 1-minute recovery. Prior to HIITRugby training, players underwent a preconditioning contact sequence or a preconditioning running sequence, to assess their influence on subsequent interval-training sessions.

RESULTS

The overall group showed a moderate improvement in total sprint time, sprints ≥90% of the best, and 20-m sprint (-3.91% [2.68%], P = .0002; 74.6% [123.7%], P = .012; -3.22% [3.13%], P = .003, respectively) and a large improvement in percentage decrement (-23.1% [20.5%], P = .005) following the 4-week training block. Relative improvements were similar between groups in total sprint time, 20-m sprint, and perceived difficulty, but the preconditioning running-sequence group exhibited a larger magnitude of gains in percentage decrement (-28.6% [20.2%] vs -17.6% [20.7%]; effect size = -1.01 vs -0.73).

CONCLUSION

An HIITRugby training block was effective to improve repeated high-intensity-effort ability. A preconditioning contact sequence prior to HIITRugby can reduce subsequent long-interval running activity, which may attenuate the improvement of repeated high-intensity-effort indices related to the aerobic system.

Data repeatability for the Cosmed K4 b2 portable metabolic cart during non-steady state exercise

BACKGROUND: Portable metabolic carts are a popular tool to assess aerobic capacity and affirm many cardiorespiratory conditions. They may also measure strength training performance. Given their popularity and increased usage to assess strength training performance; their data accuracy and consistency are important to determine. OBJECTIVE: Measure Cosmed K4 b2 portable metabolic cart data repeatability from consecutive seated calf press workouts. METHODS: Fifteen women and twelve men did two workouts that began with a stationary cycling warm-up followed by calf presses. Gases were measured before the calf press portion of workouts to establish baseline VO2 and VCO2 values, as well as continually throughout and after the calf press protocol. Subjects were detached from the cart once gas values returned to baseline after workouts concluded. In addition to VO2 and VCO2, repeatability was quantified for: breaths per minute, tidal volume, ventilation, O2 uptake relative to body mass, expired O2 and CO2 fractions, percent fat and carbohydrate utilization, METS and total energy cost. Mean and peak values per variable were analyzed. Repeatability was assessed separately for male and female data, as well as with values pooled, by the following: intraclass correlation coefficients, eta squared, limits of agreement, coefficient of variation and smallest real difference percent. RESULTS: Per variable, repeatability values across workouts were low. Female intraclass correlation coefficient mean values were more repeatable for variables related to gas measurements, yet male data were generally more repeatable for those related to substrate usage. CONCLUSIONS: Results for some repeatability indices were influenced by measurement magnitude. Peak values were predictably less repeatable than those for mean values. Most smallest real differences percent scores are so high they were rendered irrelevant or meaningless to determine true differences among paired values. Results suggest low data repeatability that are likely appropriate and realistic for the exercise protocol, hardware and intensity examined.

Fitness Determinants of Repeated High-Intensity Effort Ability in Elite Rugby Union Players

PURPOSE

To investigate the relationship between physical fitness and repeated high-intensity effort (RHIE) ability in elite rugby union players, depending on playing position.

METHOD

Thirty-nine players underwent a fitness testing battery composed of a body composition assessment, upper-body strength (1-repetition maximum bench press and 1-repetition maximum bench row), lower-body strength (6-repetition maximum back squat), and power (countermovement jump, countermovement jump with arms, and 20-m sprint), as well as aerobic fitness (Bronco test) and RHIE tests over a 1-week period. Pearson linear correlations were used to quantify relationships between fitness tests and the RHIE performance outcomes (total sprint time [TST] and percentage decrement [%D]). Thereafter, a stepwise multiple regression model was used to verify the influence of physical fitness measures on RHIE ability.

RESULTS

TST was strongly to very strongly associated to body fat (BF, r = .82, P < .01), the 20-m sprint (r = .86, P < .01), countermovement jump (r = -.72, P < .01), and Bronco test (r = .90, P < .01). These fitness outcomes were related to %D, with moderate to strong associations (.82 > ∣r∣ > .54, P < .01). By playing position, similar associations were observed in forwards, but RHIE ability was only related to the 20-m sprint in backs (r = .53, P < .05). The RHIE performance model equations were TST = 13.69 + 0.01 × BF + 0.08 × Bronco + 10.20 × 20 m and %D = -14.34 + 0.11 × BF +0.18 × Bronco - 9.92 × 20 m. These models explain 88.8% and 68.2% of the variance, respectively.

CONCLUSION

Body composition, lower-body power, and aerobic fitness were highly related with RHIE ability. However, backs expressed a different profile than forwards, suggesting that further research with larger sample sizes is needed to better understand the fitness determinants of backs' RHIE ability.

Tapering and Repeated High-Intensity Effort Ability in Young Elite Rugby Union Players: Influence of Pretaper Fatigue Level

PURPOSE

To assess the effects of a short-term taper on the ability to perform repeated high-intensity efforts, depending on players' fatigue level following an intensive training block.

METHOD

After a 3-day off-season camp, 13 players followed the same 3-week preseason training block followed by a 7-day exponential taper. Performance was assessed by a repeated high-intensity effort test before and after the taper. Total sprint time, percentage of decrement, and the number of sprints equal to or higher than 90% of the best sprint were retained for analysis. Players were a posteriori classified in normal training or acute fatigue groups based on their readiness to perform prior to the taper, assessed through the magnitude of difference in psychological (Profile of Mood State Questionnaire), cardiovascular (submaximal constant-duration cycling), and neuromuscular (countermovement jump) tests between the preintensive and postintensive training blocks.

RESULTS

Training load declined by 55% (9%) during the taper (P = .001, g = -2.54). The overall group showed a small improvement in total sprint time (-3.40% [3.90%], P = .04, g = -0.39) following the taper. Relative changes tended to be higher in the acute fatigue compared with the normal training group (-5.07% [4.52%] vs -1.45% [1.88%], respectively; P = .08; d = 1.01). No taper-induced improvement was observed in percentage of decrement or number of sprints equal to or higher than 90% of the best sprint.

CONCLUSION

A 7-day taper consisting of 55% training load reduction improved repeated high-intensity effort performance in young elite rugby union players. Pretaper level of fatigue seems to be a key determinant in the taper supercompensation process, as acutely fatigued players at the end of the intensive training block tended to benefit more from the taper.