Supplementing regular training with short-duration sprint-agility training leads to a substantial increase in repeated sprint-agility performance with national level badminton players

Correlation Between Heart Rate Variability and Agility Scores of Elite Badminton Players: A Pilot Study

Introduction Heart rate variability (HRV) indexes the autonomic nervous system, and HRV values are found to be higher in elite badminton players. Since an athlete's agility has a direct influence on badminton sporting performance, this study will analyze the correlation between HRV and agility. Aim The study's primary aim is to analyze the correlation between HRV and agility scores of elite badminton players. Methodology Ten elite badminton players who are currently participating at the state and national levels were recruited for the study. The study's participants were aged between 18 and 21 years, had a body mass index (BMI) of less than 22.9 kg/m2, were currently training 10-12 sessions of badminton per week (120-180 minutes per session), and had no comorbidities, injuries, or illnesses. For a duration of 14 days, a cross-sectional study design was utilized to evaluate the badminton players. Participants were tested in two blocks; each block consisted of five days of HRV and agility testing (Southeast Missouri [SEMO] agility test) followed by a break for two days. Higher agility performance was reflected by a lower SEMO agility test score. Results Data were analyzed using IBM SPSS Statistics for Windows, Version 27.0 (IBM Corp., Armonk, NY). HRV and agility scores had a negative correlation, as indicated by the two-tailed Spearman correlation analysis (rs(8) = -0.82, P < 0.01). Conclusions The results showed that HRV and agility scores are highly correlated in elite badminton players. The results indicate that higher HRV values lead to better agility performance. Future studies need to be conducted on a large scale to evaluate the correlation in a diverse population.

The impact of verbal encouragement during the repeated agility speed training on internal intensity, mood state, and physical enjoyment in youth soccer players

Objective

Verbal encouragement (VE) can be used by coaches to boost morale and commitment during training exercises. This investigation aimed to study the impacts of VE given by coaches on the physiological aspects, players' internal intensity, mood, and perceived enjoyment of youth soccer players during repeated agility speed training (RAS).

Methods

A total of 17 male youth soccer players (mean ± SD; age: 13.8 ± 0.4 years; body mass: 59.1 ± 6.7 kg; height: 170.0 ± 6.2 cm; training experience: 5.1 ± 0.7 years) participated, in a randomized order, in two experimental training sessions that consisted of a RAS (i.e., the Illinois course) either with VE (RAS-E) or without VE (RAS-NE), with a 7-day interval between the testing sessions. Heart rate (HR) was registered throughout the exercise. The rating of perceived exertion, blood lactate concentration [La], and perceived enjoyment were measured after each training session. The mood state was recorded before and after each protocol.

Results

HR mean (Cohen's coefficient d = 0.45, small), %HRmax (d = 0.37, small), HR peak (d = 0.66, moderate), [La] (d = 0.56, small), and the PACES score (d = 2.8, very large) were higher in RAS-E compared to RAS-NE (all, P < 0.001). Compared to the RAS-E trial, the RAS-NE trial showed higher fatigue (P < 0.01), tension (P < 0.05), anger (0.05), total mood score (P < 0.001), and lower vigor (P < 0.001).

Conclusion

Coaches may use VE during RAS to improve psychophysiological responses, mood state, and perceived enjoyment in youth soccer players.

Exercise-Induced Fatigue Impairs Change of Direction Performance and Serve Precision among Young Male Tennis Players

This study investigates the effect of exercise-induced fatigue on change of direction performance and serve precision among young tennis players. A group of 21 players (age 12.90 ± 0.76 years), ranked among the top 50 players on the national tennis federation scale and the top 300 on the "Tennis Europe" scale, participated in the study. They underwent a standardized physiological load protocol using the "300-m running test" which consists of consecutive runs for 15 shares of 20 m (15 × 20). Its intensity was determined using the Borg Rating of Perceived Exertion (RPE) scale where subjects evaluated their level of experienced load on a scale from 0 to 10. Prior to and after the protocol, they performed a pre-planned change of direction T-test and serve precision test. Results showed significant increase of time in the T-test (from 11.75 ± 0.45 s to 12.99 ± 0.4 s, p = 0.00) and decrease in serve precision parameter from (6.00 ± 1.04 to 4.00 ± 1.26, p = 0.00) after the fatigue test protocol. The RPE increased from 5 to 9, after the fatigue protocol, indicating the desired fatigue effect. These findings indicate that exercise-induced fatigue impairs change of direction performance and serve precision among young tennis players.

Progressive decrease in leg-power performance during a fatiguing badminton field test

[Purpose] This study aimed to evaluate the changes in leg-power generation that accompany competitive badminton, as simulated in a badminton field test (FT). [Participants and Methods] Fifteen male badminton players with 1–2 years of experience performed five repetitions of an FT involving rapid and randomly assigned shuttle-run movements between markers distributed around a badminton court. Repetitions were separated by a 1-minute rest period. Peak mechanical power, obtained from the serial vertical jump tests, was used to estimate fatigue and performance reduction. [Results] Decreases in distance and time were significantly different in each of the five FT repetitions while maintaining the same speed for the condition. The peak mechanical power and fatigue index significantly declined. The reduction in the peak mechanical power percentage (11.78–35.49%) was in the acceptable peak mechanical power range for each FT set. These results were confirmed by the significant increase in the participants’ blood lactate concentration levels, the rating of perceived exertion, and heart rate. [Conclusion] Leg-power generation could gradually be decreased in badminton competition as indicated by a badminton field test.

Should agility training for novice badminton players be physically or perceptually challenging?

BACKGROUND

Despite its well-known importance in sports, agility is ambiguously defined and lack of research. Shuttle Run (SR) challenges physical quickness and is commonly used to improve the on-court agility of badminton players. In contrast, Reactive Initiation Training (RIT) challenges perceptual quickness, merely demanding rapid initiation of step toward the direction of shuttlecock.

METHODS

The current study explores to compare SR with RIT to determine the relative effectiveness of these training on improving the on-court agility of badminton. 20 novice badminton players were split in half to receive either RIT or SR on court for five days. Before and after training, the on-court agility test with and without anticipation was administered.

RESULTS

The results showed that both training methods shortened the mean running time, however, only RIT additionally reduced the initiation time and its proportion on those time-consuming positions when agility was assessed without anticipation.

CONCLUSIONS

Therefore, the agility training for novice badminton players should be more perceptually than physically challenging to avoid vain effort and unnecessary injuries.

Evaluating Injury Risk and Gender Performance on Health- and Skill-Related Fitness Assessments

Grier, TL, Canham-Chervak, M, Bushman, TT, Anderson, MK, North, WJ, and Jones, BH. Evaluating injury risk and gender performance on health- and skill-related fitness assessments. J Strength Cond Res 31(4): 971-980, 2017-The purpose of this analysis was to investigate the association of injury risk and gender performance on health- and skill-related fitness assessments. A survey was used to collect personal characteristics and Army Physical Fitness Test scores (2-mile run, push-ups, and sit-ups). Within the same day, 9 physical fitness assessments were performed. Percent body fat was estimated using height, weight, age, and sex. All fitness assessment data were categorized into tertiles of high, moderate and low performance. To investigate potential injury risk predicted by fitness assessment performance, injury risk ratios, odds ratios (ORs), and 95% confidence intervals (CIs) were calculated using medical record data. A total of 3,264 soldiers completed surveys and physical fitness assessments. Tertiles of fitness performance with men and women combined showed that on an average, 14% of women and 70% of men were in the moderate- and high-performance groups. Among men, higher injury risk was independently associated with low performance on a 2-mile run (ORslow/fast = 1.51, 95% CI 1.18-1.94) and low performance on a weighted 300-yard shuttle run (ORslow/fast = 1.36, 95% CI 1.06-1.74). For women, a higher risk of injury was associated with low performance on the 2-mile run (ORslow/fast = 2.38, 95% CI 1.04-5.74). Therefore, out of the 13 fitness assessments, the 2-mile run and weighted 300-yard shuttle run can also (in addition to measuring performance) be utilized to identify soldiers or athletes who are at a higher risk of experiencing an injury.

A review of the physiological and psychological health and wellbeing of naval service personnel and the modalities used for monitoring

Naval cohorts rely heavily on personnel to ensure the efficient running of naval organisations. As such, the wellbeing of personnel is essential. In an occupational setting, naval service personnel experience a variety of physiological and psychological stressors. Most naval services arrange annual physical fitness and body composition tests to ensure the physical readiness of personnel. However, these tests only evaluate a small amount of physiological capabilities. Components such as aerobic and strength capabilities are assessed, however, other components of physical fitness such as speed, agility, anaerobic capacity and flexibility are not. In addition to the physical capabilities, personnel are impacted by fatigue, nutrition and psychological stressors such as copping in stressful situations or dealing with time away from family and friends. This review will discuss the physiological and psychological factors that affect personnel's wellbeing. In addition to this, it will also evaluate the methods that are used to assess both physiological and psychological wellbeing.

Testing of Badminton-Specific Endurance

Madsen, CM, Højlyng, M, and Nybo, L. Testing of badminton-specific endurance. J Strength Cond Res 30(9): 2582-2590, 2016-In the present study, a novel intermittent badminton endurance (B-ENDURANCE) test was developed and tested in elite (n = 17) and skilled (n = 9) badminton players and in age-matched physically active men (nonbadminton players; n = 8). In addition, B-ENDURANCE test-retest reproducibility was evaluated in 9 badminton players. The B-ENDURANCE test is an incremental test where each level consists of repeated sequences of badminton-specific actions toward the 4 corners of the court. The subject starts in the center of the court in front of a computer screen and within each sequence, he must, in a randomized order, complete 8 actions as dictated by the computer, providing the audiovisual input and verifying that the appropriate sensor is activated within the allocated time. Recovery time between each sequence is 10 seconds throughout the test, but the time to complete each sequence is gradually decreased until the subjects cannot follow the dictated tempo. The B-ENDURANCE test performance for elite players was better (p ≤ 0.05) compared with the skilled players and nonbadminton players. In addition, the B-ENDURANCE test performance correlated (r = 0.8 and p < 0.0001) with elite players' national single rankings. Test-retest coefficient of variation was 7.9% between the first 2 trials (i.e., without a familiarization trial) but reduced to 2.5% when comparing the second and third trials. In conclusion, the B-ENDURANCE test is relevant for the evaluation of badminton-specific endurance but at least 1 familiarization trial is recommended if the test is used for evaluation of longitudinal changes, e.g., tracking training effects.

Effects of additional repeated sprint training during preseason on performance, heart rate variability, and stress symptoms in futsal players: a randomized controlled trial

The aim of this study was to investigate whether supplementing regular preseason futsal training with weekly sessions of repeated sprints (RS) training would have positive effects on repeated sprint ability (RSA) and field test performance. Thirteen players from a professional futsal team (22.6 ± 6.7 years, 72.8 ± 8.7 kg, 173.2 ± 6.2 cm) were divided randomly into 2 groups (AddT: n = 6 and normal training group: n = 7). Both groups performed a RSA test, Yo-Yo intermittent recovery test level 1 (YoYo IR1), squat (SJ) and countermovement jumps (CMJ), body composition, and heart rate variability (HRV) measures at rest before and after 4 weeks of preseason training. Athletes weekly stress symptoms were recorded by psychometric responses using the Daily Analysis of Life Demands for Athletes questionnaire and subjective ratings of well-being scale, respectively. The daily training load (arbitrary units) was assessed using the session of rating perceived exertion method. After the preseason training, there were no significant changes for body composition, SJ, CMJ, and RSAbest. The YoYo IR1, RSAmean, RSAworst, and RSAdecreament were significantly improved for both groups (p ≤ 0.05). The HRV parameters improved significantly within both groups (p ≤ 0.05) except for high frequency (HF, absolute and normalized units, [n.u.]), low frequency (LF) (n.u.), and the LF/HF ratio. A moderate effect size for the AddT group was observed for resting heart rate and several HRV measures. Training load and psychometric responses were similar between both groups. Additional RS training resulted in slightly greater positive changes for vagal-related HRV with similar improvements in performance and training stress during the preseason training in futsal players.

The Effect of Two Speed Endurance Training Regimes on Performance of Soccer Players

In order to better understand the specificity of training adaptations, we compared the effects of two different anaerobic training regimes on various types of soccer-related exercise performances. During the last 3 weeks of the competitive season, thirteen young male professional soccer players (age 18.5±1 yr, height 179.5±6.5 cm, body mass 74.3±6.5 kg) reduced the training volume by ~20% and replaced their habitual fitness conditioning work with either speed endurance production (SEP; n = 6) or speed endurance maintenance (SEM; n = 7) training, three times per wk. SEP training consisted of 6–8 reps of 20-s all-out running bouts followed by 2 min of passive recovery, whereas SEM training was characterized by 6–8 x 20-s all-out efforts interspersed with 40 s of passive recovery. SEP training reduced (p<0.01) the total time in a repeated sprint ability test (RSA_t) by 2.5%. SEM training improved the 200-m sprint performance (from 26.59±0.70 to 26.02±0.62 s, p<0.01) and had a likely beneficial impact on the percentage decrement score of the RSA test (from 4.07±1.28 to 3.55±1.01%) but induced a very likely impairment in RSA_t (from 83.81±2.37 to 84.65±2.27 s). The distance covered in the Yo-Yo Intermittent Recovery test level 2 was 10.1% (p<0.001) and 3.8% (p<0.05) higher after SEP and SEM training, respectively, with possibly greater improvements following SEP compared to SEM. No differences were observed in the 20- and 40-m sprint performances. In conclusion, these two training strategies target different determinants of soccer-related physical performance. SEP improved repeated sprint and high-intensity intermittent exercise performance, whereas SEM increased muscles’ ability to maximize fatigue tolerance and maintain speed development during both repeated all-out and continuous short-duration maximal exercises. These results provide new insight into the precise nature of a stimulus necessary to improve specific types of athletic performance in trained young soccer players.

Repeated-sprint and change-of-direction abilities in physically active individuals and soccer players: training and testing implications

The relationship between repeated-sprint ability (RSA) and repeated change-of-direction (RCOD) matched on intervals and distances was investigated in this study. The discrimination abilities of the tests were also examined. Using a within-subject repeated measures design, 25 physically active individuals (ACTs), 16 college soccer players (COL), and 18 professional soccer players (PRO) performed the RSA and RCOD tests during which the fastest time (FT), average time (AT), total time (TT), and percentage decrement score (%Dec) were recorded. We concluded that RSA and RCOD tested separate motor abilities because the shared variance between them in the FT, AT, and TT was ≤50%. Both RSA and RCOD tests were reliable (intraclass correlation coefficient ranged 0.79-0.90) and valid performance assessments in terms of construct in that they discriminated between ACT and soccer players (irrespective of the soccer skill level in this study). Specifically, the FT, AT, and TT (but not %Dec) of RSA and RCOD were significantly higher in ACT as compared with that in both COL and PRO (p < 0.05). Most values of the RSA/RCOD index in COL and PRO were 0.59, which were significantly higher than those of ACT (0.53, p < 0.05). We proposed the use of the RSA/RCOD index with a target value of 0.59 to prioritize and quantify the training needs of RSA and RCOD for soccer players.

Repeated-sprint ability - part II: recommendations for training

Short-duration sprints, interspersed with brief recoveries, are common during most team sports. The ability to produce the best possible average sprint performance over a series of sprints (≤10 seconds), separated by short (≤60 seconds) recovery periods has been termed repeated-sprint ability (RSA). RSA is therefore an important fitness requirement of team-sport athletes, and it is important to better understand training strategies that can improve this fitness component. Surprisingly, however, there has been little research about the best training methods to improve RSA. In the absence of strong scientific evidence, two principal training theories have emerged. One is based on the concept of training specificity and maintains that the best way to train RSA is to perform repeated sprints. The second proposes that training interventions that target the main factors limiting RSA may be a more effective approach. The aim of this review (Part II) is to critically analyse training strategies to improve both RSA and the underlying factors responsible for fatigue during repeated sprints (see Part I of the preceding companion article). This review has highlighted that there is not one type of training that can be recommended to best improve RSA and all of the factors believed to be responsible for performance decrements during repeated-sprint tasks. This is not surprising, as RSA is a complex fitness component that depends on both metabolic (e.g. oxidative capacity, phosphocreatine recovery and H+ buffering) and neural factors (e.g. muscle activation and recruitment strategies) among others. While different training strategies can be used in order to improve each of these potential limiting factors, and in turn RSA, two key recommendations emerge from this review; it is important to include (i) some training to improve single-sprint performance (e.g. 'traditional' sprint training and strength/power training); and (ii) some high-intensity (80-90% maximal oxygen consumption) interval training to best improve the ability to recover between sprints. Further research is required to establish whether it is best to develop these qualities separately, or whether they can be developed concurrently (without interference effects). While research has identified a correlation between RSA and total sprint distance during soccer, future studies need to address whether training-induced changes in RSA also produce changes in match physical performance.