A Systematic Review and Meta-analysis of the Association Between ACTN3 R577X Genotypes and Performance in Endurance Versus Power Athletes and Non-athletes

BACKGROUND

Previous studies reported differences in genotype frequency of the ACTN3 R577X polymorphisms (rs1815739; RR, RX and XX) in athletes and non-athletic populations. This systematic review with meta-analysis assessed ACTN3 R577X genotype frequencies in power versus endurance athletes and non-athletes.

METHODS

Five electronic databases (PubMed, Web of Science, Scopus, Science Direct, SPORTDiscus) were searched for research articles published until December 31st, 2022. Studies were included if they reported the frequency of the ACTN3 R577X genotypes in power athletes (e.g., weightlifters) and if they included a comparison with endurance athletes (e.g., long-distance runners) or non-athletic controls. A meta-analysis was then performed using either fixed or random-effects models. Pooled odds ratios (OR) were determined. Heterogeneity was detected using I2 and Cochran's Q tests. Publication bias and sensitivity analysis tests were computed.

RESULTS

After screening 476 initial registrations, 25 studies were included in the final analysis (13 different countries; 14,541 participants). In power athletes, the RX genotype was predominant over the two other genotypes: RR versus RX (OR 0.70; 95% CI 0.57-0.85, p = 0.0005), RR versus XX (OR 4.26; 95% CI 3.19-5.69, p < 0.00001), RX versus XX (OR 6.58; 95% CI 5.66-7.67, p < 0.00001). The R allele was higher than the X allele (OR 2.87; 95% CI 2.35-3.50, p < 0.00001) in power athletes. Additionally, the frequency of the RR genotype was higher in power athletes than in non-athletes (OR 1.48; 95% CI 1.25-1.75, p < 0.00001). The RX genotype was similar in both groups (OR 0.84; 95% CI 0.71-1.00, p = 0.06). The XX genotype was lower in power athletes than in controls (OR 0.73; 95% CI 0.64-0.84, p < 0.00001). Furthermore, the R allele frequency was higher in power athletes than in controls (OR 1.28; 95% CI 1.19-1.38, p < 0.00001). Conversely, a higher frequency of X allele was observed in the control group compared to power athletes (OR 0.78; 95% CI 0.73-0.84, p < 0.00001). On the other hand, the frequency of the RR genotype was higher in power athletes than in endurance athletes (OR 1.27; 95% CI 1.09-1.49, p = 0.003). The frequency of the RX genotype was similar in both groups (OR 1.07; 95% CI 0.93-1.24, p = 0.36). In contrast, the frequency of the XX genotype was lower in power athletes than in endurance athletes (OR 0.63; 95% CI 0.52-0.76, p < 0.00001). In addition, the R allele was higher in power athletes than in endurance athletes (OR 1.32; 95% CI 1.11-1.57, p = 0.002). However, the X allele was higher in endurance athletes compared to power athletes (OR 0.76; 95% CI 0.64-0.90, p = 0.002). Finally, the genotypic and allelic frequency of ACTN3 genes were similar in male and female power athletes.

CONCLUSIONS

The pattern of the frequencies of the ACTN3 R577X genotypes in power athletes was RX > RR > XX. However, the RR genotype and R allele were overrepresented in power athletes compared to non-athletes and endurance athletes. These data suggest that the RR genotype and R allele, which is associated with a normal expression of α-actinin-3 in fast-twitch muscle fibers, may offer some benefit in improving performance development in muscle strength and power.

The meaning of injury to the elite athlete: A systematic review

In the pursuit of a successful career in elite sports, athletes mostly rely on their physical abilities. An injury can threaten such a career, thereby representing a potentially critical life event that carries considerable meaning to the affected athlete. Qualitative literature exploring injury experiences in elite athletes is therefore seeking to frame injury through the athlete's own voice. With this systematic review, we aimed to answer the research question What is the meaning of injuries to the elite athlete? by reviewing existing qualitative research exploring the meaning of injury as told from the athlete's perspective. We constructed five overarching themes of meaning through thematic synthesis of 29 original studies: (1) unwelcome disruption - Injury as potential career threat; (2) destruction - My life (as an athlete) is over; (3) reinforcement - Relighting the fire; (4) going through the motions - Injury as an inherent part of elite sport; and (5) time-out - Respite and perspective. These meanings were neither exclusive nor static but constructed according to the situation at the moment of injury and could later be adapted depending on social context and specific circumstances. To better support injured athletes, practitioners need to be aware of the importance of the subjective meaning that athletes construct for individual injuries. Understanding these meanings enables practitioners to aid athletes in changing previously negative meanings into more positive ones. Our findings therefore call for improvements in the individualized support of elite athletes that leaves space for open communication about the meanings that athletes attach to their injury experiences.

Technical and tactical evolution of the offensive team sequences in LaLiga between 2008 and 2021. Is Spanish football now a more associative game?

The aim of this investigation was to study the technical and tactical evolution of the offensive team sequences in the Spanish football teams from 2008/09 to 2020/21. A comparative analysis including twelve variables related to the development of offensive sequences in 4940 matches was performed from 2008/09 to 2020/21 seasons of the Spanish professional football league (LaLiga). All match observations were recorded using a validated video tracking system. Multilevel linear mixed models were used to examine the differences across seasons, considering the effects of contextual variables. The number of passes per sequence (2.4 [CI: 2.2-2.5] vs 3.2 [CI: 3.0-3.4]; +33.3%), the passing accuracy (72.1 [CI: 70.6-73.5] vs 76.9 [CI: 75.4-78.3]%; +6.8%) and the average duration of the team sequences (6.4 [CI: 5.9-6.8] vs 8.3 [CI: 7.8-8.7] seconds; +25.76%) showed a small increasing trend over the seasons (P < 0.05). In contrast, variables such as the direct speed of progression (2.2 [CI: 2.1-2.3] vs 1.6 [CI: 1.5-1.7] metres/second; -24.5%), key passes (8.1 [CI: 7.6-8.5] vs 6.8 [CI: 6.3-7.2]; -15.8%), and the sequences that ended in the attacking third (64.8 [CI: 62,7-66.8] vs 57.1 [CI: 55.1-59.2]; -11.7%) or in a shot (13.0 [CI: 12.4-13.6] vs 10.2 [CI: 9.6-10.8]; -21.6%) showed a small decreasing trend from 2008/09 to 2020/21 (P < 0.05). Spanish professional football teams slightly evolved technically and tactically towards a more associative style of play that includes longer passing sequences. This evolution also involved a decreasing speed of progression and fewer technical actions such as through balls, key passes and shots.

Genetic association between ADRB2 rs1042713 and elite athletic performances in the Korean population

Athletic performance is a multifactorial trait influenced by environmental and genetic factors. Previous studies have identified various genes associated with athletic performance, including the β2-adrenergic receptor (ADRB2) gene, which has been consistently shown to be linked with elite athletic performance in diverse populations. The ADRB2 gene is known to play a key role in various biological systems, including cardiovascular, pulmonary, metabolic, and musculoskeletal functions. It acts by interacting with adrenaline. In particular, the ADRB2 rs1042713 (A > G) polymorphism has been associated with cardiovascular and respiratory functions. In addition, the association between the ADRB2 rs1042713 polymorphism and athletic performance has been reported. Thus, we conducted a case-control study to analyze the genetic association with ADRB2 rs1042713 polymorphism with 150 elite athletes, 116 college athletes, and 145 controls (control I) in the Korean population. The genotypes were determined by PCR-RFLP. As a result, we found significant differences in the distributions of genotype (p = 0.005) and allele (p = 0.002) frequencies between elite athletes and the control Ⅱ (control I + college athletes). We also found that the ADRB2 rs1042713 G/G genotype [odds ratio (OR) 2.42, 95% CI 1.384-4.235, p = 0.002] and the G allele (OR 1.58, 95% CI 1.184-2.098, p = 0.002) were significantly associated with elite athletic performance. Additionally, we observed a gender-specific association in female elite athletic performance (p = 0.0002 and p = 0.0002, respectively). In conclusion, our results suggest that the ADRB2 rs1042713 polymorphism may be associated with elite athletic performance in the Korean population. To validate these findings, additional studies with larger samples, including elite athletes from various sports types and diverse ethnic origins are needed.

Predicting future stars: Probability and performance corridors for elite swimmers

OBJECTIVES

To evaluate the new age groups of the World Junior Championships in swimming from a scientific perspective, establish benchmarks and performance corridors that predict success at peak performance age and compare performance corridors between men and women and short-, middle-, and long-distance freestyle races.

DESIGN

Longitudinal big data analysis.

METHODS

In total, 347,186 annual best times of male (n = 3360, 561 ± 177 Swimming Points) and female freestyle swimmers (n = 2570, 553 ± 183 Swimming Points) were collected across all race distances at peak performance age and retrospectively analyzed throughout adolescence. Cumulative Poisson distribution was used to calculate probabilities of becoming world-class finalist, international-class, or national-class swimmer for each age group. Performance corridors were expressed relative to the World Record and compared between performance levels, sex, race distances, and age groups with a 2-way analysis of variance.

RESULTS

Females are required to swim faster relative to the World Record at a younger age and show earlier performance plateaus than males at national and international levels. Additionally, world-class long-distance finalists show higher Swimming Points earlier in their career compared to short-distance swimmers. This effect is more distinctive in females than males.

CONCLUSIONS

Based on the sex-specific performance corridors and developments, the newly aligned age groups for the World Junior Championships are questionable regarding long-term athlete development. Based on race times from 131 nations, the present benchmarks provide valid international normative values to predict success chances at peak performance age and guide young swimmers along their talent pathway.

Self-regulatory processes in goal striving during excellent distance-running performances: A qualitative study

OBJECTIVE

Goal setting can improve endurance performance, yet how endurance performers maintain goal striving and bring it to a successful close has received limited attention. In this study, we investigated the self-regulatory processes employed by long-distance runners during goal striving in excellent competitive performances.

METHOD

Through in-depth, event-focused interviews, we explored 21 long-distance runners' experiences of goal striving in excellent competitive performances (M = 77.43 h post-race). Furthermore, we recruited 10 additional participants with relevant experiences (runner n = 7, coach n = 2; sport psychologist n = 1) for external member-reflection interviews.

FINDINGS

Through our matrix analysis, we interpreted that by contrasting their current and future goal status periodically throughout their excellent performances, using a process called mental contrasting with implementation intentions (MCII), this helped the runners to make decisions about whether to persist with a goal, or disengage from a goal and reengage with an alternative. Furthermore, our findings depict how these goal decisions unfolded when runners perceived they were behind, equalling, or exceeding their goal(s). We also illustrate how goal revision was used as an adaptive process to maximise performance, and to avert or manage action crises.

CONCLUSIONS

Our findings extend theoretical understandings of goal striving and the self-regulatory processes endurance performers employ to attain and/or adapt their goals. Psychological support provided for athletes should go beyond simply setting goals, but also include training on mental frameworks such as MCII to manage goal-striving challenges and decisional conflict encountered during performances.

The Potential of Heart Rate Variability Monitoring for Mental Health Assessment in Top Wheel Gymnastics Athletes: A Single Case Design

The assessment of heart rate variability (HRV) upon waking has been proposed as a method to evaluate mental health; however, owing to large individual differences among athletes, it is unclear whether HRV is adequate to predict mental health decline. In this study, we sought to establish this by evaluating HRV upon awakening in one athlete over 20 months. We assessed mental health once a month by calculating the depression index. In addition, self-reported training load and psychological fatigue index were assessed as psychological indices for athletes. Heart rate and HRV were each measured three days per week in both resting (supine) and standing (upright) positions. The results showed that orthostatic HRV upon waking had moderate linear relationships with the scores on the depression index and psychological fatigue index. By contrast, self-reported training load, a measure of physical stressor, was not associated with HRV. The findings suggest that the repeated assessment of HRV upon waking and mental health indicators may be useful in preventing mental health decline in athletes.

VO2max (VO2peak) in elite athletes under high-intensity interval training: A meta-analysis

Consensus is lacking regarding whether high-intensity interval training (HIIT) effectively improves VO₂max (VO₂peak) in elite athletes (Athlete must be involved in regular competition at the national level). This meta-analysis compared the effects of HIIT and conventional training methods (continuous training, repeated-sprint training, high volume low-intensity training, high-intensity continuous running, sprint-interval training, moderate-intensity continuous training)on VO₂max in elite athletes. Nine studies were included, comprising 176 elite athletes (80 female). Compared to that with conventional training, VO₂max was significantly increased after HIIT (overall: 0.58 [0.30, 0.87], I² = 0.49, P = 0.03; males: 0.41 [0.06, 0.76], I² = 0%, P = 0.89). VO₂max had positive training effects when the HIIT recovery period had an interval time ≥2 min (0.44 [0.03, 0.84], I² = 0%, P = 0.99) and recovery phase intensity ≤40% (0.38 [0.05, 0.71], I² = 0%, P = 0.96). Thus, HIIT shows superiority over conventional training methods in improving VO₂max, promoting aerobic capacity, in elite athletes.

Training and competition injury epidemiology in professional basketball players: a prospective observational study

BACKGROUND

There is a lack of epidemiological data comparing the characteristics of injuries sustained during basketball matches vs. training taking into account incidence, type of injury, body location and risk factors associated with the development of the injury.

PURPOSE

The main aim of the present study was to analyze the incidence and characteristics of training vs. competition injuries sustained by professional basketball players.

METHODS

The injuries incurred by 61 professional basketball players (mean ± SD, age: 25.7 ± 5.1 years; height: 200.2 ± 9.2 cm; body mass: 98.2 ± 13.8 kg) from the same team were prospectively recorded by the team's medical staff for 6 consecutive seasons (2014/15 to 2019/20). The team competed in a top national basketball division and in the EuroLeague among other national-level competitions. The injuries were recorded using a validated medical questionnaire that included information according to type, severity, location, and injury mechanism. Training and match times were also recorded for each player in order to calculate injury incidence.

RESULTS

A total of 306 injuries were reported, representing 12.59 injuries per 1000 h of basketball play. Most injuries occurred without direct contact with another player/object (70.9%) and were located in the lower limbs (74.8%), particularly in the knee (22.9%). The incidence of injuries was higher during competition than during training: 77.83 vs. 8.29 injuries per 1000 h of basketball play. However, there were no differences in the mechanism and mode of onset between training and competition injuries while the proportion of time-loss injuries was also similar in training and competition.

CONCLUSIONS

In summary, injury incidence in professional basketball was ~10-times higher during competition than during training. Beyond differences in incidence, injury characteristics were similar for basketball training and competition.

Augmented stress weightbearing CT for evaluation of subtle tibiofibular syndesmotic injuries in the elite athlete

OBJECTIVE

We aim to present a novel imaging technique utilizing weight-bearing CT with syndesmotic stress to identify subtle, unstable syndesmotic injuries. We illustrate this with a case presentation of such an injury in an elite athlete that ultimately required operative fixation.

MATERIALS AND METHODS

In order to perform an augmented stress weightbearing CT, the patient is in the standing position, feet facing forward, and with weight distributed equally. The patient is then coached to internally rotate the shin and knee. This places an external rotational moment on the TFS due to the planted foot and ankle. The augmented stress images undergo 3D reconstruction and post-processing to render coronal and sagittal images. These are subsequently compared to standard, conventional weightbearing CT images performed without the external rotation stress.

RESULTS

We illustrate this technique by presenting a case in which a 21-year-old collegiate athlete sustained a Grade II syndesmotic injury, diagnosed by MRI and clinical exam without evidence of instability by standard weightbearing CT or weightbearing radiographs. After undergoing the augmented stress weightbearing CT, the instability was noted. This prompted subsequent operative fixation and ultimately return to sport.

CONCLUSION

We propose this technique for diagnosing unrecognized, subtle dynamically unstable syndesmosis injuries where clinical suspicion persists despite negative imaging, particularly in the elite athlete.

High return to play rate following treatment of multiple-ligament knee injuries in 136 elite athletes

PURPOSE

The purpose of the study is to assess return to play rate and timing of elite athletes treated for multi-ligament knee injuries with modern surgical techniques.

METHODS

A retrospective review was performed of all professional or national/international level athletes treated for a multi-ligament knee injury by the senior author in the period from February 2001 to October 2019, with a minimum of 2-year follow-up. The study cohort consisted of 136 elite athletes who underwent surgery of two or more knee ligaments. Outcomes measures were return to play (RTP), defined as return to elite level sport, return to play time, and further surgical procedures.

RESULTS

One hundred and twenty (88.2%) athletes returned to elite level sport at an average of 12.8 months from operation. In unicruciate injuries, ACL and PCL-based injuries had similar return to play rates (89.1% vs. 87.5% respectfully, n.s.) although mean RTP time was longer in those with PCL-based injuries (15.2 vs. 11.9 months, p < 0.01). Bicruciate injuries had longer RTP times compared to unicruciate injuries (mean RTP 16.0vs. 12.4 months, p < 0.05) but were able to return at a similar rate (83.3% vs. 88.9%, n.s.). Medial and lateral sided injuries had similar RTP rates (89.3% vs. 87.9%, n.s.) though lateral sided injuries took longer before returning to play (13.4 vs. 11.6 months, p < 0.05). Further surgery was required in 54 (39.9%) patients including 25 (18.4%) manipulations under anaesthesia. Four (2.9%) of the athletes underwent revision ligament surgery.

CONCLUSION

Modern surgical techniques used in the treatment of multi-ligament knee injuries can lead to high return to play rates in elite athletes.

LEVEL OF EVIDENCE

IV.

Triple careers of athletes: exploring the challenges of planning a pregnancy among female elite athletes using semi-structured interviews

Background

The challenging factors that elite athletes perceive for combining their sportive career with planning a pregnancy and motherhood need to be identified in order to develop supportive measures. Therefore, this phenomenological qualitative study aimed to explore challenges associated with planning a pregnancy among female, non-pregnant elite athletes.

Methods

Semi-structured skype-interviews were performed among female elite athletes (athletes competing on national or international level) aged 28 years or older. Using Mayring’s qualitative content analysis approach, anchor examples served to identify potential challenges of planning a pregnancy which were categorized independently by two researchers.

Results

Interviews of 16 elite athletes (mean age 30.7 years) entered analysis. Eleven challenges of planning a pregnancy were identified, categorized into organizational / environmental, financial, personal, and physical factors.

Conclusions

With regard to financial challenges, we propose mandatory maternity leave and continuation of the contracts and salary. Furthermore, mentoring programs may help to provide support and advice to new generations of female elite athletes and help to reduce concerns regarding the wish of becoming pregnant during a sportive career. In order to reduce physical concerns regarding pregnancy and exercise, we see a need for scientific studies investigating the association of sport discipline specific characteristics on sportive performance and the mother´s, fetus’ and child´s health. Finally, the results of the current study may be used in future quantitative studies to test specific hypotheses.

Treatment Considerations for Compulsive Exercise in High-Performance Athletes with an Eating Disorder

Compulsive exercise is linked with poorer treatment outcomes in people with eating disorder (EDs). High-performance athletes represent a growing and complex subcomponent of the broader ED population, and emergent evidence indicates that different conceptualisations of compulsive exercise are needed in this population. Existing randomised controlled trials in ED populations have demonstrated small treatment effects on compulsive exercise compared with control groups; however, athletes were sparsely sampled across these studies. Thus, the extent to which current treatments for compulsive exercise in EDs are also effective in high-performance athletes is unknown. For this opinion paper, we sought representation from high-performance sports leadership, someone with lived experience of both an ED and high-performance athletics, and ED clinical experts. We discuss the utility of recommending exercise abstinence in ED treatment with athletes, as well as a number of other treatment strategies with some evidence in other contexts for further consideration and research in this population. These include using mindfulness-based interventions as an adjunct to cognitive-behavioural therapies, using wearable technologies and self-reported fatigue to inform training decisions, and incorporating greater exercise variation into training programs. We also offer practical considerations for clinicians seeking to apply foundational elements of cognitive-behavioural interventions (e.g., exposure and response prevention, cognitive restructuring, behavioural experiments) into an ED treatment program for a high-performance athlete. Future research is needed to examine characteristics of pathological compulsive exercise in athletes and whether available treatments are both feasible and effective in the treatment of compulsive exercise in athletes with an ED.

Problem Gambling and Problem Gaming in Elite Athletes: a Literature Review

Researchers have raised concerns about mental health in elite athletes, including problem gambling, where research hitherto is scarce. While gambling has been assessed in the younger student-athlete population, neither gambling nor the recently recognized behavioral addiction of gaming disorder has been sufficiently addressed in the elite athlete population. The present systematic literature review aimed to summarize research knowledge on the prevalence and correlates of problem gambling and problem gaming in elite athletes. Research papers were searched systematically using the Scopus, PsycINFO, and PubMed/MEDLINE databases and evaluated following a PRISMA paradigm. For the elite athlete population, eight reports on problem gambling and one report on problem gaming were found. While at least five papers indicated an increased risk of problem gambling in elite athletes compared to the general population, one study from Australia indicated the opposite. Problem gambling was generally more common in male athletes. Knowledge of problem gaming prevalence is thus far limited. It is concluded that increased research in problem gambling and problem gaming in elite athletes is warranted.

Do Rates of Mental Health Symptoms in Currently Competing Elite Athletes in Paralympic Sports Differ from Non-Para-Athletes?

Background

This study addresses the lack of comparative data on the mental health of athletes in Paralympic sports (‘para-athletes’) and non-para athletes by examining the prevalence and correlates of mental health symptoms in a national sample of elite athletes representative of the population from which it was drawn on age and para-status.

Methods

A cross-sectional, anonymous, online-survey was provided to all categorised (e.g. highest level) athletes, aged 17 years and older, registered with the Australian Institute of Sport (n = 1566). Measures included psychological distress, mental health caseness, risky alcohol consumption, body weight and shape dissatisfaction, self-esteem, life satisfaction, and problem gambling. Correlates of outcomes included individual (e.g. demographic and psychosocial) and sport-related variables.

Results

The participation rate was 51.7% (n = 810), with valid data available from 749 athletes. No significant differences were observed between athletes from para- and non-para-sports on most mental health symptoms, with the exception of alcohol consumption (p < .001) and self-esteem (p = .007), both lower in athletes from para-sports. A trend for an interaction was found for anxiety and insomnia (p = .018), whereby the difference between athletes from para- and non-para-sports was qualified by gender.

Conclusions

In a large sample of elite athletes, mental health and wellbeing symptoms are comparable between athletes from para- and non-para-sports, with the exception of para-athletes reporting lower alcohol consumption but also lower self-esteem. While overall mental health and wellbeing symptom profiles are largely similar, attention to areas of differences will help to better address the unmet and distinct mental health needs of athletes from para-sports.

Transient Quadriparesis and Cervical Neuropraxia in Elite Athletes

Elite athletes are often faced with difficult decisions when faced with a cervical spinal disorder. There are many aspects to consider such as the risk of further injury, short- and long-term effects on an athlete's life both during and after his/her career, and the options for treatment. Although there have been some recent contributions to this topic, the evidence-based literature is generally devoid of high-level clinical studies to help guide the decision-making process. This article reviews the pertinent available data/criteria and offer an algorithm for return-to-play considerations.

Effects of acute ingestion of caffeinated chewing gum on performance in elite judo athletes

Purpose

Previous investigations have found positive effects of acute ingestion of capsules containing 4-to-9 mg of caffeine per kg of body mass on several aspects of judo performance. However, no previous investigation has tested the effectiveness of caffeinated chewing gum as the form of caffeine administration for judoists. The main goal of this study was to assess the effect of acute ingestion of a caffeinated chewing gum on the results of the special judo fitness test (SJFT).

Methods

Nine male elite judo athletes of the Polish national team (23.7 ± 4.4 years, body mass: 73.5 ± 7.4 kg) participated in a randomized, crossover, placebo-controlled and double-blind experiment. Participants were moderate caffeine consumers (3.1 mg/kg/day). Each athlete performed three identical experimental sessions after: (a) ingestion of two non-caffeinated chewing gums (P + P); (b) a caffeinated chewing gum and a placebo chewing gum (C + P; ~2.7 mg/kg); (c) two caffeinated chewing gums (C + C; ~5.4 mg/kg). Each gum was ingested 15 min before performing two Special Judo Fitness Test (SJFT) which were separated by 4 min of combat activity.

Results

The total number of throws was not different between P + P, C + P, and C + C (59.66 ± 4.15, 62.22 ± 4.32, 60.22 ± 4.08 throws, respectively; p = 0.41). A two-way repeated measures ANOVA indicated no significant substance × time interaction effect as well as no main effect of caffeine for SJFT performance, SJFT index, blood lactate concentration, heart rate or rating of perceived exertion.

Conclusions

The results of the current study indicate that the use of caffeinated chewing gum in a dose up to 5.4 mg/kg of caffeine did not increase performance during repeated SJFTs.

No relationship between the nordic hamstring and two different isometric strength tests to assess hamstring muscle strength in professional soccer players

OBJECTIVES

To investigate the relationship between one eccentric and two isometric tests commonly used to assess hamstring strength in professional soccer.

SETTINGS

Professional soccer club.

DESIGN

Cross-sectional study.

PARTICIPANTS

Twenty male professional soccer players.

MAIN OUTCOME MEASURES

Hamstring force was quantified during 3 tests (Nordic hamstring eccentric, 90:20 isometric posterior-chain strength and isometric 15° knee flexion) using a load cell, a handheld dynamometer and a force platform, respectively.

RESULTS

Poor relationships and low concordance were observed between isometric and eccentric tests, showing different ability to discriminate hamstring weakness and asymmetries. The Nordic hamstring test identified between-limb asymmetry >15% in 30% of the players, 25% in the 15° knee flexion and 5% in the 90:20 test. All players obtained different results in the three tests with only one showing asymmetry >15% in two tests.

CONCLUSION

Results obtained in each test cannot inform the others. Mechanical outputs of these tests must be used for particular purposes during the prevention, rehabilitation and monitoring process of hamstring injury. Isometric testing might be preferable during the initial phases of the recovery process of a hamstring injury while the Nordic hamstring test might be used in the last stages or detect muscle weakness/asymmetries in non-injured players.

Elite athletes' experiences of musculoskeletal pain management using neuroanatomical dry needling: A qualitative study in Swedish track and field

OBJECTIVES

To investigate how elite track and field athletes with a history of musculoskeletal pain (MSKP) describe their perceptions of clinical treatments based on dry needling guided by a neurological map (neuroanatomical dry needling (naDN)).

DESIGN

Qualitative study.

METHODS

In-depth interviews were conducted with eight elite Swedish track and field athletes (6 males, 2 females, median age 28.5) treated at a clinic specialised in MSKP management. All interviews were audio recorded and transcribed verbatim. The data were structured and analysed using a thematic method.

RESULTS

The athletes approached clinical MSKP treatment from a performance-orientated perspective. They explained that they inevitably suffered MSKP episodes due to the intense physical demands of their sport. The use of naDN was considered an integral part of their sports practice and the study clinic's services were readily utilised when MSKP caused minor reductions in physical capacity. The athletes appreciated an unambiguous anatomical diagnosis, preferably supported by imaging scans, as this increased their confidence in clinical services. They valued the naDN treatment as it was perceived to provide fast-acting analgesia that enabled rapid return-to-play. These factors combined to reduce performance-related stress.

CONCLUSIONS

Elite track and field athletes with a history of MSKP sought and appreciated clinical treatment with naDN largely because it provided fast-acting analgesia that enabled rapid return-to-play at a high-performance level. These athletes' expectations of MSKP diagnosis and management appear incongruent with current research indicating that MSKP sensitivity within the nervous system does not accurately reflect musculoskeletal tissue state or recovery following tissue damage.

Understanding the effects of the menstrual cycle on training and performance in elite athletes: A preliminary study

Success at an Olympic level can come down to the smallest of margins. However little research has been conducted into how the menstrual cycle affects elite athletes' performance and decision making. This study uses a combination of quantitative and qualitative research methods to explore this question. Physiological performance data was collected from eight elite athletes for 7 months and analyzed as a function of menstrual phase. The Cambridge Gambling Task (CGT) was used to test decision making and testing occurred twice in one cycle, during the early follicular phase and during the mid-luteal phase. Menstrual cycle phase was determined using menstrual cycle mapping and urine ovulation tests. In the qualitative part of this project, two elite athletes, two Olympic level athletes, and two coaches participated in semi-structured interviews. The study found that physiological performance was significantly better during the menses phase (MP) compared to the proliferative and secretory phases (PSP). There was variation in how elite athletes were individually affected however. Oral contraceptive users showed a greater performance change from MP to PSP suggesting that oral contraceptives may be detrimental to performance in some athletes. The results of the CGT showed that impulsivity is significantly affected by menstrual cycle phase. Risk taking, error rates and response times were not affected. The qualitative interviews revealed that elite athletes and their coaches understand little of the menstrual cycle. Despite this, there are preconceptions that it negatively effects performance during the menses phase. The findings suggest that the menstrual cycle can have a significant effect on an elite athlete's performance and this paper discusses how individuals can possibly improve aspects of physiological and psychological performance by understanding and monitoring their menstrual patterns.

The Australian Institute of Sport framework for rebooting sport in a COVID-19 environment

Sport makes an important contribution to the physical, psychological and emotional well-being of Australians. The economic contribution of sport is equivalent to 2-3% of Gross Domestic Product (GDP). The COVID-19 pandemic has had devastating effects on communities globally, leading to significant restrictions on all sectors of society, including sport. Resumption of sport can significantly contribute to the re-establishment of normality in Australian society. The Australian Institute of Sport (AIS), in consultation with sport partners (National Institute Network (NIN) Directors, NIN Chief Medical Officers (CMOs), National Sporting Organisation (NSO) Presidents, NSO Performance Directors and NSO CMOs), has developed a framework to inform the resumption of sport. National Principles for Resumption of Sport were used as a guide in the development of 'the AIS Framework for Rebooting Sport in a COVID-19 Environment' (the AIS Framework); and based on current best evidence, and guidelines from the Australian Federal Government, extrapolated into the sporting context by specialists in sport and exercise medicine, infectious diseases and public health. The principles outlined in this document apply to high performance/professional, community and individual passive (non-contact) sport. The AIS Framework is a timely tool of minimum baseline of standards, for 'how' reintroduction of sport activity will occur in a cautious and methodical manner, based on the best available evidence to optimise athlete and community safety. Decisions regarding the timing of resumption (the 'when') of sporting activity must be made in close consultation with Federal, State/Territory and/or Local Public Health Authorities. The priority at all times must be to preserve public health, minimising the risk of community transmission.

The Trials and Tribulations of an Indian Ace Shooter: The Road to Gold

Athletes that excel in their field, and are hence declared "elite", have many challenges and problems in their career. The path to glory is often littered with personal sacrifice, rigorous schedules and many related medical issues from orthopaedic injuries specific to individual sports, to mental health issues that are often not diagnosed. Coupled with that, the lack of support to these sportspersons in underdeveloped countries, makes their road to the top much more challenging. Commitment of time, continuance of effort and perseverance are key components. The current account of a difficult journey and the issues that were overcome serves as a guide to aspiring athletes and to support staff ranging from doctors to physiotherapists and perhaps even the sports administrators.

Analysis of doping control test results in individual and team sports from 2003 to 2015

BACKGROUND

Determining the prevalence of doping in sport might be useful for anti-doping authorities to gauge the effectiveness of anti-doping policies implemented to prevent positive attitudes toward doping. Using questionnaires and personal interviews, previous investigations have found that the prevalence of doping might be different among different sports disciplines; however, there is no sport-specific information about the proportion of adverse and atypical findings (AAF) in samples used for doping control. The aim of the present investigation was to assess the differences in the frequency of adverse analytical and atypical findings among sports using the data made available by the World Anti-Doping Agency.

METHODS

The data included in this investigation were gathered from the Testing Figures Reports made available annually from 2003 to 2015 by the World Anti-Doping Agency. These Testing Figures Reports include information about the number of samples analyzed, the number of AAFs reported, and the most commonly found drugs in the urine and blood samples analyzed. A total of 1,347,213 samples were analyzed from the individual sports selected for this investigation, and 698,371 samples were analyzed for disciplines catalogued as team sports.

RESULTS

In individual sports, the highest proportions of AAF were 3.3% ± 1.0% in cycling, 3.0% ± 0.6% in weightlifting, and 2.9% ± 0.6% in boxing. In team sports, the highest proportions of AAF were 2.2% ± 0.5% in ice hockey, 2.0% ± 0.5% in rugby, and 2.0% ± 0.5% in basketball. Gymnastics and skating had the lowest proportions at (≤1.0%) for individual sports, and field hockey, volleyball and football had the lowest proportions for team sports (≤1.4%).

CONCLUSION

As suggested by the analysis, the incidence of AAF was not uniform across all sports disciplines, with the different proportions pointing to an uneven use of banned substances depending on the sport. This information might be useful for increasing the strength and efficacy of anti-doping policies in those sports with the highest prevalence in the use of banned substances.

Sport-Specific Use of Doping Substances: Analysis of World Anti-Doping Agency Doping Control Tests between 2014 and 2017

Background: In recent years, there has been a solid effort across all sports organizations to reduce the prevalence and incidence of doping in sport. However, the efficacy of current strategies to fight against doping might be improved by using anti-doping polices tailored to the features of doping in each sport. Objectives: The aim of this investigation was to analyze the substances more commonly found in doping control tests in individual and team sports. Material and Methods: The publicly accessible Testing Figures Reports made available by the World Anti-Doping Agency, were analyzed from 2014 to 2017. Results: The most commonly detected groups of banned substances were anabolic agents and stimulants but the distribution of adverse findings per drug class was very different depending on the sports discipline. Weightlifting, athletics, rugby, hockey and volleyball presented abnormally high proportions of anabolic agents (p = 2.8 × 10^-11). Cycling, athletics and rugby presented atypically elevated proportions of peptide hormones and growth factors (p = 1.4 × 10^-1). Diuretics and masking agents were more commonly found in boxing, wrestling, taekwondo, judo, shooting, and gymnastics than in other sports (p = 4.0 × 10^-68). Cycling, rowing, aquatics, tennis, gymnastics and ice hockey presented abnormally high proportions of stimulants (p = 1.8 × 10^-5). Conclusions: These results indicate that the groups of banned substances more commonly detected in anti-doping control tests were different depending on the sports discipline. These data suggest the prohibited substances used as doping agents might be substantially different depending on the type of sport and thus, sports-specific anti-doping policies should be implemented to enhance the efficacy of anti-doping testing.

The effects of mindfulness training on competition-induced anxiety and salivary stress markers in elite Wushu athletes: A pilot study

OBJECTIVE

Due to the impact of stress and related psychophysiological responses on competitive performance, psychological interventions that reduce stress and may thus increase athletic performance need to be evaluated. In this pilot study, the effects of a mindfulness-based intervention (MBI) on competitive anxiety, self-confidence and mindfulness, and autonomic and endocrine stress responses to a competition in elite athletes were explored.

METHODS

Twenty-six male elite Wushu athletes (N = 26) were randomly assigned to either MBI (8 weeks) or a wait-list control group. Both groups participated in three competitions at baseline, immediately post intervention, and at a 2-month follow-up. Athletes completed the Competitive State Anxiety Inventory-2 prior to the competitions. Saliva, from which the stress markers cortisol (sCort) and alpha-amylase (sAA) were determined, was collected prior to and after competitions as well as after awakening and in the evening of competition days.

RESULTS

Repeated measures ANOVAs showed that the MBI group, but not the wait-list control group, demonstrated an increase in self-confidence and mindfulness and a decrease in competitive anxiety from baseline to post intervention (all p < .001, all ɳ_p² > 0.39). The MBI group exhibited lower sCort daily levels (p = .001, ɳ_p² = 0.332) and lower sCort (p = .013, ɳ_p² = 0.121) and sAA responses (p = .022, ɳ_p² = 0.119) to the competition after the intervention. Daily sAA was unaffected by the intervention (p = .742, ɳ_p² = 0.011). These changes remained stable up to the 2-month follow-up.

CONCLUSIONS

The present pilot study suggested that mindfulness-based intervention might be associated with a diminished physiological and psychological stress responses to competition. Whether this in turn translates to change in performance needs to be examined in future studies with larger samples. Moreover, different sport activities need to be considered before findings can be generalized.

Prevalence and patterns of dietary supplement use in elite Spanish athletes

Background

Dietary supplementation is a common strategy to achieve a specific health status or performance benefit. Several investigations have focused on the prevalence of dietary supplement use by athletes. However, information on how athletes manage the use and purchase of dietary supplements is scarce.

Methods

Five hundred and twenty-seven high-performance athletes (346 males and 181 females), participating in individual and team sports, completed a validated questionnaire about use and purchase patterns of dietary supplements. The dietary supplements were categorized according to the International Olympic Committee (IOC) consensus.

Results

Sixty four percent of the athletes (n = 337) used dietary supplements (median = 3; range 1 to 12). Age, sex, type of sport, level of competition, and professionalism influenced the prevalence of dietary supplement use (all p < 0.05). The most prevalent dietary supplement consumed was proteins (41%; n = 137), followed by amino acids/BCAA-based supplements (37%; n = 124). Additionally, as per group of supplements according to IOC consensus, 18% of the supplements were rated as having a low level of scientific evidence (e.g., glutamine, HMB, L-carnitine, etc). Most athletes (45%, n = 152) purchased dietary supplements in a store and 24% (n = 81) obtained them from a sponsor. Most athletes also (42%, n = 141) reported a self-organization of supplementation and did not consult with any professional. Last, 81% (n = 273) of athletes consuming supplements did not know any platform to check supplement safety/quality. For those who do not use dietary supplements (36% of the total sample, n = 190), most reported that they do not consider supplements necessary (72%, n = 137).

Conclusion

Dietary supplementation appears to be widely used in sport with a considerable proportion of athletes consuming supplements with low level of scientific evidence. Additionally, athletes seem to rely on inadequate sources of information and may be largely unaware of sources to detect supplement contamination.

Neurocognitive Performance of 425 Top-Level Football Players: Sport-specific Norm Values and Implications

OBJECTIVE

Concussion diagnosis and management in sports largely relies on neurocognitive testing. In the absence of baseline assessment, only norm values of the general population are available for comparison with scores of concussed athletes. To evaluate whether (elite) sport specific norm values are needed, cognitive performance was compared between top-level football players and the general population.

METHODS

Cognitive performance of 425 top-level football players was evaluated using the computerized test battery CNS Vital Signs. Players were split into two age groups (15-19 and 20-29 years) and test results were compared with a norm sample (n = 268) by means of age-standardized scores using Cohen's d effect size statistics.

RESULTS

The younger age group outperformed the norm sample in all domains, with small to moderate effects on tests of processing speed (d = 0.58, 95% CI = 0.31,0.85), cognitive flexibility (d = 0.27, 95% CI = 0.01,0.53) and psychomotor speed (d = 0.97, 95% CI = 0.69,1.24). In the older age group, no differences were found on four out of six domains; a moderate positive effect was found for psychomotor speed (d = 0.74, 95% CI = 0.54,0.93), a small negative effect for reaction time (d = -0.47, 95% CI = -0.66,-0.28). Relative to the norm, older football players scored lower than younger football players on all test domains.

CONCLUSION

Cognitive performance of elite football players may be different from the general population. It is recommended to use football-specific norm scores for comparison with test results of concussed players, and to choose an adequate control group when investigating effects of contact sport on cognition. Studies with older/retired football players are needed to further analyze potential sport-specific age effects.

Effectiveness of taping on functional performance in elite athletes: A systematic review

Taping has been showing its effect on the rehabilitation aspect with numerous reviews. However, there is lack of evidence on the effect of taping on functional performance, espectially in elite sports settings. This review aimed to evaluate the effectiveness of taping intervention on sports-related functional performance among the elite athlete population. Online databases such as Ovid MEDLINE, ProQuest, PubMed, ScienceDirect, Scopus, SPORTDiscus, and Web of Science were searched. Eligibility criteria were listed as follows: (i) English, (ii) academic journal, (iii) research article, (iv) elite or professional athletes, (v) experimental research design, (vi) sport, (vii) taping, and (viii) functional performance. Specific emphases were targeted on within-subject comparison and healthy subjects. The PEDro scale was utilized for appraising on the statistical information, as well as internal and external validity. The Cohen's d effect size with 95 percent confidence intervals was used to compare taped versus not-taped condition. Nine studies were included in this review and 25 comparisons were extracted. Positive effects were found on balance performance with rigid tape, and horizontal jump performance with elastic tape. Alternatively, negative effects were found on vertical jump performance. An interesting finding was noted on the effect of taping applied after 24 h. Overall, taping could be a beneficial practice for elite sports performance.

A novel role of probiotics in improving host defence of elite rugby union athlete: A double blind randomised controlled trial

OBJECTIVE

To examine the effects of a probiotic protocol on the incidence and severity of respiratory and gastrointestinal infections in elite rugby union athletes across an international competition season. Associations were also investigated between salivary biomarkers of stress (cortisol, alpha-amylase) and mucosal immunity (secretory(s)-IgA).

DESIGN

A double-blind RCT was conducted over 27-weeks, divided into three stages: (1) control period; (2) domestic competition; and (3) international competition.

METHODS

Athletes were assigned a probiotic (n = 9) or placebo (n = 10) supplement. Ultrabiotic 60™ or placebo was taken with food twice daily for 17 weeks and SB Floractiv™ 250 mg added twice daily during stage three.

RESULTS

Five infections were diagnosed by the team sports physician across the 27-weeks, three within the intervention period in athletes randomised to the placebo group. No significant group x time interaction effects for salivary cortisol, alpha-amylase or s-IgA were identified over the 27-week time period, although a significant main effect for group and time was identified for salivary cortisol, alpha-amylase, and s-IgA (p < 0.05 for all). When considering stage, significant differences were identified in stage one with s-IgA lower in the probiotic group (p = 0.015). In stage two and three, salivary cortisol was higher in the probiotic group (p = 0.016 and p = 0.001 respectively), and salivary alpha-amylase was higher in the probiotic group in stage three (p = 0.007).

CONCLUSION

The probiotic protocol used in this study was associated with an increase in salivary alpha-amylase supporting its possible role as a host defence peptide.

Left ventricular hypertrophy in world class elite athletes is associated with signs of improved cardiac autonomic regulation

AIM

In this study we sought to assess whether in elite athletes the physiological increase in cardiac mass attending severe long-term training leading to athlete's heart is accompanied by an improvement of autonomic performance, as assessed by post exercise vagal indices and a novel unitary Autonomic Nervous System Index for sports (ANSIs).

METHODS

The study involved 500 elite athletes (23.9 ± 6.4 years) participating in a screening organised by the National Italian Olympic Committee. All subjects underwent a complete medical examination, rest and stand autonomic assessment (heart rate variability) as well as bicycle exercise. ANSIs was also derived as radar plot from rest, stand and heart rate recovery individual proxies of autonomic nervous system regulation. All subjects were grouped into those with left ventricular hypertrophy present (LVH(+)), or not (LVH(-)), according to recognised thresholds.

RESULTS

We observed that LVH(+) athletes (24.8%) showed a marked increase of post-exercise vagal indices ( p < 0.001) and of ANSIs ( p < 0.001), while no difference was observed for heart-rate variability indices. These changes were contingent upon sport intensity categories.

CONCLUSIONS

Elite athletes with physiological cardiac hypertrophy (LVH(+)) present a selective profile of indices of autonomic nervous system performance, characterised by increases of markers of vagal recovery and of the novel unitary autonomic index for sports while RR variance and spectral indices seem to be unmodified. Athlete's heart may be characterised by a specific combination of anatomical and neurocardiac remodeling. This approach might furnish potential warning signs differentiating normal training induced physiology from pathological adaptation.

Subtotal Occlusion of Left Anterior Coronary Artery in a Professional Athlete

Screening for cardiovascular disease in athletes is crucial to avoid life-threatening complications. Here, we present the case of a fairly asymptomatic young professional soccer player with several cardiovascular risk factors, who proved to have significant coronary artery disease on coronary computed tomography which was ordered based on clinical suspicion and his family history. Informed consent for publication was obtained from the patient.

Management of Rotator Cuff Injuries in the Elite Athlete

PURPOSE OF REVIEW

Rotator cuff injuries are a common cause of pain and dysfunction for the elite athlete and can result in time loss from participation. This review highlights the current management of these injuries.

RECENT FINDINGS

Conservative management of rotator cuff injuries continues to be the "gold standard" in the elite athlete. This includes a comprehensive rehabilitation program, anti-inflammatories, and corticosteroid injections. Newer treatment techniques such as intramuscular dry needling and the use of biologics such as platelet-rich plasma and stem cells demonstrate early promising results; however, these modalities require further investigation to determine their effectiveness. Rotator cuff injuries can range from contusions and tendinopathy to full-thickness tears. A comprehensive evaluation is needed to determine the extent of injury and appropriate plan of care. Management strategies can range from rehabilitation to operative intervention and are guided by the size of the tear, time of season, sport, performance limitations, and presence of concomitant pathology.

Influences of perfectionism and motivational climate on attitudes towards doping among Korean national athletes: a cross sectional study

BACKGROUND

The motives for elite athletes to dope are related primarily to maintaining and improving their physical performance. Especially, elite athletes training to compete in the Olympics may feel unique situational pressure, which may in turn induce powerful motivation for doping and predict doping behavior. This study aimed to investigate possible factors associated with attitudes towards doping in Korean national athletes who competed in the Rio 2016 Olympic Games.

METHODS

A total of 198 athletes (95 female, 103 male) completed the questionnaire, which covered demographic information, doping-related experiences, Performance Enhancement Attitude Scale (PEAS), Perfectionism in Sports Scale (PSS; coach's criticism, concern over mistakes, and personal standards), and Perceived Motivational Climate in Sport Questionnaire-2 (PMCSQ-2; ego-involving and task-involving climates). Pearson's correlation coefficients were used to identify correlations among PEAS, PSS, and PMCSQ-2 scores, and stepwise multiple linear regression was performed to investigate possible factors significantly associated with attitudes towards doping.

RESULTS

The coach's criticism of PSS was slightly or weakly related to the concern over mistakes of PSS and the ego-involving climate of PMCSQ-2, respectively. And the concern over mistakes sub-scale of perfectionism was related to attitudes towards doping, but weakly.

CONCLUSIONS

Effective anti-doping policy should meet athletes' perfectionism, and more studies that identify other factors that influence athletes' doping attitudes are needed.

Asymptomatic elite young tennis players show lateral and ventral growth plate alterations of proximal humerus on MRI

PURPOSE

The specific aim of the study was to investigate and compare epiphyseal length and extension in the proximal humerus, closure in the growth plate and bone marrow signal intensity related to the proximal humeral physis in the dominant arm and the non-dominant arm of the asymptomatic adolescent elite tennis player.

METHODS

The study sample included 35 asymptomatic elite young tennis players (15 males and 20 females, mean age 17.4 years ± 2.7). Each player contributed with two shoulders to the MRI measurement. The non-dominant arm was used as a control.

RESULTS

Relative reliability between the radiologists was excellent (ICC 0.78-0.96). Statistically significant differences between dominant arm and non-dominant arm in epiphyseal length (mm) laterally (DA 27.3 vs NDA 26.7) were shown. Statistically significant differences were also found in epiphyseal extension (mm) laterally (DA 36.1 vs NDA 35.1) and ventrally (DA 36.2 vs NDA 34.8). No statistically significant differences were found between dominant arm and non-dominant arm in epiphyseal extension (mm) medially (DA 31.7 vs NDA 31.7) and dorsally (DA 22.6 vs NDA 22.1).

CONCLUSIONS

Significant findings assessing MRI measurements of the epiphyseal plate in the asymptomatic adolescent elite tennis player might reflect a development of consecutive alterations in the epiphyseal plate in the dominant arm.

LEVEL OF EVIDENCE

Diagnostic study, Level IV.

Comparisons of hip strength and countermovement jump height in elite tennis players with and without acute history of groin injuries

BACKGROUND

Despite the high groin-injury (GI) prevalence in tennis, no studies have assessed the extent to which intrinsic groin injury risk factors, such as hip muscle strength, have recovered in elite tennis players with a history of previous GI.

OBJECTIVE

To investigate whether elite tennis players with a history of GI show differences in hip strength and jump height between injured and uninjured limbs and compared with dominant limb in tennis players without history of acute groin-injuries (NGI).

DESIGN

Cohort study.

PARTICIPANTS

Sixty-one tennis players completed this study: 17 in the GI group and 44 in the NGI. Isometric adductor and abductor hip strength were assessed with a handheld dynamometer, and unilateral counter-movement jump tests were performed on a contact mat connected to an Ergo tester. Paired t-tests were conducted to identify differences between injured and non-injured limbs in the GI group, and independent measures t-tests were conducted to compare between GI and NGI groups.

RESULTS

Isometric adductor strength and adductor/abductor strength ratios were lower in the injured limb (16.4% and 20.1%, respectively) compared with uninjured side within the GI group, and lower than the dominant side in the NGI group. No significant differences were found for unilateral jump heights between sides in the GI, nor isometric abductor strength, when comparing GI to NGI groups.

CONCLUSIONS

Isometric adductor weakness and adductor/abductor strength ratio deficits suggest that adductor muscle strength is not fully recovered in these athletes, potentially increasing their risk of a repeat groin injury.

National Rugby League athletes and tendon tap reflex assessment: a matched cohort clinical study

Background

Limited research suggests elite athletes may differ from non-athletes in clinical tendon tap reflex responses.

Methods

In this matched cohort study, 25 elite rugby league athletes were compared with 29 non-athletes to examine differences in tendon reflex responses. Relationships between reflex responses and lengths of players’ careers were also examined. Biceps, triceps, patellar and Achilles tendon reflexes were clinically assessed.

Results

Right and left reflexes were well correlated for each tendon (r_S = 0.7–0.9). The elite rugby league athletes exhibited significantly weaker reflex responses than non-athletes in all four tendons (p < 0.005). Biceps reflexes demonstrated the largest difference and Achilles reflexes the smallest difference. Moderate negative correlations (r_S = −0.3–0.6) were observed between reflex responses and lengths of players’ careers.

Conclusions

Future research is required to further elucidate mechanisms resulting in the observed differences in tendon reflexes and to ensure clinical tendon tap examinations and findings can be interpreted appropriately in this athletic population.

Feasibility to apply eucapnic voluntary hyperventilation in young elite athletes

INTRODUCTION

Exercise-induced bronchoconstriction (EIB) is more common in athletes compared to the general population. The eucapnic voluntary hyperventilation test is used to detect EIB in adult athletes. It is however unclear whether this technique is also applicable to young athletes.

METHODS

Young athletes (basketball (n = 13), football (n = 19), swimming (n = 12)) were recruited at the start of their elite sports career (12-14 years). Eight age-matched controls were also recruited. Eucapnic voluntary hyperventilation test was performed according to ATS guidelines in all subjects. A second (after 1 year, n = 32) and third (after 2 years, n = 39) measurement was performed in a subgroup of athletes and controls.

RESULTS

At time of first evaluation, 3/13 basketball players, 4/19 football players, 5/11 swimmers and 1/8 controls met criteria for EIB (fall in FEV1≥10% after EVH). A ventilation rate of >85% of the maximal voluntary ventilation (MVV) is recommended by current guidelines (for adults) but was only achieved by a low number of individuals (first occasion: 27%, third occasion: 45%) However, MVV in young athletes corresponds to 30 times FEV1, which is equivalent to 85% of MVV in adults. A threshold of 70% of MVV (21 times FEV1) is feasible in the majority of young athletes.

CONCLUSION

EIB is present in a substantial number of individuals at the age of 12-14 years, especially in swimmers. This underscores the importance of screening for EIB at this age. EVH is feasible in young elite athletes, however target ventilation needs to be adjusted accordingly.