Anabolic/Catabolic Hormone Imbalance but Still Jumping Further? Negative Association of Free Testosterone With Jumping Performance in Elite Handball Players Following a Preparatory Period.

Purpose: The present study investigated the effects of a 10-week preparatory training period on biomarkers and jumping performance and associations of changes in biomarkers, load, and jumping performance from the beginning (PRE) to the end of the preparatory period (POST) in elite handball players. Methods: Seventeen elite handball players competing in the first Slovenian men's League were recruited. Training, competition and academic loads were reported weekly, while biomarkers and jumping performance were assessed at PRE and POST. Results: At POST, decreased levels of free testosterone (large effect size [ES] = -1.69, p < .001) and free testosterone to cortisol ratio [FTCR] (large ES = -.95, p = .004) were observed; whereas, better performance on the single leg lateral hop test [SLLH] (large ES = .85, p = .007) and single leg triple hop test [SLTH] (large ES = 1.05, p = .002) were observed compared to PRE. Furthermore, changes in FTCR correlated with changes in cortisol (high r = -.751, p = .001), SLLH (moderate r = -.603, p = .022), and SLTH (moderate r = -.643, p = .013), while changes in free testosterone correlated with SLTH (moderate r = -.645, p = .013). Conclusions: High intensity trainings with a saturated competition schedule can result in disturbed anabolic/catabolic hormone ratio observed through FTCR decrease, which could indicate either an optimal state or early exhaustiveness. It seems that SLLH and SLTH are more sensitive to changes in biomarkers than a single leg hop test. Sport professionals may use the results for individualized monitoring of an athlete's health and performance, specifically, as an aid for adjusting training loads accordingly to prevent performance declines and potential injury/illness events.

Effects of Oral Iron Supplementation on Blood Iron Status in Athletes: A Systematic Review, Meta-Analysis and Meta-Regression of Randomized Controlled Trials.

BACKGROUND: Iron deficiency in athletes is initially treated with a nutritional intervention. If negative iron balance persists, oral iron supplementation (OIS) can be used. Despite the recent proposal for a refinement of treatment strategies for iron-deficient athletes, there is no general consensus regarding the actual efficiency, dosage, or optimal regimen of OIS. OBJECTIVE: The aim of this meta-analysis was to evaluate to what extent OIS affects blood iron parameters and physical performance in healthy adult athletes. METHODS: PubMed, Web of Science, PEDro, CINAHL, SPORTDiscus, and Cochrane were searched from inception to 2 November 2022. Articles were eligible if they satisfied the following criteria: recruited subjects were healthy, adult and physically active individuals, who used exclusively OIS, irrespective of sex and sports discipline. EXCLUSION CRITERIA: simultaneous supplementation with iron and any other micronutrient(s), intravenous iron supplementation or recent exposure to altitude acclimatisation. The methodological quality of included studies was assessed with the PEDro scale, the completeness of intervention reporting with the TIDieR scale, while the GRADE scale was used for quality of evidence synthesis. The present study was prospectively registered in PROSPERO online registry (ID: CRD42022330230). RESULTS: From 638 articles identified through the search, 13 studies (n = 449) were included in the quantitative synthesis. When compared to the control group, the results demonstrated that OIS increases serum ferritin (standardized mean difference (SMD) = 1.27, 95% CI 0.44-2.10, p = 0.006), whereas blood haemoglobin (SMD = 1.31, 95% CI - 0.29 to 2.93, p = 0.099), serum transferrin receptor concentration (SMD = - 0.74, 95% CI - 1.89 to 0.41, p = 0.133), and transferrin saturation (SMD = 0.69, 95% CI - 0.84 to 2.22, p = 0.330) remained unaltered. Following OIS, a trend of small positive effect on VO2max (SMD = 0.49, 95% CI - 0.09 to 1.07, p = 0.086) was observed in young healthy athletes. The quality of evidence for all outcomes ranged from moderate to low. CONCLUSIONS: Increase in serum ferritin concentration after OIS was evident in subjects with initial pre-supplementation serum ferritin concentration ≤ 12 µg/l, while only minimal, if any effect, was observed in subjects with higher pre-supplementation serum ferritin concentration. The doses of OIS, that induced a beneficial effect on hematological parameters differed from 16 to 100 mg of elementary iron daily, over the period between 6 and 8 weeks. Shorter supplementation protocols have been shown to be ineffective.

Sport and academic engagement of 1,387 Slovenian dual-career athletes before and during COVID-19 lockdown-what did we learn?

Introduction: Since the coronavirus disease outbreak in 2019, there have been several preventive measures and restrictions applied to minimize the transmission of the virus. While lockdown has affected our everyday lives, it has negatively impacted sport and athletes as well. Methods: 1,387 Slovenian dual-career (DC) athletes (47.4% females, 52.6% males) participated in the 22-item questionnaire to gather information on their sports and academic engagement before and during COVID-19 lockdown period. Half of the athletes were enrolled in education at the secondary level (n = 819, aged 15-18 years), while the others were enrolled in primary (n = 301, 8-14 years) and tertiary (n = 267, 19-36 years) education. All participants in the current study have a valid athlete categorization by the Slovenian Olympic Committee and are competing at either junior (31.7%), national (26.9%), prospective (29.5%), international (8.5%), world (2.3%) or Olympic (1.2%) level. Results: DC athletes spent less time on training (-4.7 h; p < 0.001), learning (-1.0 h; p < 0.001), exams (-0.9 h; p < 0.001), laboratory work (-0.6 h; p < 0.001), and other educational activities (-0.3 h; p < 0.001) during COVID-19 lockdown compared to period before the lockdown. Their training environment was changed so they trained either at home or outdoors. Results showed that indoor (-3.7 h; p < 0.001) and team sport athletes (-1.3 h; p < 0.001) trained less than outdoor and individual sports. Male athletes spent more time on training both before (1.3 h; p < 0.001) and during lockdown (1.3 h; p < 0.001) and other sport-related activities (1.3 h; p < 0.001). On the other hand, female athletes spent more time on studying both before (1.5 h; p < 0.001) and during lockdown (2.6 h; p < 0.001). Both sport and educational activities were influenced by athletes' age (p ≤ 0.017). Conclusion: Indoor and team sport athletes were more affected by the governmental measures than outdoor and individual sport athletes. Male athletes experienced a greater decline in learning time compared to female athletes. DC is shown to be beneficial for athletes even in times of COVID-19 lockdown, as DC athletes report smaller decline in motivation, shifting attention from sport to study and having fewer mental problems due to uncertain sports future. The feedback of the preventive measures could serve to assist policy makers and athlete's support staff to form and apply preventive measures that are more effective for DC athletes' training and education.

Effects of physical, psychosocial and dual-career loads on injuries and illnesses among elite handball players: protocol of prospective cohort study.

INTRODUCTION: Health problems in sport cause a major burden on several pillars: sport clubs, health and insurance system and mostly the individual athlete. There is limited knowledge in supporting dual-career athletes firmed on evidence-based research in injury/illness prevention, load and stress management. The main goal of this research approach is to determine how specific physical, psychosocial and dual-career loads affect the occurrence of injuries and illnesses in elite handball players and how much of a variation in the athlete's load leads to an occurrence of an injury/illness. A secondary aim is to determine the association between objective and subjective measures of stress as well as examine the benefits of certain biomarkers to monitor stress, load and injury/illness occurrence in athletes. METHODS AND ANALYSIS: This prospective cohort study, as part of a PhD project, will be carried out on 200 elite handball players of first men's handball league in Slovenia during an entire handball season, lasting from July 2022 to June 2023. Primary outcomes, including health problems, loads and stress, will be assessed weekly on a player level. Other player-related outcomes will include anthropometry, life event survey and blood biomarkers (cortisol, free testosterone and Ig-A), which will be taken three to five times across the observation period according to the players' training cycle. ETHICS AND DISSEMINATION: The project was approved by the National Medical Ethics Committee of Slovenia (number: 0120-109/2022/3) and will be conducted in compliance with the most recent version of Helsinki Declaration. The study results will be published as peer-reviewed articles, congress presentations and as a Doctoral thesis. The results will not only be of importance for the medical and sports community for development of new injury prevention and rehabilitation strategies but also for structuring the correct policy recommendations for athletes' general health. TRIAL REGISTRATION NUMBER: NCT0547129.

Interventions for increasing return to sport rates after an anterior cruciate ligament reconstruction surgery: A systematic review.

Background: An injury followed by surgery poses many challenges to an athlete, one of which is rehabilitation, with the goal of returning to sport. While total restoration of physical abilities is a primary goal for most athletes, psychosocial factors also play an important role in the success of an athlete's return to sport (RTS). The purpose of this review was to examine the effectiveness of exercise and psychosocial interventions on RTS rates, which might be one of the most important outcomes for elite athletes. Methods: To carry out this review, PubMed, SAGE Journals, Web of Science, SPORTDiscus, ScienceDirect, and Google Scholar databases were searched from inception to July 2022. The inclusion criteria consisted exercise or psychosocial intervention for athletes after anterior cruciate ligament reconstruction (ACLR), with reporting RTS rates as an outcome. Results: From 1032 identified articles, four reports (N = 130) met inclusion criteria, all of which examined the recovery after ACLR. The mean MINORS score for the included studies was 16.3 ± 6.1, of which non-comparative studies scored 11.0 ± 1.4, while comparative studies scored 21.5 ± 0.7. There were consistent findings for benefits of exercise and psychosocial interventions on RTS rates. Return to preinjury rates in the reviewed studies vary between 63 and 95% with lower % observed in female athletes and with shorter follow-up. Interventional studies reporting RTS rates with a larger sample size and longer follow-up are needed. Conclusion: Physical and psychological function, as well as social support can be influenced by appropriate interventions, indicating future work on rehabilitation programs for return to preinjury might consider taking the holistic approach addressing those.

The Time Course of Quadriceps Strength Recovery After Total Knee Arthroplasty Is Influenced by Body Mass Index, Sex, and Age of Patients: Systematic Review and Meta-Analysis.

Introduction: For patients with osteoarthritis who have undergone total knee arthroplasty (TKA), quadriceps strength is a major determinant of general physical function regardless of the parameters adopted for functional assessment. Understanding the time course of quadriceps strength recovery and effectiveness of different rehabilitation protocols is a must. Therefore, the aim of this study was to: (i) determine the magnitude of maximal voluntary strength (MVS) loss and the time course of recovery of the quadriceps muscle following TKA, (ii) identify potential moderators of strength outcomes, and (iii) investigate whether different rehabilitation practices can moderate the strength outcomes following TKA, respectively. Design: General scientific databases and relevant journals in the field of orthopedics were searched, identifying prospective studies that investigated quadriceps' MVS pre-to post-surgery. Results: Seventeen studies with a total of 832 patients (39% males) were included. Results showed that in the early post-operative days, the involved quadriceps' MVS markedly declined, after which it slowly recovered over time in a linear fashion. Thus, the greatest decline of the MVS was observed 3 days after TKA. When compared to pre-operative values, the MVS was still significantly lower 3 months after TKA and did not fully recover up to 6 months following TKA. Furthermore, a meta-regression analysis identified that the variables, time point of evaluation, patient age, sex, and BMI, significantly moderate the MVS of the quadriceps muscle. Conclusion: The analyzed literature data showed that the decrease in strength of the involved quadriceps muscles following TKA is considerable and lasts for several months post-surgery. Therefore, we recommend to specifically target the strengthening of knee extensor muscles, preserve motor control, and apply appropriate nutrition to ensure a holistic quadriceps muscle recovery. Since age, sex, and BMI were found to be moderating factors in patients' recovery, further research should include specific analyses considering these moderators.

Tissue Flossing Around the Thigh Does Not Provide Acute Enhancement of Neuromuscular Function.

Nowadays, various methods are used for acute performance enhancement. The most recent of these is tissue flossing, which is becoming increasingly popular for both performance enhancement and rehabilitation. However, the effects of flossing on athletic performance have not been clearly demonstrated, which could be due to differences in the methodology used. In particular, the rest periods between the end of the preconditioning activity and the performance of the criterion task or assessment tools varied considerably in the published literature. Therefore, the present study aimed to investigate the effects of applying tissue flossing to the thigh on bilateral countermovement jump performance and contractile properties of vastus lateralis (VL) muscle. Nineteen recreational athletes (11 males; aged 23.1 ± 2.7 years) were randomly assigned to days of flossing application (3 sets for 2 min of flossing with 2 min rest between sets) with preset experimental pressure (EXP = 95 ± 17.4 mmHg) or control condition (CON = 18.9 ± 3.5 mmHg). The first part of the measurements was performed before and after warm-up consisting of 5 min of cycling followed by dynamic stretching and specific jumping exercises, while the second part consisted of six measurement points after flossing application (0.5, 3, 6, 9, 12, 15 min). The warm-up improved muscle response time (VL = -5%), contraction time (VL = -3.6%) muscle stiffness (VL = 17.5%), contraction velocity (VL = 23.5%), jump height (13.9%) and average power (10.5%). On the contrary, sustain time, half-relaxation time and take-off velocity stayed unaltered. Flossing, however, showed negative effects for muscle response time (F = 18.547, p < 0.001), contraction time (F = 14.899, p < 0.001), muscle stiffness (F = 8.365, p < 0.001), contraction velocity (F = 11.180, p < 0.001), jump height (F = 14.888, p < 0.001) and average power (F = 13.488, p < 0.001), whereas sustain time, half-relaxation time and take-off velocity were unaffected until the end of the study protocol regardless of condition assigned and/or time points of the assessment. It was found that the warm-up routine potentiated neuromuscular function, whereas the flossing protocol used in the current study resulted in fatigue rather than potentiation. Therefore, future studies aimed to investigate the dose-response relationship of different configurations of preconditioning activities on neuromuscular function are warranted.