Acute Calcific Tendinitis of the Flexor Hallucis Brevis Associated With Muay Thai.

Calcific tendinitis manifesting in the foot and toes is a rare condition that often goes unnoticed, even by podiatric specialists and healthcare practitioners. Characterized by an acute onset, this condition presents with pronounced local inflammatory indicators accompanied by pain, often complicating its differentiation from other conditions. We document our experience with a 27-year-old female patient presenting with calcific tendinitis in the flexor hallucis brevis (FHB), along with a review of the relevant literature.

Os Vesalianum Pedis in a Professional Badminton Player: A Case Report.

Os vesalianum pedis (OVP) is one of the exquisite accessory ossicles adjacent to the foot's fifth metatarsal base. Though most of the OVP cases are asymptomatic, only a handful of patients who presented with lateral foot pain have been reported. A 36-year-old professional badminton player presented with swelling and tenderness in the right foot at the metatarsal base. An initial radiographic examination revealed a pseudo-Jones fracture. As a result of persistent pain and concerns regarding OVP, a reassessment of the X-ray was conducted. The examination revealed a radiolucent line with well-defined and well-corticated edges, uniformly separating the ossicle from the metatarsal in the right foot, consequently leading to the diagnosis of OVP. Following diagnosis, the patient was managed conservatively. Os vesalianum is not a common source of pain on the midfoot's lateral side. An oblique radiograph is an appreciable strategy to demonstrate the accessory ossicle. Thus, a careful clinical examination, coupled with the correlation of radiological findings, is a prerequisite to prevent misdiagnosis and overtreatment thereafter.

Comparison between standard hematological parameters and blood doping biomarkers in dried blood spots within the athlete population of Swiss Sport Integrity.

Introduction: The study demonstrated the feasibility of incorporating RNA biomarkers, specifically 5-aminolevulinic acid synthase (ALAS2) and carbonic anhydrase 1 (CA1), to improve the hematological module of the Athlete Biological Passport (ABP) in routine antidoping context. Objective: The aim was to investigate the implementation of reticulocyte (RET) related biomarkers, specifically ALAS2 and CA1, using quantitative reverse transcription polymerase chain reaction (RT-qPCR) on dried blood spots (DBS) from elite athletes. Hemoglobin changes over time in DBS samples was measured as well. Combining hemoglobin and messenger RNA (mRNA) analyses allowed to monitor alterations of the established marker, "DBS OFF-score". Methodology: Ten athletes were selected for sampling by the Swiss national antidoping organization, Swiss Sports Integrity (SSI). Samples were collected, transported and analyzed for ABP following the World Anti-Doping Agency (WADA) procedures and spotted onto Protein Saver DBS cards. Results: Most athletes exhibited stable biomarker levels, except for one individual involved in ski mountaineering, who demonstrated a sustained increase in ALAS2 compared to the individual baseline. This elevation could be due to blood withdrawal or other factors, such as doping with substances outside the targeted test menu. Conclusion: In this study, RNA-biomarkers were successfully analyzed in routine blood samples, and the project demonstrated promising results for the implementation of ALAS2 and CA1 in routine analysis to complement the ABP.

Prospective cohort study identifying risk factors for sports injuries in adolescent athletes: the Healthy Injury-Free Adolescent Athletes (HIFAA) study.

A high incidence of injuries has been reported in young athletes. Several factors have been associated with athletes' sports injuries. However, scientific evidence is lacking, particularly for adolescent athletes. Hence, the Healthy Injury-Free Adolescent Athletes (HIFAA) was designed to evaluate sports injuries and examine associations with risk factors related to physical load and mental health. Secondary aims are to evaluate differences between sex, age, high school year and sports and examine injuries and the athletic situation 5 to 10 years after graduation. Adolescent athletes aged 15-19 years enrolled in high school and competing in sports to reach a national or international level of sports will be included. At inclusion, athletes will sign an informed consent form and fill out a baseline questionnaire addressing potential risk factors (eg, sports, training and competing health and injuries, and psychosocial status). Athletes will then prospectively be monitored weekly regarding injuries, physical (training/match/competing, perceived exertion) and psychological (fatigue, sleep, mental stress, recovery) load until graduation. A shortened version of the baseline questionnaire will be filled out every year, and a follow-up questionnaire regarding injuries, sporting situations and mental health will be filled out 5-10 years after graduation. Injuries are frequent among adolescent athletes, with consequences ranging from shorter interruptions in sports performance to mental health problems and early termination of sports. A reduction of these injuries is warranted. This study will provide a detailed understanding of risk factors, a prerequisite to introducing appropriate preventive measures.

Validation of a sports nutrition knowledge questionnaire for Sri Lankan track and field athletes.

BACKGROUND: While several validated sports nutrition knowledge questionnaires exist, none are specifically designed to assess the sports nutrition knowledge (SNK) of Sri Lankan track and field athletes. This study aims to validate the Sri Lankan Sports Nutrition Knowledge Questionnaire (SLn-SNKQ), tailored for this athlete group, to provide more accurate and meaningful insights for research and practice. This will enable health professionals and coaches to confidently assess athletes' nutrition knowledge, which directly influences their food choices. METHODS: The validity of the questionnaire was established through a multi-step approach. Content validity was achieved via ratings from nutrition experts, all of whom had specialized training in human nutrition and experience of working with athletes. Face validity was evaluated through in-depth telephone interviews with elite or highly trained athletes, using a retrospective think-out-loud protocol to gather feedback on the clarity and relevance of the questions. Construct validity involved nutrition-trained doctors (NTG), non-nutrition-trained professionals (NNTG), and elite-level athletes' groups (AG). Internal consistency was assessed using Cronbach's alpha, and test-retest reliability was evaluated. RESULTS: The final tool comprised 123 individual statements or prompts (items) that were organized into 32 broader questions, spanning 12 sub-sections. Content validity was confirmed by fully integrating 49 out of 70 comments and partially integrating four comments received from nutrition experts for each sub-section. Face validity was established by fully integrating 33 out of 40 comments received from 16 elite and highly trained athletes. Construct validity was confirmed, indicating significant differences in the total scores achieved as a percentage of the SLn-SNKQ among the NTG (462.5, 92.5%), NNTG (223.5, 44.7%), and AG (235, 47.0%; p < 0.001). Reproducibility was established by strong test-retest reliability between individuals' scores on two test attempts, three weeks apart (spearman's correlation; ρ = 0.99, p < 0.05). Internal reliability for each sub-section met psychometric reliability requirements (Cronbach's α > 0.7). CONCLUSIONS: The SLn-SNKQ has been validated and demonstrates robust psychometric properties, offering a reliable tool for assessing SNK among Sri Lankan track and field athletes.

Discrepancies in internal and external training load measurements during low-intensity biathlon training.

Purpose: This study aimed to differentiate external and internal training loads during on-snow biathlon training by adding an accelerometer-derived metric. Methods: Eleven adolescent athletes were fitted with a combined heart rate (HR) and accelerometer to be worn during all training sessions. Duration, HR, training impulse (TRIMP), and average net force ( A v F N e t ) were used as training variables. All training was divided into either low-intensity training (LIT), or high-intensity training (HIT) based on reported intensity. The training was further categorized as training without any shooting practice (NS) or as a combination of skiing and shooting (COMB). Duration, HR, TRIMP, and A v F N e t were analyzed in a linear mixed model for the different training modalities. Results: All training was similar in duration for LIT and HIT sessions (p = .0521) and NS and COMB sessions (p = .988). TRIMP did not differentiate between LIT or HIT training (p = .350) or for NS compared to COMB (p = .298). While A v F N e t decreased during COMB compared to NS during LIT sessions (p < .001) it remained similar during HIT training (p = 1.00). Conclusion: The study's findings indicated that there were no notable differences in internal training load (TRIMP) when comparing various training intensities and modes. However, the type of training had a significant impact on A v F N e t , especially leading to a decrease during COMB sessions under LIT conditions. Incorporating an external load metric could offer a fresh approach when prescribing and evaluating training, providing deeper insights into the training load.

Para-athletes are exposed to bullying as much as non-disabled athletes.

OBJECTIVES: Exposure to bullying and high levels of anxiety are important determinants of the quality and duration of athletes' experiences of success. The aim of this study was to determine which behaviors are most commonly perceived as bullying by para athletes and whether the exposure to bullying or levels of trait anxiety differ between para athletes and non-disabled athletes. METHODS: It is a cross-sectional study. Two groups consisting of professional para athletes (n = 104) and non-disabled athletes (n = 129) between the ages of 18-45 affiliated to the national athletics federation were included in the study. The questionnaire included information about demographics and the two scales, the Negative Acts Questionnaire-Revised (NAQ-R) and the Sport Anxiety Scale-2 (SAS-2). RESULTS: Withholding information that could affect performance and spreading rumors (item 1,5) were the most frequently reported bullying behaviors. No statistically significant difference was found between para athletes and non-disabled athletes or between male and female genders in terms of total or any subdimension NAQ-R scores (p > 0.05). SAS-2 total and SAS-2-worry subdimension scores were significantly lower in the para athletes (p = 0.018 and p = 0.020). Total and all SAS-2 subdimension scores were significantly higher in female athletes (p < 0.05). CONCLUSION: The knowledge about bullying exposure in para-athletes is quite limited. The para-athlete group has fewer opportunities than the non-disabled group in terms of financial opportunities, physical conditions, media coverage and many other aspects. However, in our study, they reported bullying exposure at a similar rate with the non-disabled group. Although there is a similar level of exposure, it is clear that the results will not be similar in the two groups due to the different psychological bases. According to the results of this study, it is thought that stakeholders who have responsibility for the para-athlete group should be further educated.

6-Year Follow-Up of a World Record Breaking Master Marathon Runner.

Endurance performance declines with advancing age. Of the three main physiological factors that determine endurance running performance (maximal oxygen consumption [V̇O2max], lactate threshold, and running economy [RE]), V̇O2max appears to be most affected by age. While endurance performance declines with age, recently, endurance performance has rapidly improved in master athletes as the number of master athletes competing in endurance events has increased. Master athletes represent an intriguing model to study healthy aging. In this case study, we reassessed the physiological profile of a 76-year-old distance runner who broke the marathon world record for men over 70 years of age in 2018. This runner was tested a few months before breaking the world record and retested in 2024. Between 2018 and 2024, his marathon running velocity decreased significantly. Therefore, the purpose of this case study was to determine the physiological changes that explain his performance decline. RE remained similar to 2018, and while there was not a clear breakpoint in blood lactate, he still likely runs marathons at a high percentage (~90%) of his V̇O2max. However, V̇O2max declined by 15.1%. HRmax declined by 3.2% and maximal O2 pulse declined by 12.4%, suggesting that maximal stroke volume and/or arteriovenous O2 difference decreased. Altogether, although this marathoner continues to compete at an elite level, his performance has declined since his record-breaking marathon due to a reduction in V̇O2max. This is likely caused by reductions in maximal stroke volume and/or arteriovenous O2 difference. We speculate that these changes reflect primarily age-related processes.

Medial sleeve fractures in elite-athletes: A heterogeneous group, anatomical and case-based considerations.

PURPOSE: The purpose of this study is to provide a detailed description of the anatomy and radiology of the medial sleeve and present an approach in its management among elite athletes. METHODS: Five cases of elite athletes who underwent treatment for a medial sleeve injury of which the diagnosis was confirmed through physical examination and additional magnetic resonance imaging scan are described in this study. RESULTS: Two patients presented with isolated medial sleeve injuries, while the other three patients suffered from concomitant ankle injuries. Non-operative treatment consisted of relative rest, soft cast immobilization and mobilization in a walking boot or kinesiotape which was successful in four of the cases with regard to the medial sleeve. One patient underwent surgery due to syndesmotic instability. Another patient presented with combined medial and lateral ankle instability which was treated surgically with an open medial and lateral ligament repair. All patients were able to return to their pre-injury sports and at the time of the last follow-up were still playing in their pre-injury level of competition. CONCLUSION: Medial sleeve injuries of the ankle in elite athletes should be considered in the differential diagnosis for athletes presenting with medial ankle pain. Inherent knowledge regarding anatomy is essential when guiding the management of these injuries which can be treated successfully with a non-operative approach consisting of relative rest, immobilization, kinesiotape and physical therapy. In case of persistent medial instability or rotational instability, surgical repair is a viable treatment option. Both modalities allow athletes to return to the pre-injury level of competition. However, early diagnosis is crucial to minimize the delay of appropriate treatment and avoid potential residual symptoms. LEVEL OF EVIDENCE: Level IV.

Left ventricular systolic function after inhalation of beta-2 agonists in healthy athletes.

Inhaled beta-2 adrenoceptor agonists (iß2A) are routinely used as bronchodilators in the treatment of asthma. However, their cardiac effects in athletes are scarcely examined. Thus, the aim of this study was to evaluate the effects of iß2A on left ventricular (LV) systolic function (SF) by echocardiography in healthy, non-asthmatic female and male endurance athletes. A randomized, double-blinded, placebo-controlled, balanced, 4-way complete block cross-over study was conducted. Twenty-four healthy athletes (12f/12m: 22.9 ± 2.7/24.4 ± 4.6 years) randomly completed 4 study arms (placebo; salbutamol; formoterol; formoterol + salbutamol). After inhalation of the study medication, the participants performed a 10-min time trial (TT) on a bicycle ergometer. After each TT an echocardiography was performed to determine LVSF. Blood samples were collected pre, post, 3 h and 24 h post TT. In females, total serum concentrations for salbutamol and formoterol were higher. LV ejection fraction (LVEF) and LV global longitudinal strain (LVendoGLS) showed a treatment effect for the whole study group (p < 0.0001) and a sex effect on LVEF (p = 0.0085). In women, there was a significant treatment effect for all medication arms (at least p ≤ 0.01) both on LVEF and LVendoGLS. In men only formoterol and formoterol + salbutamol displayed a treatment effect on LVEF (p = 0.0427, p = 0.0330; respectively), whereas on LVendoGLS only formoterol + salbutamol was significant (p = 0.0473). The iß2A significantly influenced LVSF after an acute bout of exercise in healthy endurance athletes. These effects were even more pronounced when combining both iß2A that supports a dose-dependent effect on cardiac function. Moreover, female athletes had higher serum concentrations of ß2 agonists and stronger effects on LVSF compared to male athletes. This is mainly explained by differences in body weight and related plasma volume and may indicate a potential risk when increasing dose above the tested concentrations. Trial registration: At the European Union Drug Regulating Authorities Clinical Trials (Eudra CT) with the number 201,500,559,819 (registered prospectively on 09/12/2015) and at the German register for clinical studies (DRKS number 00010574 registered retrospectively on 16/11/2021).

Energy availability and its association with health-related outcomes among national athletes at risk of relative energy deficiency in sports (REDs).

Background: Low energy availability (LEA) occurs when athletes' energy intake fails to match the energy expended during exercise, resulting in insufficient energy to support essential functions for optimal health, a condition known as relative energy deficiency in sports (REDs). Objective: This study aims to explore the prevalence of LEA among Malaysian national athletes and its associations with health-related outcomes. Methods: A total of 43 athletes (51.2% males, aged 18-40) identified previously as having moderate or high risk of REDs through a questionnaire underwent comprehensive clinical assessments. Resting metabolic rate (RMR) was measured using indirect calorimetry, with an RMR ratio of <0.90 indicating LEA. Weight and height were measured, and fasting blood samples were analysed for ferritin, free triiodothyronine (fT3), follicle-stimulating hormone (FSH), luteinising hormone (LH), estradiol (female athletes) and testosterone (male athletes). Bone mineral density (BMD) of the lumbar spine and total left hip, as well as body composition, were measured using dual-energy X-ray absorptiometry (DXA). Results: Out of the 43 athletes, 12 showed evidence of LEA, exhibiting at least one of the following characteristics: low estradiol levels (87.5%), low testosterone (75.0%), low fT3 (66.7%), low LH (58.3%), low FSH (58.3%), low ferritin (25.0%) and low BMD (8.3%). Notably, fT3, estradiol and testosterone were significant predictors for LEA. Conclusions: A low but noteworthy incidence of LEA among Malaysian national athletes was associated with hormone imbalances. Awareness about LEA among athletes and sports personnel is essential for early detection and appropriate intervention.

Corrigendum: Cardiac function and autonomic cardiac function during a multi-stage cycling event: a brief report.

[This corrects the article DOI: 10.3389/fspor.2024.1356577.].

Comparison of Subsequent Surgery After Repair in Bucket-Handle Meniscal Tears and Meniscectomy Analysis of a Large, Contained Cohort Study.

Background: Bucket-handle meniscal tears are large longitudinal vertical meniscal tears that have an attached fragment flipped into the intercondylar notch. Meniscal repair attempts to restore the function of the meniscus and aims to preserve joint mechanics. Alternatively, meniscectomy results in quicker recovery but may lead to future degeneration. Purposes: To evaluate the long-term risk of subsequent ipsilateral knee surgery in patients who underwent a bucket-handle meniscal repair (BHMR) versus meniscectomy/bucket-handle meniscal debridement (BHMD) and assess risk factors associated with subsequent knee surgical intervention. Study Design: Cohort study; Level of evidence, 3. Methods: An electronic health records search for all patients who underwent arthroscopic knee meniscal surgery (repair and meniscectomy) between 2011 and 2018 was performed. Natural language processing was used to search for terms of interest in the long operative notes to determine whether these surgeries were performed for bucket-handle meniscal tears. These patients comprised our initial cohort. Study patients were followed for at least 1 year and for up to 5 years (until December 31, 2019), with censoring at death or membership disenrollment. Baseline patient characteristics and outcomes were evaluated via a database review. The primary outcome was subsequent ipsilateral knee surgeries and secondary outcomes included contralateral knee surgeries, deep surgical site infections, and venous thrombotic events. Multivariable logistic regression analyses were used to model for subsequent surgical treatment of the ipsilateral knee. A subset analysis for patients aged 30 to 50 years was then performed. Results: The median follow-up time was 52.4 months (interquartile range [IQR], 33.5-60 months). A total of 1359 patients underwent BHMR and 1537 patients underwent BHMD. The median age was 24 years (IQR, 17-34 years) for the BHMR versus 38 years (IQR, 27-47 years) for the BHMD group (P < .001). Body mass index (BMI) was significantly lower in the BHMR group compared with the BHMD group (P < .001). BHMR was significantly more likely to be performed during a concomitant ipsilateral anterior cruciate ligament reconstruction (ACLR) than a BHMD (44.2% vs 30.1%, P < .001). During the follow-up period, a total of 656 subsequent ipsilateral procedures were performed in 393 (13.6%) patients. Patients who underwent initial BHMR were at a significantly higher risk of undergoing subsequent meniscal repair (4.3% vs 1%, P < .001), meniscectomy (12.1% vs 3.3%, P < .001), and ACLR (7.4% vs 2.9%, P < .001) compared with those who underwent BHMD. Multivariable analysis showed that BHMR, younger age, and lower BMI were risk factors for subsequent ipsilateral surgery. After adjusting for patient demographic and clinical characteristics, subset analysis showed that for patients aged 30 to 50 years, undergoing a BHMR versus a BHMD led to a 2.3-fold higher risk of subsequent surgery, a 5.3-fold higher risk of subsequent meniscal repair and a 3.2-fold higher risk of subsequent meniscectomy. Conclusion: BHMR was more often performed in younger patients with a lower BMI, especially during a concomitant ACLR. Patients treated with BHMR were more likely to undergo subsequent surgeries, with the likelihood decreasing with increasing age. Subset analyses showed increasing risk for subsequent surgeries with BHMR versus BHMD in the cohort consisting of patients aged 30 to 50 years.

Long-term Outcomes of Partial Meniscectomy for Degenerative Medial Meniscus Posterior Root Tears.

Background: Previous studies have demonstrated that medial meniscus posterior root tear (MMPRT) repair is superior to debridement in terms of patient-reported outcomes, rates of conversion to total knee arthroplasty (TKA), and long-term costs. Despite the known poor midterm outcomes, there is a paucity of long-term results of partial meniscectomy for degenerative MMPRTs. Purpose: To 1) evaluate long-term patient-reported and radiographic outcomes of patients who underwent partial medial meniscectomy (PMM) for MMPRTs, and 2) determine the rate of and risk factors for conversion to total knee TKA. Study Design: Case series; Level of evidence, 4. Methods: A previously identified cohort of 26 patients treated with partial meniscectomy for isolated MMPRTs between 2005 and 2013 was prospectively followed for long-term outcomes at a minimum 10-year follow-up. Patients were evaluated for International Knee Documentation Committee (IKDC) outcome score, reoperation, and conversion to TKA. Failure was defined as conversion to arthroplasty or a severely abnormal IKDC subjective score <75.4. Results: This study included 26 patients (10 men, 16 women; mean age, 54 ± 8.7 years [range, 38-71 years] at diagnosis; body mass index, 32.9 ± 5.5) who were followed for a mean of 14.0 ± 3.6 years (range, 10.1-19.6 years). At the final follow-up, 1 patient was deceased and 18 (72%) of the remaining 25 patients had progressed to TKA, with 1 (4%) patient undergoing repeat meniscectomy. The 6 (24%) patients who had not progressed to TKA or revision surgery reported a mean IKDC score of 57 ± 23. Nineteen patients underwent subsequent surgery and 5 demonstrated severely abnormal IKDC scores resulting in a clinical failure rate of 96% (24 of the 25 living patients) at a mean 14-year follow-up. Conclusion: PMM for medial meniscus posterior horn root tears demonstrated 72% progression to TKA and 96% failure according to subjective clinical outcomes at a minimum 10-year follow-up.

Validating the Use of Continuous Glucose Monitors With Nondiabetic Recreational Runners.

PURPOSE: Continuous glucose monitors (CGMs) are becoming increasingly popular among endurance athletes despite unconfirmed accuracy. We assessed the concurrent validity of the FreeStyle Libre 2 worn on 2 different sites at rest, during steady-state running, and postprandial. METHODS: Thirteen nondiabetic, well-trained recreational runners (age = 40 [8] y, maximal aerobic oxygen consumption = 46.1 [6.4] mL·kg-1·min-1) wore a CGM on the upper arm and chest while treadmill running for 30, 60, and 90 minutes at intensities corresponding to 50%, 60%, and 70% of maximal aerobic oxygen consumption, respectively. Glucose was measured by manually scanning CGMs and obtaining a finger-prick capillary blood glucose sample. Mean absolute relative difference, time in range, and continuous glucose Clarke error grid analysis were used to compare paired CGM and blood glucose readings. RESULTS: Across all intensities of steady-state running, we found a mean absolute relative difference of 13.8 (10.9) for the arm and 11.4 (9.0) for the chest. The coefficient of variation exceeded 70%. Approximately 47% of arm and 50% of chest paired glucose measurements had an absolute difference ≤10%. Continuous glucose Clarke error grid analysis indicated 99.8% (arm) and 99.6% (chest) CGM data fell in clinically acceptable zones A and B. Time-in-range analysis showed reduced accuracy at lower glucose levels. However, CGMs accurately detected trends in mean glucose readings over time. CONCLUSIONS: CGMs are not valid for point glucose monitoring but appear to be valid for monitoring glucose trends during steady-state exercise. Accuracy is similar for arm and chest. Further research is needed to determine whether CGMs can detect important events such as hypoglycemia during exercise.

Athlete Sleep Screening Questionnaire in Japanese: Adaptation and Validation Study.

CONTEXT: General screening methods for athletes are limited. This study aims to analyze the reliability and validity of the Japanese version of the athlete sleep screening questionnaire. METHODS: In total, 111 female collegiate athletes completed the initial test and retest. The independent variables included the kind of sports of the participants and their athletic level, grade (freshman, sophomore, junior, and senior), and age. The reliability of the questionnaire was assessed using Cronbach's alpha and intraclass correlation coefficients. Athletes competing in team sports and individual sports were compared to evaluate for differences. RESULTS: A total of 38.7% of athletes had moderate to severe sleep difficulty score. Their Cronbach's alpha for test and retest were .34 and .44, respectively. The intraclass correlation coefficient indicated sufficient internal consistency and test-retest validity. The mean sleep difficulty scores were 7.0 (2.3) and 6.5 (2.1) for test and retest, but no significant difference was observed between the individual and team sport athletes. Results of multivariable regression analysis revealed that having sleep and performance issues during travel was related to sleep difficulty scores (Coef 1.44, P < .01). CONCLUSIONS: Athletes of all levels have sleep disorders. The Japanese version of athlete sleep screening questionnaire has been validated with sufficient test-retest validity but has poor internal consistency. Thus, although Japanese version of the athlete sleep screening questionnaire is an appropriate questionnaire for assessing sleep disorders in athletes whose primary language is Japanese, future research is needed to optimize the questionnaire accounting for cultural variation.

The Effect of Weight Distribution in the Foot on Balance and Plantar Pressure in Female Adolescent Athletes.

BACKGROUND: It is widely reported that the weight distribution in each foot is approximately 60% in the rearfoot and 40% in the forefoot. For balance training, it is recommended to transfer some weight to the forefoot. However, it is still unclear whether fore-rear foot weightbearing ratio affects balance and plantar pressure parameters. HYPOTHESIS: There is a relationship between the forefoot weightbearing ratio and balance and plantar pressure in female adolescent athletes. STUDY DESIGN: Cross-sectional study. LEVEL OF EVIDENCE: Level 3. METHODS: A total of 91 adolescent female athletes aged between 10 and 19 years were included in the study. Weightbearing ratios of the forefoot, balance, and plantar pressure were assessed using a plantar pressure platform (FootWork, AMCube IST). In the static and stabilometric evaluation, the weightbearing ratio (%), mean and maximum plantar pressure (kPa), center of pressure (CoP) total, antero-posterior and medio-lateral sway length (cm), CoP surface area (cm2), and length over area (cm-1) were recorded. In the dynamic evaluation, the maximum pressure (kPa) acting on each foot was recorded. RESULTS: Two groups with forefoot weightbearing ratio <40% and ≥40% were compared. Maximum pressure values in static conditions, CoP anteroposterior, and total sway length were significantly different between these groups. In addition, as the amount of load transferred to the forefoot increased, CoP total and anteroposterior sway length increased postural stability. CONCLUSION: Although postural control mechanisms are quite complex, plantar pressure and postural control parameters can be varied by optimizing rear-to-fore foot weight transfer. CLINICAL RELEVANCE: This study will contribute to the development of appropriate training and rehabilitation strategies to optimize athlete performance and reduce injury risk.

Training Intensity Distribution of a 7-Day HIIT Shock Microcycle: Is Time in the "Red Zone" Crucial for Maximizing Endurance Performance? A Randomized Controlled Trial.

BACKGROUND: Various studies have shown that the type of intensity measure affects training intensity distribution (TID) computation. These conclusions arise from studies presenting data from meso- and macrocycles, while microcycles, e.g., high-intensity interval training shock microcycles (HIIT-SM) have been neglected so far. Previous literature has suggested that the time spent in the high-intensity zone, i.e., zone 3 (Z3) or the "red zone", during HIIT may be important to achieve improvements in endurance performance parameters. Therefore, this randomized controlled trial aimed to compare the TID based on running velocity (TIDV), running power (TIDP) and heart rate (TIDHR) during a 7-day HIIT-SM. Twenty-nine endurance-trained participant were allocated to a HIIT-SM consisting of 10 HIIT sessions without (HSM, n = 9) or with (HSM + LIT, n = 9) additional low-intensity training or a control group (n = 11). Moreover, we explored relationships between time spent in Z3 determined by running velocity (Z3V), running power (Z3P), heart rate (Z3HR), oxygen uptake ( Z 3 V ˙ O 2 ) and changes in endurance performance. RESULTS: Both intervention groups revealed a polarized pattern for TIDV (HSM: Z1: 38 ± 17, Z2: 16 ± 17, Z3: 46 ± 2%; HSM + LIT: Z1: 59 ± 18, Z2: 14 ± 18, Z3: 27 ± 2%) and TIDP (Z1: 50 ± 8, Z2: 14 ± 11, Z3: 36 ± 7%; Z1: 62 ± 15, Z2: 12 ± 16, Z3: 26 ± 2%), while TIDHR (Z1: 48 ± 13, Z2: 26 ± 11, Z3: 26 ± 7%; Z1: 65 ± 17, Z2: 22 ± 18, Z3: 13 ± 4%) showed a pyramidal pattern. Time in Z3HR was significantly less compared to Z3V and Z3P in both intervention groups (all p < 0.01). There was a time x intensity measure interaction for time in Z3 across the 10 HIIT sessions for HSM + LIT (p < 0.001, pη2 = 0.30). Time in Z3V and Z3P within each single HIIT session remained stable over the training period for both intervention groups. Time in Z3HR declined in HSM from the first (47%) to the last (28%) session, which was more pronounced in HSM + LIT (45% to 16%). A moderate dose-response relationship was found for time in Z3V and changes in peak power output (rs = 0.52, p = 0.028) as well as time trial performance (rs = - 0.47, p = 0.049) with no such associations regarding time in Z3P, Z3HR, and Z 3 V ˙ O 2 . CONCLUSION: The present study reveals that the type of intensity measure strongly affects TID computation during a HIIT-SM. As heart rate tends to underestimate the intensity during HIIT-SM, heart rate-based training decisions should be made cautiously. In addition, time in Z3V was most closely associated with changes in endurance performance. Thus, for evaluating a HIIT-SM, we suggest integrating a comprehensive set of intensity measures. Trial Registration Trial register: Clinicaltrials.gov, registration number: NCT05067426.