Friedemann Schwenkreis

Dr. Friedemann Schwenkreis


Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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7 May 2025 in Sports Medicine - Open
Verified
Journal Article
Open access
PDF file
EKElisabeth Maria Kirschbaum
Elisabeth Maria Kirschbaum
KFKatharina Fischer
Katharina Fischer
DSDorothee Speiser
Dorothee Speiser
FLFranziska Lautenbach
Franziska Lautenbach
FSFriedemann Schwenkreis
Friedemann Schwenkreis
KLKirsten Legerlotz
Kirsten Legerlotz
Background: While a regular menstrual cycle is an indicator of good health, menstrual dysfunction (MD) and wrong beliefs regarding hormonal contraceptives (HC) are quite common among elite female athletes and threaten their health. This study aimed to (1) identify the prevalence of current and lifetime MD in various sports disciplines, (2) investigate variables that are associated with the prevalence of MD, (3) study the current practice of HC use among elite German female athletes. Methods: 584 German elite female athletes (mean 20.7 ± 4.9 years) from 64 different sports completed an online questionnaire to assess gynecological health characteristics, history of MD, and the use of HC. Results: Sixty-nine percent of athletes not using HC reported a regular menstrual cycle, while oligomenorrhea was currently reported in 13%, secondary amenorrhea in 8%, primary amenorrhea in 2% and polymenorrhea in 8%. The current prevalence of primary amenorrhea differed between sports disciplines (p = 0.002), while oligomenorrhea (p = 0.828) and secondary amenorrhea (p = 0.848) did not. The lifetime prevalence of primary amenorrhea (10%) and oligomenorrhea (74%) differed significantly between sports disciplines (p < 0.001 and p = 0.001), while secondary amenorrhea (40%) did not (p = 0.298). The current and lifetime prevalence of primary amenorrhea was higher in aesthetic sports disciplines, while the lifetime prevalence of oligomenorrhea was higher in endurance disciplines. Factors associated with lower prevalences of MD were menstrual cycle tracking (p < 0.001), higher gynecological age (p < 0.001), regular gynecological health screenings (p = 0.008), and a diagnosed eating disorder (p = 0.037). Twenty-nine percent of these elite athletes used HC, of whom 15% claimed to use HC as a treatment for MD. Conclusion: Elite female athletes from a variety of sports disciplines, not just from endurance and aesthetic sports, are at high risk of developing MD. Given the high percentage of athletes using HC to treat MD, educating athletes, coaches, others from the support team and parents about the risk and prevention of MD and the effects of HC in the context of elite sports may improve gynecological health among elite athletes.




1 March 2026 in International Journal of Sports Physiology and Performance
Verified
Journal Article
Closed access
AHAlexander-Stephan Henze
Alexander-Stephan Henze
LMLynn Matits
Lynn Matits
FSFriedemann Schwenkreis
Friedemann Schwenkreis
DSDaniel Sieger
Daniel Sieger
HDHannes Degenhardt
Hannes Degenhardt
JKJohannes Kirsten
Johannes Kirsten
Purpose : To examine the relationship between well-being and match performance in elite team handball. Methods : Eighteen male handball players competing in the first German national league were investigated over an entire season (September 2023 to June 2024). On matchdays, well-being was assessed in the morning with a customized, nonvalidated questionnaire, consisting of three 5-point Likert-type items (“physical condition,” “mental freshness and energy level,” and “sleep and recovery”). Team performance was evaluated based on the points scored in each match. Individual performance was assessed using a novel approach with 4 data aggregates of positive and negative offense and defense playing actions, on which the Handball Performance Index (version 2.0; official individual match performance metric in the Handball-Bundesliga) is based. Cumulative link models for ordinal regression and linear mixed-effects models were used to analyze the relationship between well-being, match type (home vs away), and both team and individual performance. Results : “Sleep and recovery” ratings were lower prior to away matches ( p < .001). Interaction effects revealed that physical and mental well-being influenced match outcomes (“physical condition” × “match type”: P = .019, “mental freshness and energy level” × “match type”: P = .001), with a weaker effect in away matches. No significant effects were observed on individual performance metrics. Conclusions : This study is the first to investigate the complex relationship between athlete well-being, contextual factors (home vs away matches), and performance in elite team handball. However, it is important to consider the study’s limitations regarding validity, applicability, and transferability.