Guro Strøm Solli

Women’s football, referring here to association football, has grown rapidly in both professionalism and popularity over the past decade, accompanied by increasing research interest (Ventaja-Cruz et...

Purpose: This study investigated the influence of including a competition-specific high-intensity endurance priming bout during warm-up on sprint time-trial (TT) performance in roller-ski skating among cross-country (XC) skiers. Methods: Twelve national-level XC skiers (2 women) completed two different warm-up protocols in counterbalanced order on two consecutive days. At each test day, the warm-ups were followed by two 1.2-km sprint TTs (TT1 and TT2) separated by 30 min of active recovery. Both warm-up protocols consisted of five laps at low to moderate intensities followed by a final lap including either a ~ 2-min high-intensity competition-specific priming (PRIM) or low-intensity exercise (TRAD). Speed and heart rate (HR) were measured continuously while rating of perceived exertion (RPE; Borg 6–20), perceived readiness and technical quality (scale 1–10) were assessed after warm-ups and TTs. After day two, participants rated how they perceived each warm-up in preparing them for performance. Results: Performance did not differ between TRAD and PRIM in TT1 (169.8 ± 18.4 vs. 169.6 ± 17.2 s, P = .885) or TT2 (166.6 ± 16.1 vs. 168.9 ± 16.8 s, P = .105). Within TRAD, performance improved in TT2 vs. TT1 (166.6 ± 16.1 vs. 169.8 ± 18.4 s, P = .008), accompanied with higher HR (175 ± 6 vs. 173 ± 6 beats·min⁻ ¹ , P = .005), RPE (18.7 ± 0.9 vs. 18.0 ± 0.9, P = .033) and perceived technical quality (7.7 ± 1.0 vs. 6.8 ± 1.4, P = .031). No differences between TTs were observed within PRIM. Athletes perceived PRIM as more beneficial in preparing them to perform than TRAD (8.0 ± 1.5 vs. 4.6 ± 1.6, P = .003). Conclusion: Including a competition-specific high-intensity priming bout during warm-up did not enhance sprint TT performance compared to a traditional warm-up but was perceived as more beneficial in preparing the skiers to perform.

Purpose : This article offers a structured overview of published case studies involving elite and world-class female Olympic athletes, highlighting the unique insights these studies provide into training characteristics, physiology, performance, and female-specific factors. Methods : Four databases were systematically searched for peer-reviewed case studies involving tiers 4 to 5 female Olympic athletes reporting individual-level data on training, physiological, and/or performance characteristics. Results : Thirty-eight studies describing 54 elite and world-class female athletes from 18 countries and 19 Olympic sports met the inclusion criteria. Most studies were published after 2017 (68%), originated from Europe (58%), and involved endurance sports (81%). Fifteen studies examined long-term athlete development, with observation periods ranging from 4 to 26 years. Fourteen studies reported annual training and physiological characteristics across 10 sports including training volume, intensity distribution, periodization, and physiological profiling. Four studies examined altitude training, 8 addressed competition demands, tapering, and precompetition strategies, and 8 focused on female-specific physiology, health, and performance, including energy availability, menstrual function, hormonal cycle monitoring and pregnancy, and postpartum return to sport. Conclusion : Case studies provide unique athlete-centered insights into the complex interactions between training, physiology, health, and performance in elite female athletes. Collectively, they demonstrate that pathways to world-class performance are highly individualized, while generating hypotheses that complement group-based research. Future case studies should prioritize underrepresented sports, geographical regions, and female-specific topics to expand the diversity of performance environments and athlete populations represented in the literature.

Purpose : To provide insights into the key practices driving the evolution of endurance training and performance. Methods : A total of 78 world-class coaches (73 men, 5 women), representing 14 endurance sports, and 18 nations, participated in a digital survey comprising open-ended questions about recent trends and projected future developments. Results : Qualitative thematic analysis revealed 8 key drivers of change: (1) individualized and sport-specific training strategies, (2) precision in training execution, (3) load-management procedures, (4) strategic use of environmental stressors, (5) optimized nutrition, (6) holistic recovery practices, (7) health and injury prevention, and (8) equipment and technology-driven innovation. To provide a clearer conceptual framework, these themes were grouped into 3 overarching categories: training methodologies (themes 1–4), recovery and health management (themes 5–7), and technological innovation (theme 8). Conclusions : World-class endurance coaches describe a continuing shift toward more individualized training strategies, characterized by detailed sport-specific considerations, training plans aligned with physiological profiles, greater precision in training execution, refined load management, and strategic use of environmental stressors. In this context, advanced monitoring technologies are viewed as essential for optimizing training adaptations while minimizing the risk of maladaptation and injury. Coaches also emphasized the importance of enhanced health and recovery strategies to support training adaptations, including sleep quality, stress management, life balance, and targeted nutritional interventions, particularly carbohydrate availability. Finally, the rapid development of new equipment and technologies is transforming training and coaching practices, thereby contributing to improved endurance performance.

Purpose : Sport-physiology and -performance research often relies on group designs that compare experimental and control groups and/or preintervention and postintervention results. This commentary highlights the key elements of a high-quality case study and provides clear guidelines for readers and authors of the International Journal of Sports Physiology and Performance . We propose 4 essential components. First, case studies should offer relevant and original insights by tackling novel issues and defining a clear purpose. Second, they must employ rigorous methodology, encompassing careful participant selection, comprehensive data collection from diverse sources (eg, interviews, surveys, physiological tests, training diaries, competition data), and deliberate data analysis that explicitly addresses factors influencing performance changes. Third, they should be well structured and engagingly presented to reach both academic and practical audiences. Finally, bridging the science–practice gap is vital, requiring and strengthening collaboration between researchers and practitioners to enable data-driven decision making and spark new hypotheses. Conclusions : Although case studies traditionally rank low in the research evidence hierarchy, high-quality examples can significantly bridge the gap between research and practice. By working closely with the sporting community and strategically sharing findings, case studies can enhance evidence-based training strategies and amplify the real-world impact of sport science.

Purpose : To investigate the effects of a tailored educational session about the menstrual cycle (MC) and hormonal contraceptives (HCs) on perceived knowledge, knowledge satisfaction, communication, and the coach–athlete relationship among junior endurance athletes and their coaches. Methods : Junior female cross-country skiers and biathletes (n = 36) and their coaches (n = 12) completed 2 questionnaires within an 8-week interval (PRE–POST). After 2 weeks, the intervention group (20 athletes and 6 coaches) participated in a tailored educational session designed to enhance their knowledge about the MC and HCs. The control group (16 athletes and 6 coaches) received no education on this topic. Results : Athletes and coaches in the intervention group experienced significant PRE–POST increases in perceived knowledge (estimate = 1.28, P = .002) and satisfaction (estimate = 1.20, P < .001) with their knowledge of the MC and HCs compared to the control group. Coaches had higher perceived knowledge (estimate = 1.45, P = .003) and satisfaction (estimate = 0.83, P = .041) with their knowledge of the MC than athletes. The intervention improved the degree of communication with peers (estimate = 1.02, P = .013) but not with the other role (ie, athletes’ communication with coaches and vice versa; estimate = 0.12, P = .833). In addition, it improved perceived ease of communication (estimate = 0.93, P = .003). The intervention did not seem to affect the coach–athlete relationship ( P > .005). Conclusion : The educational session resulted in promising effects on perceived knowledge and satisfaction with athletes’ and coaches’ knowledge of the MC/HCs, while also facilitating communication among athletes. Future studies should focus on implementing and evaluating more longitudinal interventions with larger sample sizes.

Purpose : To compare annual training characteristics and periodization of physical training and shooting between junior, developmental, and elite-level biathletes. Methods : A retrospective cross-sectional design was used to compare 24 biathletes (12 women) equally distributed across the Norwegian junior (JUN, 20.3 [1.0] y), developmental (DEV, 24.3 [1.3] y), and elite (ELITE, 26.2 [1.6] y) national teams. Inclusion criteria were having a top-10 performance in Junior World Championships, International Biathlon Union Cup, and International Biathlon Union World Cup for the 3 groups, respectively. Training data from the 2021–22 season were categorized by endurance intensity (low- [LIT], moderate-, and high-intensity training), exercise mode, strength, and speed. Shooting data included shots fired during rest, LIT, moderate-intensity training, high-intensity training, and competitions. Results : Total annual physical training volume was 21% and 14% higher in ELITE (703 [53] h) than JUN (582 [112] h) and DEV (615 [86] h, both P < .05), respectively, mainly due to more LIT and moderate-intensity training (both P < .05). ELITE and DEV performed 37% and 25% more shots than JUN (12,779 [1757] and 11,638 [1782], respectively, vs 9301 [2042]), mainly caused by more shots during LIT (both P < .05). The only differences in annual periodization of physical training and shooting between developmental levels were that ELITE performed higher physical training volumes (17.2 [1.5] vs 13.3 [3.6] h/wk) and fired more shots (377 [70] vs 199 [73] shots/wk) during the general preparation period compared with JUN (both P < .05). Conclusions : This study provides novel reference data on the training characteristics of high-level biathletes across developmental levels, demonstrating that higher volumes of both physical and shooting-specific training distinguish elite senior athletes from their junior counterparts. However, individual year-to-year progression patterns should be explored in future longitudinal studies.

The aims of the current study were to (1) report the prevalence of hormonal contraceptive (HC) use among Norwegian women across different training categories and age groups; (2) compare the frequency and severity of cycle‐related symptoms across differing training categories and age groups; and (3) describe the bleeding pattern and prevalence of menstrual disorder/disturbances among non‐HC users. A sample of 2059 Norwegian women completed a survey reporting: weekly training volume; current HC usage, type, and reasons for use; cycle‐related symptom frequency and severity; and the prevalence of menstrual disorders/disturbances. Respondents were categorized by age (youth: 13–20; young adults: 21–30; older adults: 31–50 years) and training category (minimal: 0; low: < 5; moderate: 5–9; high: ≥ 9 h·week⁻¹). Half (51.6%) of respondents reported current HC usage, predominantly long‐acting reversible contraception or combined oral contraceptives. Young adults had the highest prevalence of HC use (62.7%) compared to youth (48.4%) and older adults (43.8%), although no differences in usage were seen across training categories. HC users reported fewer and less severe cycle‐related symptoms compared to non‐users. A third (30.8%) of non‐HC users had experienced a menstrual disorder/disturbance, with no significant differences observed across training categories or age groups. In conclusion, HC use is widespread among Norwegian women, with no differences between training categories. This similar HC prevalence suggests that HC research conducted in female cohorts may be generalizable, independent of training category. However, attention should be paid to participants' age due to differences in HC use between age groups.

Purpose: To compare the frequency and severity of self-perceived negative symptoms associated with the menstrual cycle or hormonal-contraceptive (HC) cycle between (1) HC users and non–HC users and (2) different competition levels. An additional aim was to describe the rate and type of HC use and prevalence of potential menstrual-cycle disturbances in female team handball players. Methods: A total of 136 team handball players, competing at different levels (international, 48; national, 52; local/regional, 36), completed a cross-sectional survey regarding self-reported negative cycle-related symptom frequency and severity, perceived influence on training/competition performance, menstrual function, and current and/or past HC use. Results: Although most players regularly experienced negative cycle-related symptoms, non–HC users reported more frequent and severe cramps (P = .001 to .026), as well as a higher occurrence of fatigue and skin problems (P = .019 to .045), compared with HC users. Negative symptoms such as fatigue were more common and severe for local/regional-level players compared with players at higher (international) competition levels (P = .006–.046). Half (47%) of the players currently used HC, primarily long-acting reversible contraceptives (52%), as well as the combined oral (33%) or progestin-only pill (14%). Notably, only 2% of players altered their training in response to negative cycle-related symptoms, despite 41% perceiving that these symptoms interfered with training quality and athletic performance. Conclusions: Negative cycle-related symptoms are common among team handball players, regardless of HC use, and are perceived by many players to adversely influence their athletic performance.