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Cadence Paradox in Cycling—Part 2: Theory and Simulation of Maximal Lactate Steady State and Carbohydrate Utilization Dependent on Cycling Cadence

Ralph Beneke and Renate M. Leithäuser

Purpose: To develop and evaluate a theory on the frequent observation that cyclists prefer cadences (RPMs) higher than those considered most economical at submaximal exercise intensities via modeling and simulation of its mathematical description. Methods: The theory combines the parabolic power-to-velocity (v) relationship, where v is defined by crank length, RPM-dependent ankle velocity, and gear ratio, RPM effects on the maximal lactate steady state (MLSS), and lactate-dependent carbohydrate oxidation (CHO). It was tested against recent experimental results of 12 healthy male recreational cyclists determining the v-dependent peak oxygen uptake (VO 2PEAKv ), MLSS (MLSS v ), corresponding power output (P MLSSv ), oxygen uptake at P MLSSv (VO 2MLSSv ), and CHO MLSSv -management at 100 versus 50 per minute, respectively. Maximum RPM (RPM MAX ) attained at minimized pedal torque was measured. RPM-specific maximum sprint power output (P MAXv ) was estimated at RPMs of 100 and 50, respectively. Results: Modeling identified that MLSS v and P MLSSv related to P MAXv (IP MLSSv ) promote CHO and that VO 2MLSSv related to VO 2PEAKv inhibits CHO. It shows that cycling at higher RPM reduces IP MLSSv . It suggests that high cycling RPMs minimize differences in the reliance on CHO at MLSS v between athletes with high versus low RPM MAX . Conclusions : The present theory-guided modeling approach is exclusively based on data routinely measured in high-performance testing. It implies a higher performance reserve above IP MLSSv at higher RPM. Cyclists may prefer high cycling RPMs because they appear to minimize differences in the reliance on CHO at MLSS v between athletes with high versus low RPM MAX .

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Effect of 6-Week Sprint Training on Long-Distance Running Performance in Highly Trained Runners

Ryosuke Ando, Chihiro Kojima, Saya Okamoto, Nobukazu Kasai, Daichi Sumi, Kenji Takao, Kazushige Goto, and Yasuhiro Suzuki

Purpose : Long-distance running performance has been reported to be associated with sprint performance in highly trained distance runners. Therefore, we hypothesized that sprint training could enhance distance running and sprint performance in long-distance runners. This study examined the effect of 6-week sprint training on long-distance running and sprint performance in highly trained distance runners. Methods : Nineteen college runners were divided into control (n = 8) and training (n = 11) groups. Participants in the training group performed 12 sprint training sessions in 6 weeks, while those in the control group performed 12 distance training sessions. Before and after the interventions, maximal oxygen uptake ( V ˙ O 2 max ), O2 cost during submaximal running (290 m·min−1 and 310 m·min−1 of running velocity), and time to exhaustion (starting at 290 m·min–1 and increased 10 m·min–1 every minute) were assessed on a treadmill. Additionally, the 100-m and 400-m sprinting times and 3000-m running time were determined on an all-weather track. Results : In the control group, no measurements significantly changed after the intervention. In the training group, the time to exhaustion, 100-m and 400-m sprinting times, and 3000-m running time improved significantly, while V ˙ O 2 max and O2 cost did not change. Conclusions : These results showed that 6-week sprint training improved both sprint and long-distance running performance in highly trained distance runners without a change in aerobic capacity. Improvement in the time to exhaustion without a change in V ˙ O 2 max suggests that the enhancement of long-distance running performance could be attributable to improved anaerobic capacity.

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Habitual Nocturnal Sleep, Napping Behavior, and Recovery Following Training and Competition in Elite Water Polo: Sex-Related Effects

Nickos G. Koutouvakis, Nickos D. Geladas, Athanasios Mouratidis, Argyris G. Toubekis, and Petros G. Botonis

Purpose: To examine nocturnal sleep patterns, napping behaviors, and subjective wellness responses of elite water polo players within an in-season week and to identify whether sleeping patterns differ between men and women. Methods: Sleep characteristics of 10 male and 17 female professional water polo players were objectively assessed during 1 week of the in-season period, including 5 training days, 1 match day, and 1 day of rest. Internal load (rating of perceived exertion × duration of training or match) was assessed 30 minutes posttraining or postmatch, and the total quality of recovery was recorded every morning. A series of multilevel models were used to analyze the data. Results: Time in bed and wake-up time were earlier on both training (P < .001) and rest days (P < .001) than on the day of the match. Internal workload did not predict any of the players’ sleeping patterns. Midday naps predicted less time in bed (P = .03) and likely less sleep time (P = .08). The total quality of recovery was predicted only by the total sleep time (P < .01). Women exhibited higher sleep efficiency (P < .001), less waking after sleep onset (P = .01), and a lower number of awakenings (P = .02) than men. Conclusions: The current results indicate that the nocturnal sleep patterns of elite water polo players are not associated with internal load and that women display better nocturnal sleep quality compared with men. As long naps interfere with nocturnal sleep, and total nocturnal sleep time predicts total quality of recovery, we suggest that athletes follow hygiene sleep strategies to facilitate adequate nocturnal sleep and next-day recovery.

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Monitoring Within-Individual Dose–Response Relationships in Professional Soccer Players: The Importance of Fitness Level

Alireza Rabbani, Giorgios Ermidis, Filipe Manuel Clemente, and Liam Anderson

Purpose: To (1) examine within-individual player dose–response associations between selected training-load measures and changes in aerobic fitness level via submaximal exercise heart rate (HRex%) and (2) measure the relationships between these dose–response associations with basal HRex% (to study the influence of fitness level on dose–response relationship). Methods: During an in-season phase, selected training-load measures including total minutes, total distance, mechanical work (the sum number of accelerations and decelerations > 3 m2), high metabolic load distance, and Edwards’ training impulse were collected via Global Positioning System and heart-rate sensors for analyzing accumulated load. A submaximal warm-up test was used repeatedly before and after 9 phases to elicit HRex% and track fitness changes at an individual level. Results: Negative to positive extensive ranges of within-individual associations were found among players for different metrics (r = −.84 to .89). The relationship between pooled HRex% (basal fitness) and dose–response correlations showed inverse very large (r = −.71) and large (r = −.65) values for accumulated weekly minutes and distance. However, moderate values were found for all other measures (r = −.35 to −.42). Conclusions: Individual players show extensive different ranges of dose–response associations with training measures. The dose–response association is influenced by players’ fitness level, and players with lower fitness levels show stronger inverse relationships with accumulated minutes and total distance.

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Swim, Strength, or Combined Programs: Effect on Health-Related Physical Fitness in Adolescents With Down Syndrome

Borja Suarez-Villadat, Kabir Sadarangani, Rui Manuel Corredeira, Mario Veiga, and Ariel Villagra

The adolescent population with Down syndrome (DS) appears to show higher levels of body fat and lower levels of cardiorespiratory fitness or muscle strength than their peers without disabilities. There is a need to create physical activity programs to improve these data. The aim of this research was to determine the effects of a 16-week swimming program, strength program, and combined program (swimming and strength training) on body composition and health-related physical fitness on adolescents with DS and to assess whether there are differences in the results of the different training programs. Forty-five adolescents (17 female and 28 male; average age 15.5 [1.53] years) with DS were recruited and randomized to three groups (swim [n = 15], strength [n = 15], and combined [n = 15]). Results showed that the swim group had significant improvements in all health-related physical fitness variables and there was an improvement in some body-composition variables (p < .05). The strength and combined groups obtained minor improvements in the variables analyzed. In summary, a 16-week swim program consisting of three sessions of 60 min is able to improve levels of body composition and health-related physical fitness in adolescents with DS. The swim training program seems to be more effective in improving body composition and health-related physical fitness than the strength or combined program. These findings could be useful in different special-education centers due to the predisposition shown by the population with DS to this sport modality.

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Predicting Injuries in Elite Female Football Players With Global-Positioning-System and Multiomics Data

Juan R. González, Alejandro Cáceres, Eva Ferrer, Laura Balagué-Dobón, Xavier Escribà-Montagut, David Sarrat-González, Guillermo Quintás, and Gil Rodas

Purpose: Injury prevention is a crucial aspect of sports, particularly in high-performance settings such as elite female football. This study aimed to develop an injury prediction model that incorporates clinical, Global-Positioning-System (GPS), and multiomics (genomics and metabolomics) data to better understand the factors associated with injury in elite female football players. Methods: We designed a prospective cohort study over 2 seasons (2019–20 and 2021–22) of noncontact injuries in 24 elite female players in the Spanish Premiership competition. We used GPS data to determine external workload, genomic data to capture genetic susceptibility, and metabolomic data to measure internal workload. Results: Forty noncontact injuries were recorded, the most frequent of which were muscle (63%) and ligament (20%) injuries. The baseline risk model included fat mass and the random effect of the player. Six genetic polymorphisms located at the DCN, ADAMTS5, ESRRB, VEGFA, and MMP1 genes were associated with injuries after adjusting for player load (P < .05). The genetic score created with these 6 variants determined groups of players with different profile risks (P = 3.1 × 10−4). Three metabolites (alanine, serotonin, and 5-hydroxy-tryptophan) correlated with injuries. The model comprising baseline variables, genetic score, and player load showed the best prediction capacity (C-index: .74). Conclusions: Our model could allow efficient, personalized interventions based on an athlete’s vulnerability. However, we emphasize the necessity for further research in female athletes with an emphasis on validation studies involving other teams and individuals. By expanding the scope of our research and incorporating diverse populations, we can bolster the generalizability and robustness of our proposed model.

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Combined Virtual-Reality- and Gym-Based Physical Activity Intervention for Children With a Developmental Disability: Effects on Physical Activity Levels, Motor Skills, and Social Skills

Hoo Kyung Lee and Jooyeon Jin

This study examined the effects of a combined virtual-reality- and gym-based physical activity (PA) program on PA levels, motor skills, and social skills of children with a developmental disability (DD). Twenty-five children with DD were randomly assigned to experimental and control groups. The intervention was conducted for 60 min, two times a week, for 12 weeks. Pre- and postintervention assessments encompassing PA levels measured via Gravity Estimator of Normal Everyday Activity, motor skills evaluated using the Test of Gross Motor Development-Third Edition, and social skills gauged via the Social Skills Rating System-Parent were conducted. Additionally, a follow-up assessment was administered to the experimental group 12 weeks postintervention. The findings unequivocally demonstrate that the combined virtual-reality- and gym-based PA program yielded significant enhancements in PA levels, motor skills, and social skills among children with DD in the experimental group. Notably, these improvements were sustained 12 weeks after the intervention. These findings may help professionals develop and implement better PA programs for children with DD.

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“Now We Can Speak”: Wheelchair Sport Participation in Areas of Armed Conflict

T.N. Kirk, Cathy McKay, and Katherine Holland

This study sought to understand the lived experiences of wheelchair basketball athletes from low- and middle-income countries of recent or current armed conflict and the meaning that they ascribed to their participation. Wheelchair basketball athletes (N = 108) from eight national teams participated in semistructured focus-group interviews. Study data were analyzed thematically using an interpretive descriptive approach. Three themes were developed: “I can do anything I want; not only basketball,” self-concept changes through sport participation; “Now they see me as a respectable person,” societal belonging through sport; and “I have motivated other disabled people,” influence on nonparticipating disabled persons. The findings indicated that participation in wheelchair sports may help disabled persons see themselves as capable individuals on the court and in aspects of daily living, perhaps even peer role models for other disabled persons in their communities and countries.

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Athletes’ Perspectives of the Classification System in Para Alpine Skiing for Those With Visual Impairment

Sara M. Douglas, Paul J. Kitchin, Andrew J. Jackson, Brendan T. Barrett, and Julie-Anne Little

This study explored the classification experiences and views of Para Alpine skiers with visual impairment. Data from 11  interviews were analyzed using reflexive thematic analysis to generate three themes: Suitability—The skiers questioned the suitability of the visual measurements, testing environment, and the information they received regarding classification; Exclusivity—Skiers felt certain aspects of the system remain exclusive due to the restrictions of sport classes and lack of the athlete voice; and (Dis)trust—Skiers felt distrust in those implementing the system and in other athletes due to intentional misrepresentation. Speculation surrounding this resulted in the skiers’ feeling doubt in their own classification. While there is not a “one size fits all” approach to classification, understanding skiers’ experiences can be a vital first step and will help to guide future research into the evolution of this sport’s classification.

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The Cognitive Function and Taekwondo-Specific Kick Performance of Taekwondo Athletes at Different Hydration Statuses

Ai-Chi Zheng, Cheng-Shiun He, Chi-Cheng Lu, Bao-Lien Hung, Kuei-Ming Chou, and Shih-Hua Fang

Purpose: Successful participation in taekwondo (TKD) requires athletes to possess quick decision-making abilities and demonstrate technical proficiency during competition. Dehydration, occurring during both training and competition, is widely recognized to have various negative effects. Methods: This study investigated the impact of different levels of dehydration on cognitive function, as measured by the Vienna Test System, and the specific performance of kicking techniques among TKD athletes. Using a randomized crossover design, 12 participants were involved in the study. Before and after 1 hour of training at 80% of maximal heart rate, participants were weighed and provided urine samples. All participants were randomly assigned to 3 different hydration conditions: the euhydrated (EUH) group had unrestricted access to fluid consumption, while the hypohydrated (HYP) and severely HYP (S-HYP) groups experienced reductions of 2.0% and 4.0% of their initial body weight, respectively. Results: The EUH group exhibited better reaction speed in reaction-time test-form S1 than the HYP and S-HYP groups. Notably, the EUH group demonstrated a significantly higher success rate in the front-side kick (EUH 98%, HYP 90%, S-HYP 88%; P < .05). However, the success rates of back roundhouse kick and free head kick were similar among the 3 statuses. Furthermore, postexercise heart rates were found to be significantly higher in the HYP and S-HYP groups compared with the EUH group. Conclusions: This study provides insight into the negative effects of dehydration on cognitive function and TKD-specific performance. It is recommended that TKD athletes maintain optimal hydration levels during training and competition to ensure optimal performance.