[Course of a child born with a transfusion-transfusion syndrome from prenatal to college]. / Parcours d'un enfant né au décours d'un syndrome transfuseur-transfusé du prénatal au collège.

The literature concerning the neurocognitive evolution of children with transfusion-transfusion syndrome (TTS) is poor beyond the first year of life. It is therefore of particular interest to trace the developmental and management pathway, from the age of 18 months to 11 years, of a boy who presented with TTS in utero. This example illustrates the benefit of early multidisciplinary support and the diagnostic issues raised with the development of the child.

International Swimming League: Do Successive Events Lead to Improve Swimming Performance?

PURPOSE: To quantify the impact of successive competitions on swimming performance in world-class swimmers. METHODS: An entire data set of all events swum during a new competition named the International Swimming League was collected. A Bayesian linear mixed model has been proposed to evaluate whether a progression could be observed during the International Swimming League's successive competitions and to quantify this effect according to event, age, and gender. RESULTS: An overall progression of 0.0005 (0.0001 to 0.0010) m/s/d was observed. The daily mean progression (ie, faster performance) was twice as high for men as for women (0.0008 [0.00 to 0.0014] vs 0.0003 [-0.0003 to 0.0009] m·s-1). A tendency toward higher progression for middle distances (200 and 400 m) and for swimmers of a higher caliber (above 850 FINA [Fédération Internationale de Natation] points) was also observed. Swimmers between 23 and 26 years of age seemed to improve their swimming speed more in comparison with the other swimmers. CONCLUSIONS: This new league format, which involves several competitions in a row, seems to allow for an enhancement in swimming performance. Coaches and their support staff can now adapt their periodization plan in order to promote competition participation.

Body and Boat: Significance of Morphology on Elite Rowing Performance.

Objectives: The purpose of this study was to determine and weigh the anthropometric indicators that were associated with pacing performances for each Olympic rowing category. Methods: Between 2010 and 2015, 1,148 rowers (650 men and 498 women) participated in the finals of World Championships in each heavyweight Olympic event. They were categorized into four morphological clusters according to their height and body mass index (BMI): tall and thin (TT), tall and robust (TR), small and thin (ST), and small and robust (SR). Time and speed, were collected every 50 m for all boats in each competition. Non-parametric inferential methods were used to understand the differences in performance between morphological clusters over the entire race. After, we calculated a new indicator to determine the differences between these morphotypes within the race. Results: In this article, we determined which morphologies had a significant effect on speed for both men and women. For example, the biggest rowers were the fastest in skiff. Analysis of each 50 m demonstrated that between the four morphological categories that the TR male athletes were significantly faster than their ST counterparts between the 800 and 2,000 m of the race by 1.76% of mean speed. Furthermore, the SR were the fastest in female coxless pairs over the majority of the race. These differences in speed by morphological cluster are summarized, by race segment, for all categories and sex. Conclusion: Anthropometric factors impact pacing among rowers' categories. Coupling anthropometry and race pacing is not only helpful to understand which factors work where, but is also helpful in improving training and performance. This can help both in the recruiting of rowers for specific boats and adapting the race strategy. In future, the method used can be adapted for factors other than anthropometry. It can also be individualized to enable athletes to prepare for their race according to future competitors.

Robust Exponential Decreasing Index (REDI): adaptive and robust method for computing cumulated workload.

OBJECTIVE: The purpose of this study was to define a new index the Robust Exponential Decreasing Index (REDI), which is capable of an improved analysis of the cumulative workload. This allows for precise control of the decreasing influence of load over time. Additionally, REDI is robust to missing data that are frequently present in sport. METHODS: 200 cumulative workloads were simulated in two ways (Gaussian and uniform distributions) to test the robustness and flexibility of the REDI, as compared with classical methods (acute:chronic workload ratio and exponentially weighted moving average). Theoretical properties have been highlighted especially around the decreasing parameter. RESULTS: The REDI allows practitioners to consistently monitor load with missing data as it remains consistent even when a significant portion of the dataset is absent. Adjusting the decreasing parameter allows practitioners to choose the weight given to each daily workload. DISCUSSION: Computation of cumulative workload is not easy due to many factors (weekends, international training sessions, national selections and injuries). Several practical and theoretical drawbacks of the existing indices are discussed in the paper, especially in the context of missing data; the REDI aims to settle some of them. The decreasing parameter may be modified according to the studied sport. Further research should focus on methodology around setting this parameter. CONCLUSION: The robust and adaptable nature of the REDI is a credible alternative for computing a cumulative workload with decreasing weight over time.

Bayesian approach to quantify morphological impact on performance in international elite freestyle swimming.

OBJECTIVES: The purpose of this study was to quantify the impact of morphological characteristics on freestyle swimming performance by event and gender. DESIGN: Height, mass, body mass index (BMI) and speed data were collected for the top 100 international male and female swimmers from 50 to 1500 m freestyle events for the 2000-2014 seasons. METHODS: Several Bayesian hierarchical regressions were performed on race speed with height, mass and BMI as predictors. Posterior probability distributions were computed using Markov chain Monte Carlo algorithms. RESULTS: Regression results exhibited relationships between morphology and performance for both genders and all race distances. Height was always positively correlated with speed with a 95% probability. Conversely, mass plays a different role according to the context. Heavier profiles seem favourable on sprint distances, whereas mass becomes a handicap as distance increases. Male and female swimmers present several differences on the influence of morphology on speed, particularly about the mass. Best morphological profiles are associated with a gain of speed of 0.7%-3.0% for men and 1%-6% for women, depending on race distance. BMI has been investigated as a predictor of race speed but appears as weakly informative in this context. CONCLUSION: Morphological indicators such as height and mass strongly contribute to swimming performance from sprint to distance events, and this contribution is quantified for each race distance. These profiles may help swimming federations to detect athletes and drive them to compete in specific distances according to their morphology.

Age-Related Upper Limits in Physical Performances.

Maximal physical performances are powerful and accurate biomarkers in the understanding of age-related changes during the aging process. Previous studies have characterized age-related changes from Caenorhabditis elegans to Homo sapiens. We characterized changes in this pattern for H. sapiens, decade by decade, from 1970 to 2017. Using 286,916 performances related to age from the world's best performances in each age group, we measured the relative change of 10 different running and jumping events for both women and men. We compared the change in sexual dimorphism with age and showed that the gender gap in maximal performance regarding age increases gradually, especially after the age of 50. Between 1970 and 2017, the performances for all age groups in all events have slightly progressed. However, during the last decades, the relative progression of the best performances for all age groups has decreased in both range and frequency, suggesting that age-related maximal physical performances for H. sapiens are reaching their physiological limits.