François Denis Desgorces

Athlete atypicity on the edge of human achievement: performances stagnate after the last peak, in 1988.

The growth law for the development of top athletes performances remains unknown in quantifiable sport events. Here we present a growth model for 41351 best performers from 70 track and field (T&F) and swimming events and detail their characteristics over the modern Olympic era. We show that 64% of T&F events no longer improved since 1993, while 47% of swimming events stagnated after 1990, prior to a second progression step starting in 2000. Since then, 100% of swimming events continued to progress. We also provide a measurement of the atypicity for the 3919 best performances (BP) of each year in every event. The secular evolution of this parameter for T&F reveals four peaks; the most recent (1988) followed by a major stagnation. This last peak may correspond to the most recent successful attempt to push forward human physiological limits. No atypicity trend is detected in swimming. The upcoming rarefaction of new records in sport may be delayed by technological innovations, themselves depending upon economical constraints.

Success and Decline: Top 10 Tennis Players Follow a Biphasic Course

INTRODUCTION The victory percentages for tennis players who entered the top 10 women and men rankings show various evolutions related to age and time since 1968. METHODS The study analyzed the careers of all top 10 players: 97 women (50,933 matches) and 144 men (92,450 matches). For each player, we describe a biphasic performance course. Two generations were compared: the first one (G1), including players who started their professional career before 1985, and the second one (G2), with players starting after 1985. RESULTS The average career length is 16.1 ± 3.8 yr for the top 10 men and 15.8 ± 4.4 yr for women. Compared with G1 players, G2 players begin earlier (women = 1.3 yr, men = 0.8 yr), but career length remains the same. An exponential model describes the time course of the victory percentage with a great similarity for both genders. Using this equation, the peak victory rate reaches 82.5% at 21.5 yr for number 1 (no. 1) women and 78.5% at 23.7 yr for no. 1 men, showing a greater precocity and earlier decline in women. Finally, the area under the curve shows a potential that is 22.8% (men) to 56.8% (women) larger for the no. 1 players as compared with all other numbers 2-10. CONCLUSIONS Tennis players in the top 10 show a biphasic career. Women reach their highest level earlier than men, consistent with their more precocious biological development. For the current generation, the peak performance tends toward a younger age than the first generation. We show how to precisely quantify and compare tennis performances using indicators that follow the trends of development and aging and demonstrate that precocity does not provide a larger victory potential.

Technology & swimming: 3 steps beyond physiology

The science of engineering materials and the development of materials science during human history have strongly evolved over the past two centuries 1,2. Other new technological fields such as particle physics, computer science, nanoscience also flourished 3 , all leading to innovations that impacted sport. Polymers and metal alloys such as carbon fibres are exemplars of materials now widely used in various disciplines 4. In 2008, polyurethane made its first appearance in swimming with the use of a new swimsuit generation. The result was a sudden improvement of performances, allowing athletes to go beyond physiological limits that have been nearly reached 5,6. This study aimed to quantify the gain provided by the three generations of swimsuits introduced in 1999, 2008, 2009 and to estimate the upcoming performance drop in 2010. Using a recently published methodology 7 , we analyzed the single best result each year for the worlds top ten swimmers from 1990 to 2009 in order to assess the sudden progression trends and quantify the total performance gain. Materials and methods We collected the best performance of the worlds top ten swimmers every year in 34 swimming events from 1963 to 2009 8-10. A total of 6790 individual performances were selected from the data spanning the 1990 – 2009 period as they present a complete measure each year. We focus here on the impact of material science in swimming by measuring the impact of the three successive generations of swimsuits on human performance and estimate the upcoming performance drop consecutive to the decision of the FINA to suspend their use. We investigate the recent evolutions of the best performers over the 1990 – 2009 period and demonstrate that three bursts of performances occurred in 2000, 2008 and 2009. The overall observed gains of these bursts exceed 2.0% for both sexes. The drop in performance that may result from this rule change may return to similar levels as seen in 1999.

Environment and scheduling effects on sprint and middle distance running performances.

Purpose Achievement of athletes’ performances is related to several factors including physiological, environmental and institutional cycles where physical characteristics are involved. The objective of this study is to analyse the performance achieved in professional sprint and middle-distance running events (100 m to 1500 m) depending on the organization of the annual calendar of track events and their environmental conditions. Methods From 2002 to 2008, all performances of the Top 50 international athletes in the 100 m to 1500 m races (men and women) are collected. The historical series of world records and the 10 best annual performances in these events, amounted to a total of 26,544 performances, are also included in the study. Results Two periods with a higher frequency of peak performances are observed. The first peak occurs around the 27.15th ±0.21 week (first week of July) and the second peak around 34.75th ±0.14 week (fourth week of August). The second peak tends to be the time of major international competitions (Olympic Games, World Championships, and European Championships) and could be characterized as an institutional moment. The first one, however, corresponds to an environmental optimum as measured by the narrowing of the temperature range at the highest performance around 23.25±3.26°C. Conclusions This is the first study to demonstrate that there are two performance peaks at a specific time of year (27th and 34th weeks) in sprint and middle distance. Both institutional and ecophysiological aspects contribute to performance in the 100 m to 1500 m best performances and define the contours of human possibilities. Sport institutions may take this into account in order to provide ideal conditions to improve the next records.

Development of a specific index to detect malnutrition in athletes: Validity in weight class or intermittent fasted athletes

Fasted or weight-category athletes manage their training under strict diet conditions that could impair the stress-recovery balance and result in acute or chronic fatigue. However, to date, no validated biomarker are available to quantify this phenomena. The aim of this study was to assess the validity of a specific index combining plasma albumin and weight change to detect nutrition-related risks of fatigue increase and under-performance in athletes experiencing particular nutritional conditions. An athletes nutrition risk index (ANRI) equation, based on data from lightweight and heavyweight rowers, was developed using relationship between plasma albumin concentrations combined to weight changes with sport performance and overtraining scores and was tested by odds ratio for failure. The accuracy and sensitivity of this former specific equation was subsequently tested on runners observing the Ramadan-fasting as well as on boxers after a short weight-loss period. Independently of training and performance, lightweight rowers presented lower nutritional parameters than heavyweight (albumin: 37.4 ± 2.7 vs 39.9 ± 1.8 g·L−1, P < 0.05; weight state: 94.5 ± 1.8 vs 99.9 ± 0.9%, P < 0.01). In lightweight, ANRI was related with overtraining score (R2 = 0.21, P < 0.01), risks for failure in competition were enhanced when ANRI increased (OR:2.5, P = 0.03). Relationship of ANRI with overtraining score tended to be also significant in runners (R2 = 0.32, P = 0.06) but not in boxers (P = 0.4). Albumin concentrations combined to weight loss appeared relevant to delineate nutrition-related risks of fatigue and/or competitive failure associated with mid-term diets (about 30 days) as observed in rowers and Ramadan-fasted runners. ANRI may benefit to athletes monitoring by delineating effects of their weight loss program.