# Sport participation, weight status, and physical fitness in French adolescents

Jérémy Vanhelst, Anne Le Cunuder, Luc Léger, Martine Duclos, Daniel Mercier, François Carré

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Jérémy Vanhelst, Anne Le Cunuder, Luc Léger, Martine Duclos, Daniel Mercier, et al. Sport participation, weight status, and physical fitness in French adolescents. 2024. hal-04717606

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Sport participation, weight status and physical fitness in French adolescents

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Jérémy Vanhelst¹, Anne Le Cunuder², Luc Léger³, Martine Duclos⁴,⁵, Daniel Mercier⁶,
François Carré⁷

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¹Université Sorbonne Paris Nord and Université Paris Cité, INSERM, INRAE, CNAM, Center of Research in Epidemiology and StatisticS (CRESS), Nutritional Epidemiology Research Team (EREN), F-93017 Bobigny, France.

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²Laboratory Movement, Sport and Health Sciences, UFR STAPS, University of Rennes 2, France.

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³École de kinésiologie et des Sciences de l'activité physique, Université de Montréal, Montréal, Québec, Canada.

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⁴International Research Chair Health in Motion, Clermont Auvergne University Foundation, 63000, Clermont-Ferrand, France

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⁵University Hospital Clermont-Ferrand, Department of Sport Medicine and Functional Exploration, Clermont Auvergne University, INRAE, UNH, F-63000 Clermont-Ferrand, France

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⁶Université Grenoble-Alpes, Grenoble, France.

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⁷LTSI INSERM, U1099, University of Rennes 1, and Department of Sport Medicine, Pontchaillou Hospital, Rennes, France.

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Address correspondence to:

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Jérémy Vanhelst

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Equipe de Recherche en Epidémiologie Nutritionnelle (EREN)

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UMR U1153 Inserm / U1125 Inrae / Cnam / Université Sorbonne Paris Nord

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Centre de Recherche en Epidémiologie et Statistiques - Université Paris Cité (CRESS)

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74 rue Marcel Cachin,

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F-93017 Bobigny Cedex France

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E-mail: jeremy.vanhelst@eren.smbh.univ-paris13.fr
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**Background:** The primary objective of this study was to investigate the associations between sport participation and weight status with physical fitness among French adolescents. The secondary aim was to establish sex- and age-specific physical fitness percentiles for French adolescents.

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**Methods:** The sample comprised 8084 adolescents (4126 boys, 3958 girls), aged 10–14 years. Participants were tested on cardiorespiratory fitness and muscular strength using the following tests: 20-m shuttle run test and handgrip strength test. A questionnaire on organized sport participation was completed.

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**Results:** Physical fitness levels were better in boys (*P* < 0.005). Handgrip strength increased with age whereas 20-m shuttle run performance decreased with age. Overweight and obese adolescents had significantly lower cardiorespiratory fitness levels than their normal-weight peers (*P* < 0.005), whereas normal-weight adolescents had lower cardiorespiratory fitness than thin adolescents (*P* < 0.005). Sport participation was higher for boys (57.2% boys vs. 52.8% girls) (*P* < 0.001). Adolescents who participated in at least one organized sport (either through a club or at school) were fitter than those who did not participate in organized sports (*P* < 0.005).

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**Conclusions:** Adolescents who engaged in organized sports were more active and physically fit than those who did not participate. The fitness benefits of club sports are greater than those provided by school-based sports, highlighting the potential of sports clubs as a key setting for promoting health.

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**Keywords:** Fitness, youth, sport participation.

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56 INTRODUCTION

57 Health-related fitness encompasses several components such as cardiorespiratory fitness
58 (also known as aerobic fitness or cardiorespiratory endurance), musculoskeletal fitness
59 (muscular strength, power, endurance, and flexibility), and body composition (body mass
60 index (BMI), and waist circumference) [1]. Given the broad spectrum of health-related fitness
61 components, understanding their specific contributions to overall health is crucial for effective
62 monitoring and intervention.

63 Over the years, it has been widely demonstrated that physical fitness is a strong marker of
64 health in children and adolescents [1, 2]. Indeed, a review study reported that physical fitness
65 is linked to numerous health benefits, including a reduced risk of chronic diseases and
66 premature death [2]. Among the different components of physical fitness, cardiorespiratory
67 fitness and muscular strength have shown the strongest and most consistent associations
68 with health in children and adolescents, and are also a strong predictor for future health in
69 adulthood [3, 4]. In addition, studies indicate that a high level of cardiorespiratory fitness and
70 muscular strength has positive effects on mental health [2, 5]. Recent studies based on large
71 samples have reinforced earlier findings, indicating that low cardiorespiratory fitness and
72 muscular strength during childhood and adolescence are associated with increased risks of
73 early all-cause and cause-specific mortality, including cardiovascular diseases and cancer
74 [6-9]. These two components of physical fitness in childhood are crucial predictors of future
75 disability in adulthood, with a study showing that muscular weakness and a combination of
76 poor muscular strength with low cardiorespiratory fitness during adolescence are strongly
77 associated with an increased risk of disability later in life [10]. Because cardiorespiratory
78 fitness and muscular strength are important indicators of current and future health, it is
79 important to assess them regularly in children and adolescents.

80 The last French Report Card on Physical Activity and Sedentary Behaviors in Children and
81 Youth (2022) emphasized a lack of fitness data and the need to develop nationwide
82 programmes to measure the physical fitness levels of youths [11]. In addition, a recent study
83 showed a large decline in cardiorespiratory fitness levels among French children and
84 adolescents since 1999 [12]. In this context, improving our understanding of factors
85 associated with physical fitness outcomes is much needed for designing present and future
86 national health improvement policies. The primary objective of this study was to investigate
87 the associations between sport participation and weight status with physical fitness among
88 French adolescents. The secondary aim was to establish sex- and age-specific physical
89 fitness percentiles for French adolescents.
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## METHODS

### Study design

The study was conducted between September and October 2022 in three regions of France (Hauts-de-France, Brittany, Auvergne-Rhône-Alpes). All schools in these regions were invited to participate. The decision to join the study was made by each school's principal and Physical Education (PE) teacher. If both agreed, the adolescents were invited to take part in the study. Written informed consent was obtained from both the adolescents and their parents. The study received approval from the local ethics committee (Centre Hospitalier Universitaire de Rennes, n° 21.115), and all procedures adhered to the ethical standards of the 1975 Helsinki Declaration, as revised in 2008.

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### Measures

#### Participant characteristics

Sex (male/female) was self-reported. Body weight was measured to the nearest 0.1 kg using an electronic scale, with participants wearing light clothing and no shoes. Height was recorded without shoes to the nearest 0.1 cm using a standard physician's scale. Then, the BMI was calculated as weight/height² (kg/m²). Nutritional status was evaluated using the International Obesity Task Force scale [13].

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#### Physical fitness

The health-related physical fitness components were assessed using two tests from two batteries of well-validated physical fitness tests, which assessed cardiorespiratory fitness and upper limbs muscular strength [14, 15]. To ensure strict standardization in physical fitness measurements across different schools, several web-based training sessions were conducted by a study investigator for the PE teachers. These sessions were recorded, allowing PE teachers to review the material as needed. The instructions provided to the adolescents for each test were standardized across all schools. In addition, a smartphone application (METs-Up Pro Navette®) was developed to reinforce the testing procedures and guide data collection. Each PE teacher received a unique account for this application, through which they recorded the data. The entire dataset was audited, and aberrant data were excluded.

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#### Cardiorespiratory fitness (CRF)

CRF was assessed using a modified version of the original 20-m shuttle run test (20-m SRT) developed by Leger et al. [16], the PREFIT (FITness testing in PREschool children) [17]. In this test, adolescents continuously ran back and forth between two lines set 20 metres apart,
following the pace set by audio signals from a pre-recorded CD. The test started at a speed of 6.5 km/h, increasing by 0.5 km/h every minute. Adolescents were instructed to run in a straight line, pivot on reaching each line, and maintain their pace in sync with the audio signals. They were verbally encouraged to run as long as possible. The test finished when adolescents failed to reach the line in sync with the audio signals on two consecutive attempts, or when they voluntarily stopped due to fatigue. The last fully or half-completed stage was recorded, with the corresponding speed used for statistical analysis. The PREFIT allows a feasible, reliable, and valid assessment of CRF among pre-schoolers aged 5–6 years [14, 18]. To estimate the number of shuttles for the 20-m SRT using the original protocol, we applied a linear regression as recommended by Mora-Gonzalez [18]. The formula used was $Y = 0.535X - 1.685$, where Y represents the shuttles of the original protocol and X represents the shuttles from the PREFIT protocol [18].

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## Muscular strength

Upper body muscular strength was assessed using the handgrip test [15]. The Camry digital handgrip dynamometer with an adjustable grip to account for varying hand sizes (EH101; Zhongshan Camry Electronic Co. Ltd., Zhongshan, China) was used. This digital dynamometer is a cost-effective and valid alternative to the gold standard Jamar® hydraulic handgrip dynamometer [19, 20]. It measures isometric grip strength ranging from 0 to 90 kg. During the test, adolescents stood with the arm fully extended at a 30° angle from their trunk to prevent any other body part from contacting the dynamometer, except the hand being measured. The radioulnar and wrist joints were maintained in a neutral position to ensure accurate and consistent measurements. They were instructed to squeeze the dynamometer gradually and continuously for 2 to 3 seconds. Each hand was tested twice, with a one-minute rest between trials, and the order of testing each hand was randomized. For each hand, the maximum score expressed in kilograms (absolute value) was recorded. No verbal encouragement was provided during the test to avoid any external influence on the participants' performance. The handgrip test shows a high-to-very-high construct validity and reliability, and negligible test-retest learning and fatigue effects in adolescents [15, 21–23].

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## Sport participation

Data on sport participation were collected through two questions asked of the adolescents. Before physical fitness tests, PE teachers asked the following questions to adolescents: 'Are you a member of an organized sports club outside of school?' and 'Are you a member of an organized sports club at school?'

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## Statistical analysis
Continuous variables are presented as mean (standard deviation, SD), whereas categorical variables are expressed as frequency (percentage). The normality of distributions was evaluated using histograms and the Shapiro-Wilk test. Sex differences in participant characteristics were analysed using a t test for continuous variables and a chi-squared test for categorical variables. Comparisons of physical fitness, weight status, and sports participation were conducted using a one-way analysis of variance. Pairwise post hoc comparisons were carried out using linear contrasts, with a Bonferroni correction applied for multiple comparisons. Percentile values, including the 5th, 10th, 20th, 30th, 40th, 50th, 60th, 70th, 80th, 90th, and 95th percentiles of physical fitness measures for French adolescents, were calculated by age and stratified by sex using the generalized additive model for location, scale, and shape (GAMLSS). The GAMLSS package (version 4.2-7) within the R statistical software (version 3.2.1) was used for these analyses.

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## 177 RESULTS

In total, 9022 adolescents (4428 girls and 4593 boys, mean age 11.25 ± 0.42 years) participated in the study. From the total population, 938 adolescents (467 boys and 471 girls) with missing or incomplete data on anthropometric measurements, age, or non-physical fitness measurements were excluded, resulting in a study sample of 8084 participants (Figure S1). Because of the small sample size for 13-year-old subjects (n = 62), the percentile values were reported only for 10-12-year-old subjects (n = 8022). Physical fitness measurements are displayed by sex in Table 1. Overall, physical fitness performances were better in boys (*P* < 0.005, Table 1). Handgrip strength increased with age whereas 20-m shuttle run performance decreased with age. Sport participation was higher for boys (57.2% boys vs. 52.8% girls) (*P* < 0.001; Table 1).

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Insert Table 1.

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Physical fitness according to weight status in boys and girls is presented in Table 2. Scores in the 20-m SRT were better for adolescents with a normal weight than for overweight and obese adolescents (*P* < 0.005; Table 2). By contrast, normal-weight adolescents had significantly lower performance in 20-m SRT than thin adolescents (*P* < 0.005; Table 2). Overweight and obese adolescents had significantly better results in handgrip strength than their normal or thin counterparts (*P* < 0.005; Table 2) whereas the normal-weight adolescents had better scores than thin adolescents (*P* < 0.005; Table 2). Results are similar when stratified by sex.

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Insert Table 2.
As shown by the data in Table 3, adolescents with at least one organized sport participation (club or in school) had better performances in 20-m SRT than non-organized sport participation participants (*P* < 0.005; Table 3). In other terms, on average, adolescents participating in organized school and club sport ran two stages more on the SRT than adolescents reporting no organized sport participation. Results are similar when stratified by sex. No difference was found for upper muscular strength (Table 3).

Insert Table 3.

Sex- and age-specific percentile values (P5, P10, P20, P30, P40, P50, P60, P70, P80, P90, P95) for physical fitness measures are described in Tables 4, 5.

Insert Tables 4, 5.

Beyond the well-established health benefits of high physical fitness, the decline in physical fitness among youth is well documented [12, 24, 25]. A meta-analysis has shown that cardiorespiratory fitness levels in French children and adolescents have declined over recent decades, with a decrease of 2.7 ml.kg⁻¹.min⁻¹, or 5.7% per decade [24]. A recent study has further corroborated this decline over the past two decades [12]. Therefore, it is crucial to continue monitoring physical fitness levels in French youth and to investigate the role of individual and environmental factors in relation to physical fitness.

Our first finding showed differences in physical fitness levels according to sex. Boys showed better performances for 20-m SRT and handgrip strength than girls. These data concur with previous studies conducted in France and other countries in Europe or on other continents [26–30]. Indeed, two previous large French cohort studies showed that physical fitness levels were better in boys than in girls, except for agility and flexibility [26, 31]. From these two studies, one study showed a difference of 1.4 stages completed (6.3 vs. 4.9 for boys and girls, respectively), using the original 20-m shuttle run [26]). In our present study, the mean difference is similar (7.7 vs. 6.4). The differences between boys and girls are associated with developmental changes in body composition during adolescence, driven by puberty and related hormonal changes, generally beginning around age 11 years for girls and 12 years for boys, with significant individual variations [32]. Daily physical activity is also a factor that
could explain this difference in physical fitness levels. Previous studies have shown that a high daily physical activity or meeting physical activity guidelines in youth was associated with better physical fitness levels [33–35]. It is widely acknowledged that physical activity levels are lower in girls than in boys [36, 37]. Recently, Verdot et al. (2022) demonstrated, in a large sample of French youth, a substantial and significant disparity between boys and girls in meeting physical activity guidelines, with 51% and 33%, respectively [38]. Hence, the lower level of physical activity among girls, along with a decreased percentage of French girls meeting physical activity guidelines, might account for the discrepancy in physical fitness between boys and girls in our study.

Regarding weight status differences, normal-weight adolescents (both boys and girls) have significantly higher performances in 20-m SRT than their overweight and obese counterparts (*P* < 0.005). This has been extensively studied and our data support previous findings on the relationship between weight excess and low physical fitness levels [39–41]. However, our results should be interpreted with caution because the data are only presented with body weight, without considering body composition (i.e. fat-free mass). Indeed, Goran et al. demonstrated that cardiorespiratory fitness expressed relative to fat-free mass was not significantly different between normal-weight and obese children [42]. As we found in our study, several studies have reported a positive association between BMI and muscular strength assessed using the handgrip test [39, 43]. However, the relationship is reversed when expressed relative to body weight. Our study also showed that performances in 20-m SRT are better among thin adolescents than among those with a normal weight status (*P* < 0.005). The SRT may be considered weight dependent. Indeed, thin adolescents with a low weight may have a lower energy expenditure at the same speed than adolescents with normal weight status. Therefore, thin adolescents might have an advantage in this type of test over normal-weight adolescents, which could explain their better performance in cardiorespiratory fitness tests.

Another outcome found from our study was the positive association between organized sport club participation (club or school sport) and physical fitness levels. Our results are consistent with previous studies performed in other countries [44–46]. In addition to the benefits of physical fitness, studies have also shown that sport participation was associated with lower fat mass and BMI, higher daily physical activity levels and a lower time spent in sedentary activities [47–49]. However, participation in organized sports does not ensure that adolescents meet physical activity guidelines (60 minutes daily of moderate to vigorous activity) [50]. Sports participation can also substantially influence weight status. Drake et al. showed that the prevalence of obesity would decrease by approximately 26% if all
adolescents played on at least two sports teams per year [51]. Unfortunately, the 2022 French Report Card on Physical Activity and Sedentary Behaviors in Children and Youth highlighted a 4% decrease between 2019 and 2022 in the enrolment of French youth in sports clubs [11]. This highlights the need to persist and enhance ongoing policy initiatives aimed at broadening access to and participation in sports clubs/associations.

In the present study, French adolescents demonstrated lower performance in the 20-m SRT than recently published international and European norms [27, 52]. Both boys and girls have had 20-m SRT performance around the 30th percentile when compared with these international and European standards. By contrast, their results for muscular strength were better, with both boys and girls scoring around the 60th percentile of the European norms, indicating above-average muscular strength for both sexes. In light of these findings, targeted actions are necessary to improve physical fitness among adolescents in France. Public health strategies should be implemented to address these gaps and promote better overall fitness among the youth.

Given the absence of reference standards of upper muscular strength in French adolescents, results from our study showing sex- and age-specific normative values for using the handgrip test are relevant [4, 8, 10, 53]. These references are necessary for screening, monitoring, and making a national standard or surveillance in comparison with their counterparts [54, 55]. We encourage French investigators (e.g. healthcare practitioners, PE teachers, researchers, and sport coaches) to use these new normative data when they assess the physical fitness levels of adolescents to identify those with a low physical fitness status.

The main strengths include data analysis in a large sample of adolescents derived from three administrative regions in France with sex-specific information, with the use of standardized procedures and the rigorous methodology to assess physical fitness (web-based training sessions and smartphone application for the procedures of tests and how to collect data). These strengths improve the applicability and implementation of our findings and the statistical robustness of the results. Another strength is establishing sex and age percentiles for both sexes due to the widely known impact of age and sex on physical fitness levels. The last strength recognized is the use of two validated tests to assess cardiorespiratory and muscular fitness, widely used at the European/international level. Our study also presents some limitations. The main limitation concerns the design of the study. Indeed, our cross-sectional data are likely to underestimate within-individual age-related changes. Although the present data were derived from a large sample, this study did not use a stratified sample design with a narrow age demographic. Therefore, it is not possible to assume that the studied cohort is fully representative of the French adolescent population. Lastly, the use of
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the 20-m shuttle run from the PREFIT battery proposed for children aged 5–6 years, thus not
appropriate for the age range of our study sample.

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In conclusion, our findings suggest that adolescents in France who engaged in organized
sport were more physically fit than those who did not participate. While these results highlight
the potential benefits of club sports over school-based sports in promoting physical fitness,
the cross-sectional nature of this study limits the ability to establish causality. Therefore,
these findings should be interpreted with caution, and further longitudinal research is needed
to confirm the causal relationships. Nevertheless, our result suggests that sports clubs may
serve as a valuable setting for promoting adolescent health. Developing policies aimed at
increasing physical education and sports in schools and colleges, as well as promoting
access to organized sports clubs, could significantly enhance the cardiorespiratory fitness of
adolescents, thereby improving their overall health. However, to achieve these goals,
targeted strategies are essential, particularly for increasing the participation of overweight or
obese adolescents and girls in organized sports. These strategies should be tailored to meet
the specific needs of these groups to ensure broader participation and better health
outcomes.

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Acknowledgments

The authors sincerely thank every teacher and children involved in this study.

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Conflict of interest

The remaining authors state no conflict of interest.

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Authors contributions

Jérémy Vanhelst, Daniel Mercier, Martine Duclos, Luc Léger and François Carré conducted
the initial analyses and drafted the initial manuscript. Anne Le Cunuder conducted statistical
analysis and drafted the initial manuscript. François Carré and Daniel Mercier designed data
collection instruments, coordinated and supervised data collection and reviewed the
manuscript. All authors approved the final manuscript as submitted and agree to be
accountable for all aspects of the work.

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Funding

There is no funding for this study.
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54. Tomkinson GR, Carver KD, Atkinson F, et al (2018) European normative values for physical fitness in children and adolescents aged 9–17 years: results from 2 779 165 Eurofit performances representing 30 countries. Br J Sports Med 52:1445–1456.
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528

55. Kułaga Z, Świąder-Leśniak A, Kotowska A, Litwin M (2023) Population-based references for waist and hip circumferences, waist-to-hip and waist-to-height ratios for children and adolescents, and evaluation of their predictive ability. Eur J Pediatr 182:3217–3229. https://doi.org/10.1007/s00431-023-05001-4

529
530 **Statements and Declarations**

531

532 **Conflict of interest**

533 The remaining authors state no conflict of interest.

534 **Funding**

535 There is not support for this research.

536 **Authors contributions**

537 Jérémy Vanhelst, Daniel Mercier, Martine Duclos, Luc Léger and François Carré conducted the initial analyses and drafted the initial manuscript. Anne Le Cunuder conducted statistical analysis and drafted the initial manuscript. François Carré and Daniel Mercier designed data collection instruments, coordinated and supervised data collection and reviewed the manuscript. All authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work.

543 **Ethics approval**

544 The study was approved by the local ethics committee (Centre Hospitalier Universitaire de Rennes, n° 21.115), and all procedures were following the ethical standards of the Helsinki Declaration of 1975 as revised in 2008.

547 **Consent to participate**

548 Written, informed consent was obtained from the adolescents and the parents.

549 **Consent for publication**

550 NA

551
<table><caption>**Table 1.** Subjects characteristics studied according to the sex</caption><thead><tr><th></th><th>Overall</th><th>Boys</th><th>Girls</th><th>P*</th></tr></thead><tbody><tr><td>N</td><td>8084</td><td>4126</td><td>3958</td><td></td></tr><tr><td>Age</td><td>11.2 ± 0.4</td><td>11.3 ± 0.4</td><td>11.2 ± 0.4</td><td>0.36</td></tr><tr><td>10-10.9 years</td><td>1611 (19.9)</td><td>796 (19.3)</td><td>815 (20.7)</td><td></td></tr><tr><td>11-11.9 years</td><td>6062 (75.0)</td><td>3108 (75.3)</td><td>2954 (74.6)</td><td></td></tr><tr><td>12-12.9 years</td><td>349 (4.3)</td><td>193 (4.7)</td><td>156 (3.9)</td><td></td></tr><tr><td>13-13.9 years</td><td>62 (0.8)</td><td>29 (0.7)</td><td>33 (0.8)</td><td></td></tr><tr><td>Sport participation</td><td></td><td></td><td></td><td></td></tr><tr><td>No</td><td>3287 (45.0)</td><td>1594 (42.8)</td><td>1693 (47.2)</td><td></td></tr><tr><td>Outdoor (club)</td><td>2583 (35.4)</td><td>1303 (35.0)</td><td>1280 (35.7)</td><td></td></tr><tr><td>School</td><td>455 (6.2)</td><td>231 (6.2)</td><td>224 (6.2)</td><td><strong>&lt;0.001</strong></td></tr><tr><td>Both</td><td>976 (13.4)</td><td>595 (16.0)</td><td>391 (10.9)</td><td></td></tr><tr><td>Weight (kg)</td><td>40.17 ± 10.55</td><td>39.70 ± 9.76</td><td>40.63 ± 11.07</td><td><strong>&lt;0.005</strong></td></tr><tr><td>Height (cm)</td><td>148.22 ± 7.80</td><td>147.67 ± 7.56</td><td>148.89 ± 7.88</td><td><strong>&lt;0.005</strong></td></tr><tr><td>Body mass Index (kg/m²)</td><td>18.11 ± 3.66</td><td>18.08 ± 3.51</td><td>18.14 ± 3.80</td><td>0.42</td></tr><tr><td>20-m shuttle run test - Prefit (stages)</td><td>7.08 ± 2.66</td><td>7.70 ± 2.82</td><td>6.44 ± 2.34</td><td><strong>&lt;0.005</strong></td></tr><tr><td>20-m shuttle run test - Prefit (speed, km.h<sup>-1</sup>)</td><td>9.46 ± 1.38</td><td>9.82 ± 1.49</td><td>9.08 ± 1.21</td><td><strong>&lt;0.005</strong></td></tr><tr><td>20-m shuttle run test - Original (stages)**</td><td>3.0 ± 1.6</td><td>3.2 ± 1.7</td><td>2.5 ± 1.4</td><td><strong>&lt;0.005</strong></td></tr><tr><td>Absolute Handgrip strength (kg)</td><td>20.02 ± 5.10</td><td>20.40 ± 5.00</td><td>19.62 ± 4.93</td><td><strong>&lt;0.005</strong></td></tr></tbody></table>

553 Values are mean ± standard deviation or number (%)

554 * For comparison between boys and girls, a t-test for continuous variables and chi-squared test for categorical

555 variables were used.

556 ** 20-m SRT original stages were estimated with the PREFIT speeds as recommended by Mora-Gonzalez et

557 al. [18]
<table><caption>**Table 2.** Physical fitness according to weight status.</caption><thead><tr><th></th><th>Thin</th><th>Normal</th><th>Overweight</th><th>Obesity</th><th>P*</th></tr></thead><tbody><tr><td><strong>Total</strong></td><td>N = 920</td><td>N = 3586</td><td>N = 770</td><td>N = 273</td><td></td></tr><tr><td>20-m shuttle run test - Prefit (stage)</td><td>7.88 ± 2.52<sup>b,c,d</sup></td><td>7.43 ± 2.55<sup>c,d</sup></td><td>5.48 ± 2.00<sup>d</sup></td><td>4.08 ± 1.80</td><td><strong>&lt;0.005</strong></td></tr><tr><td>Absolute Handgrip strength (kg)</td><td>17.60 ± 4.37<sup>b,c,d</sup></td><td>19.94 ± 4.84<sup>c,d</sup></td><td>21.23 ± 4.67<sup>d</sup></td><td>23.89 ± 5.01</td><td><strong>&lt;0.005</strong></td></tr><tr><td><strong>Girls</strong></td><td><strong>Thin</strong><br>N = 486</td><td><strong>Normal</strong><br>N = 1738</td><td><strong>Overweight</strong><br>N = 378</td><td><strong>Obesity</strong><br>N = 128</td><td></td></tr><tr><td>20-m shuttle run test - Prefit (stage)</td><td>7.22 ± 2.23<sup>b,c,d</sup></td><td>6.67 ± 2.29<sup>c,d</sup></td><td>5.11 ± 1.71<sup>d</sup></td><td>3.98 ± 1.57</td><td><strong>&lt;0.005</strong></td></tr><tr><td>Absolute Handgrip strength (kg)</td><td>17.16 ± 4.12<sup>b,c,d</sup></td><td>19.52 ± 4.84<sup>c,d</sup></td><td>21.04 ± 4.58<sup>d</sup></td><td>23.88 ± 4.84</td><td><strong>&lt;0.005</strong></td></tr><tr><td><strong>Boys</strong></td><td><strong>Thin</strong><br>N = 434</td><td><strong>Normal</strong><br>N = 1848</td><td><strong>Overweight</strong><br>N = 392</td><td><strong>Obesity</strong><br>N = 145</td><td></td></tr><tr><td>20-m shuttle run test - Prefit (stage)</td><td>8.62 ± 2.62<sup>b,c,d</sup></td><td>8.16 ± 2.57<sup>c,d</sup></td><td>5.84 ± 2.20<sup>d</sup></td><td>4.17 ± 1.97</td><td><strong>&lt;0.005</strong></td></tr><tr><td>Absolute Handgrip strength (kg)</td><td>18.13 ± 4.12<sup>b,c,d</sup></td><td>20.34 ± 4.84<sup>c,d</sup></td><td>21.41 ± 4.5<sup>d</sup></td><td>22.69 ± 5.25</td><td><strong>&lt;0.005</strong></td></tr></tbody></table>

Values are mean ± standard deviation

* One-way ANOVA test. Pairwise Post-hoc comparisons were performed using linear contrasts, after applying a Bonferroni correction for multiple comparisons (a = thin; b = normal; c = overweight; d = obesity).
1

<table><caption>**Table 3.** Physical fitness according to organized sport participation (club and school).</caption><thead><tr><th></th><th>No</th><th>School only</th><th>Club only</th><th>Club and school</th><th>P*</th></tr></thead><tbody><tr><td><strong>Total</strong></td><td>N = 3287</td><td>N = 455</td><td>N = 2583</td><td>N = 976</td><td></td></tr><tr><td>20-m shuttle run test - Prefit (stage)</td><td>6.22 ± 2.46<sup>b,c,d</sup></td><td>7.05 ± 2.59<sup>c,d</sup></td><td>7.34 ± 2.55<sup>d</sup></td><td>8.14 ± 2.61</td><td><strong>&lt;0.005</strong></td></tr><tr><td>Absolute Handgrip strength (kg)</td><td>19.95 ± 5.22</td><td>19.92 ± 5.68</td><td>20.05 ± 4.82</td><td>20.19 ± 4.29</td><td>0.60</td></tr><tr><td><strong>Girls</strong></td><td><strong>No</strong></td><td><strong>School only</strong></td><td><strong>Club Only</strong></td><td><strong>Club and school</strong></td><td></td></tr><tr><td></td><td>N = 1693</td><td>N = 224</td><td>N = 1280</td><td>N = 391</td><td></td></tr><tr><td>20-m shuttle run test - Prefit (stage)</td><td>5.86 ± 2.23<sup>b,c,d</sup></td><td>6.47 ± 2.31<sup>c,d</sup></td><td>6.69 ± 2.20<sup>d</sup></td><td>7.40 ± 2.51</td><td><strong>&lt;0.005</strong></td></tr><tr><td>Absolute Handgrip strength (kg)</td><td>19.56 ± 4.89</td><td>19.40 ± 6.09</td><td>19.71 ± 4.93</td><td>19.74 ± 4.38</td><td>0.73</td></tr><tr><td><strong>Boys</strong></td><td><strong>No</strong></td><td><strong>School only</strong></td><td><strong>Club Only</strong></td><td><strong>Club and school</strong></td><td></td></tr><tr><td></td><td>N = 1594</td><td>N = 231</td><td>N = 1303</td><td>N = 595</td><td></td></tr><tr><td>20-m shuttle run test - Prefit (stage)</td><td>6.61 ± 2.81<sup>b,c,d</sup></td><td>7.92 ± 2.80<sup>c,d</sup></td><td>7.59 ± 2.62<sup>d</sup></td><td>8.73 ± 2.53</td><td><strong>&lt;0.005</strong></td></tr><tr><td>Absolute Handgrip strength (kg)</td><td>20.38 ± 5.49</td><td>20.44 ± 5.14</td><td>20.37 ± 4.69</td><td>20.48 ± 4.36</td><td>0.97</td></tr></tbody></table>

2

Values are mean ± standard deviation

3

* One-way ANOVA test. Pairwise Post-hoc comparisons were performed using linear contrasts, after applying a Bonferroni correction for multiple comparisons (a = no; b = school only; c = club only; d = club and school).

4

5
<table><caption>**Table 4.** Centiles estimation for cardiorespiratory fitness (20-m shuttle run test - PREFIT, stages) by sex and age based on 8022 test performances of French adolescents aged 10-12 years.</caption><thead><tr><th rowspan="2"></th><th rowspan="2">Mean ± SD</th><th colspan="11">Percentiles</th></tr><tr><th>5</th><th>10</th><th>20</th><th>30</th><th>40</th><th>50</th><th>60</th><th>70</th><th>80</th><th>90</th><th>95</th></tr></thead><tbody><tr><td><strong>PREFIT protocol</strong></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td><em>Boys</em></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>10-10.9 years</td><td>7.7 ± 2.8</td><td>3.5</td><td>4.0</td><td>5.5</td><td>6.0</td><td>7.0</td><td>8.0</td><td>8.5</td><td>9.5</td><td>10.0</td><td>11.0</td><td>12.0</td></tr><tr><td>11-11.9 years</td><td>7.7 ± 3.2</td><td>3.3</td><td>4.0</td><td>5.0</td><td>6.0</td><td>7.0</td><td>7.5</td><td>8.5</td><td>9.5</td><td>10.5</td><td>11.5</td><td>12.5</td></tr><tr><td>12-12.9 years</td><td>6.5 ± 2.9</td><td>2.5</td><td>3.0</td><td>4.0</td><td>4.5</td><td>5.5</td><td>6.0</td><td>7.0</td><td>7.5</td><td>9.0</td><td>10.5</td><td>12.0</td></tr><tr><td><em>Girls</em></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>10-10.9 years</td><td>6.4 ± 2.4</td><td>3.0</td><td>3.5</td><td>4.5</td><td>5.0</td><td>5.5</td><td>6.0</td><td>7.0</td><td>7.5</td><td>8.5</td><td>9.5</td><td>10.5</td></tr><tr><td>11-11.9 years</td><td>6.4 ± 2.6</td><td>3.0</td><td>3.5</td><td>4.5</td><td>5.0</td><td>5.5</td><td>6.5</td><td>7.0</td><td>7.5</td><td>8.5</td><td>9.5</td><td>10.5</td></tr><tr><td>12-12.9 years</td><td>5.2 ± 2.2</td><td>2.0</td><td>2.7</td><td>3.0</td><td>4.0</td><td>4.5</td><td>5.0</td><td>5.5</td><td>6.0</td><td>7.0</td><td>8.5</td><td>9.5</td></tr></tbody></table>

Centile values were estimated by using GAMLSS model (Box-Cox power exponential distribution) for exact ages. SD indicates standard deviation.

7

8
<table><caption>**Table 5.** Centiles estimation for handgrip strength (absolute values) by sex and age based on 8022 test performances of French children aged 10-12 years.</caption><thead><tr><th rowspan="2"></th><th rowspan="2">Mean ± SD</th><th colspan="10">Percentiles</th></tr><tr><th>5</th><th>10</th><th>20</th><th>30</th><th>40</th><th>50</th><th>60</th><th>70</th><th>80</th><th>90</th><th>95</th></tr></thead><tbody><tr><td colspan="12"><em>Boys</em></td></tr><tr><td>10-10.9 years</td><td>19.33 ± 4.64</td><td>13.38</td><td>14.50</td><td>15.60</td><td>16.80</td><td>17.96</td><td>18.80</td><td>19.80</td><td>20.90</td><td>22.26</td><td>24.50</td><td>26.80</td></tr><tr><td>11-11.9 years</td><td>20.66 ± 4.90</td><td>14.10</td><td>15.40</td><td>16.90</td><td>18.00</td><td>19.10</td><td>20.10</td><td>21.10</td><td>22.40</td><td>23.90</td><td>26.20</td><td>28.34</td></tr><tr><td>12-12.9 years</td><td>22.28 ± 7.32</td><td>12.50</td><td>13.90</td><td>16.60</td><td>18.20</td><td>19.90</td><td>21.00</td><td>22.60</td><td>24.60</td><td>27.50</td><td>30.40</td><td>35.80</td></tr><tr><td colspan="12"><em>Girls</em></td></tr><tr><td>10-10.9 years</td><td>18.65 ± 4.49</td><td>12.90</td><td>14.00</td><td>15.60</td><td>16.51</td><td>17.30</td><td>18.00</td><td>18.70</td><td>19.80</td><td>21.10</td><td>23.70</td><td>26.75</td></tr><tr><td>11-11.9 years</td><td>19.89 ± 4.91</td><td>13.20</td><td>14.60</td><td>16.00</td><td>17.36</td><td>18.40</td><td>19.30</td><td>20.20</td><td>21.40</td><td>23.10</td><td>25.70</td><td>28.20</td></tr><tr><td>12-12.9 years</td><td>21.76 ± 6.85</td><td>12.50</td><td>14.80</td><td>16.52</td><td>18.00</td><td>20.00</td><td>21.50</td><td>22.10</td><td>24.04</td><td>25.86</td><td>28.44</td><td>32.36</td></tr></tbody></table>

Centile values were estimated by using GAMLSS model (Box-Cox power exponential distribution) for exact ages. SD indicates standard deviation.