Cardiorespiratory fitness has declined among French children since 1999, although the decline appears to be getting smaller

Jérémy Vanhelst (1, 2) , Justin Lang (3, 4, 5) , David Matelot (6) , François Carré (7, 8) , Daniel Mercier , Zékya Ulmer (9) , Jean‐michel Oppert (10, 1) , Georges Baquet (11) , Serge Berthoin (12, 11) , Alicia Fillon (13, 14) , Laurent Béghin (15) , Grant Tomkinson (5)

1 CRESS (U1153 / UMR_A 1125) - Centre for Research in Epidemiology and Statistics | Centre de Recherche Épidémiologie et Statistiques
2 UREN - Unité de Recherche en Epidémiologie Nutritionnelle
3 PHAC - Public Health Agency of Canada
4 University of Ottawa [Ottawa]
5 University of South Australia [Adelaide]
6 UBS Lorient - Université de Bretagne Sud - Lorient
7 LTSI - Laboratoire Traitement du Signal et de l'Image
8 Centre Hospitalier Universitaire de Rennes [CHU Rennes] = Rennes University Hospital [Ponchaillou]
9 Caisse Nationale de la Solidarité pour l'Autonomie
10 CHU Pitié-Salpêtrière [AP-HP]
11 URePSSS - Unité de Recherche Pluridisciplinaire Sport, Santé, Société (URePSSS) - ULR 7369 - ULR 4488
12 Université de Lille
13 AME2P - Laboratoire des Adaptations Métaboliques à l'Exercice en Conditions Physiologiques et Pathologiques
14 ONAPS - Observatoire national de l’activité physique et de la sédentarité
15 INFINITE (Ex-Liric) - Institute for Translational Research in Inflammation - U 1286

Background: Cardiorespiratory fitness (CRF) is a strong marker of current and future health. The aim of this study was to assess the national temporal trends in CRF for French children and adolescents between 1999 and 2022. Methods: CRF data were obtained from several cross-sectional studies on 15 420 (51.1% boys) French children and adolescents aged 9-16 years between 1999 and 2022. The 20-m shuttle run test (20mSRT) estimated CRF. Body mass index (BMI) was calculated from measured height and body mass, with BMI z-scores (BMIz) calculated using WHO growth curves. The 20mSRT results were corrected for protocol and converted to z-scores (20mSRTz) using international sex- and age-specific norms. With additional adjustment for BMIz, temporal trends in mean 20mSRT performance (20mSRTz) were estimated using linear regression, with the distance max (Dmax) method used to locate a breakpoint and linear segments fitted to points below and above the breakpoint. Trends in distributional characteristics were assessed visually and described as the ratio of the coefficients of variation (CVs). Results: After adjustment for protocol, age, sex, and BMIz, a large decline in mean 20mSRT performance (trend per decade (95% CI): -1.42 SDs (-1.45, -1.39) or -18.4% (95% CI: -18.8, -18.0)) between 1999 and 2022 was found. Dmax located a breakpoint for the two-linear-segment model in year 2010. There was a large decline in mean 20mSRT performance pre-2010 (trend per decade (95% CI): -2.31 SDs (-2.39, -2.24)), which reduced 0.06-fold to a negligible decline post-2010 (trend per decade (95% CI): -0.15 SD (-0.20, -0.10)). We also found that the trend in mean 20mSRT performance was not uniform across the population distribution. Between 1999 and 2022, there was a small trend in distributional asymmetry, with slightly smaller declines experienced by the high performers (above the 75th percentile). Conclusions: Our data suggest a large decline in the 20mSRT performance of French children and adolescents since 1999. This declining trend seems to have diminished considerably since 2010. Such declines in CRF could translate into declines in health status. Although a slowing in the declining trend in CRF in recent years is encouraging, more data are needed to confirm these findings.

Mots clés: Aerobic fitness; 20-m shuttle run test; youth; trends

Domaines: Sciences du Vivant [q-bio]

Jérémy Vanhelst, Justin Lang, David Matelot, François Carré, Daniel Mercier, et al.. Cardiorespiratory fitness has declined among French children since 1999, although the decline appears to be getting smaller. Scandinavian Journal of Medicine and Science in Sports, 2024, 34 (5), pp.e14641. ⟨10.1111/sms.14641⟩. ⟨hal-04568076⟩