Differences in time to task failure and fatigability between children and young adults
A systematic review and meta-analysis
Keywords:Fatigability, Time to task failure, children, adolescents, adults
Background. The transition from childhood to adulthood is characterized by many physiological processes which can impact physical exercise performance. Performance fatigability (i.e. decline in an objective measure of performance during and/or after exercise) and time to task failure (i.e. capacity for a participant to perform an exercise over an extended period of time until failure; TTF) are commonly used to capture exercise performance.
Objective. To determine the differences in fatigability and TTF between youth (including both children and adolescents, < 18 years old) and young adults, and to evaluate the influence of exercise modalities (i.e. exercise duration and type of exercise) on these potential differences.
Methods. Medline, SPORTDiscus and Cochrane Library were searched. The combination of terms related to the intervention (e.g. whole-body or isometric exercise), population (e.g. child, adolescent) and outcomes (e.g. fatigability, TTF) were used. This meta-analysis was registered on PROSPERO (CRD42020184549).
Results. Thirty-four studies were included. The meta-analyses revealed that both children (SMD –1.15; 95% CI –1.64 to –0.66; p < 0.001) and adolescents (SMD –1.26; 95% CI –2.34 to –0.18; p = 0.022) were less fatigable than adults. A subgroup meta-analysis revealed that children were less fatigable than adults during dynamic exercises (SMD –1.58; 95% CI –2.08 to –1.08; p < 0.001) with no differences during isometric ones (SMD –0.46; 95% CI –1.19 to 0.27; p = 0.22). While children had longer TTF than adults (SMD 0.89; 95% CI 0.15 to 1.63; p = 0.018), it was not the case for adolescents (SMD 0.75; 95% CI –0.12 to 1.62; p = 0.090). Subgroup meta-analyses revealed i) that children had longer TTF than adults for isometric (SMD 1.25; 95% CI 0.60 to 1.90; p < 0.001) but not dynamic exercises (SMD –0.27; 95% CI –2.82 to 2.28; p = 0.83), and ii) that TTF differences between children and adults were larger for short- (SMD 1.46; 95% CI 0.16 to 2.76; p = 0.028) than long-duration exercises (SMD 0.20; 95% CI –0.66 to 1.07; p = 0.64).
Conclusion. Children have higher endurance and are less fatigable than adults. These differences are influenced by the exercise modality, suggesting distinct physiological functioning during exercise between children and adults. The low number of studies comparing these outcomes between adolescents and adults prevents robust conclusions and warrants further investigations in this specific population.
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