Objective: To examine the associations of self‐perceived and objectively‐measured physical fitness with psychological well‐being and distress indicators in young pediatric cancer survivors.Materials and Methods: A total of 116 participants (12.1 ± 3.3 years, 56.9% boys) from the iBoneFIT project participated in this cross‐sectional study. Objectively‐measured physical fitness (muscular fitness) was obtained by handgrip strength and standing long jump tests for the upper and lower body, respectively. Self‐perceived physical fitness was obtained by the International Fitness Scale (IFIS). Positive and negative affect were assessed by the positive affect schedule for children (PANAS‐C), happiness by Subjective Happiness Scale (SHS), optimism by Life Orientation Test‐Revised (LOT‐R), self‐esteem by the Rosenberg Self‐Esteem Scale (RSE), anxiety by State–Trait Anxiety Inventory for Children (STAIC‐R), and depression by Children Depression Inventory (CDI). Multiple linear regressions adjusted by key covariates were performed to analyze associations.Results: No associations were found between objectively‐measured muscular fitness and any of the psychological well‐being and distress indicators (p > 0.05). Self‐perceived overall fitness and flexibility were positively associated with positive affect (β ≥ 0.258, p < 0.05). Self‐perceived cardiorespiratory fitness, speed/agility, and flexibility were negatively associated with depression (β ≥ −0.222, p < 0.05). Finally, self‐perceived cardiorespiratory fitness was also negatively associated with anxiety and negative affect (β ≥ −0.264, p < 0.05).Conclusions: Perceived physical fitness, but not objectively physical fitness, seems to be inversely related to psychological distress variables and to less extent positively related to psychological well‐being. The findings from this study highlight the importance of promoting self‐perceived fitness in the pediatric oncology population.

Background/Objectives: This study aims to investigate the association of movement behaviors with irisin, sclerostin, and bone turnover markers in young pediatric cancer survivors. Methods: A total of 116 young pediatric cancer survivors (12.1 ± 3.3 years; 42% female) were recruited. Time spent in movement behaviors over at least seven consecutive 24 h periods was measured by accelerometers (wGT3x-BT accelerometer, ActiGraph). Blood samples were collected at rest and serum was analyzed for irisin, sclerostin, cross-linked telopeptide of type I collagen (CTX), procollagen type I amino-terminal propeptide (P1NP), total osteocalcin (OC), alkaline phosphatase (ALP), 25-hydroxyvitamin D, parathyroid hormone (PTH), calcium, phosphorous, and magnesium. Results: Irisin and sclerostin were not significantly correlated with bone turnover markers. Sedentary time was negatively correlated with the P1NP (r = −0.411, p = 0.027) and total OC (r = −0.479, p = 0.015) Z-scores, whereas moderate-to-vigorous physical activity was positively correlated with the P1NP (r = 0.418, p = 0.024) and total OC (r = 0.478, p = 0.016) Z-scores. Moreover, total physical activity was positively correlated with the total OC Z-score (r = 0.448, p = 0.025). Finally, the uncoupling index [CTX/P1NP] was positively correlated with sedentary time (r = 0.424, p = 0.012) and negatively correlated with light physical activity (r = −0.352, 0.041). Conclusions: Reducing sedentary time and increasing physical activity may favor bone formation over resorption in young pediatric cancer survivors.

Background/Objectives: This study aims to evaluate the health-related quality of life (HRQoL) of children and adolescent cancer survivors in relation to previously published normative values for typically developing children and adolescents, as well as to analyze the differences in HRQoL based on their levels of physical activity and fitness. Methods: Cross-sectional study with 116 cancer survivors (12.1 ± 3.3 years, 57.8% boys) from two pediatric oncology units in Andalusia (Spain). HRQoL was assessed using PedsQL 4.0 Generic Core Scales. Physical activity was measured with accelerometers, and fitness was evaluated using self-reported and objective tests for muscular fitness. Independent samples t-tests to compare HRQoL between our sample and the normative values published for typically developing children and adolescents of the same age and analysis of covariance (ANCOVA) were conducted to assess differences in HRQoL according to physical activity and fitness categories in our sample. Results: Children and adolescent cancer survivors had lower HRQoL scores compared to typically developing children’s and adolescents’ normative values, except for social functioning. Higher levels of moderate-to-vigorous physical activity were associated with better total, physical, and psychosocial HRQoL scores. Children and adolescent cancer survivors with better levels of cardiorespiratory fitness, motor fitness, and flexibility reported better HRQoL scores in total and psychosocial domains. However, muscular fitness (self-reported and objectively measured) did not show a significant difference in HRQoL. Conclusions: Children and adolescent cancer survivors experience lower HRQoL than their typically developing counterparts. Engaging in at least 30 min of moderate-to-vigorous physical activity per day is associated with fewer HRQoL impairments. Improved fitness, particularly cardiorespiratory fitness, motor fitness, and flexibility, are associated with better HRQoL outcomes. These findings highlight the association between physical activity, fitness levels, and HRQoL in children and adolescent cancer survivors, suggesting the potential benefits of promoting physical activity and enhancing fitness levels.

Purpose: We aimed to analyze the intra-set reliability of 5 sit-to-stand (5-STS) exercises with a functional electromechanical dynamometer (FEMD) and to determine and compare the load-velocity (L-V) profile in the STS exercise in adult pediatric cancer survivors by sex, age, body mass index, and type and treatment of cancer. Method: A total of 47 participants performed the 5-STS test with 5% and 20% body weight (BW) to assess intrasession reliability and analyze differences in L-V profiles by sex, age, BMI, and type and treatment of cancer. Results: Very high and extremely high relative reliability was found for both the 5% STS (ICC = 0.80–0.94) and the 20% STS (ICC = 0.87–0.95) relate to average and peak force, power, and velocity. Regarding L-V profiles, significant differences were only found in relation to sex for the velocity-axis intercept and area under the line (p < 0.05). Conclusion: The 5-STS test with a load of 5% and 20% of BW using a FEMD is a reliable method for assessing strength, power, and velocity exercise in adult pediatric cancer survivors. There was a relation to sex for the variables of L-V profile. Implications for cancer survivors: Reliable assessments of muscular strength, like the 5-STS test using FEMD, offer a safer, less demanding alternative to maximal strength tests (e.g., 1RM), enabling precise intensity control and better-tailored rehabilitation programs.

Objective To synthesise the evidence on the effects of exercise interventions in children and adolescents during and beyond cancer treatment, and to evaluate the methodological quality and certainty of this evidence. Design Umbrella review of systematic reviews with meta-analyses. Data source PubMed, Web of Science, Scopus, SPORTDiscus and CINAHL were searched from inception to January 2026. Eligibility criteria for selecting studies Systematic reviews with meta-analysis of controlled trials (randomised or non-randomised) evaluating exercise interventions in children and adolescents (≤19 years) during and beyond cancer treatment. Reviews without quantitative synthesis, those including only observational studies, or interventions where the isolated effect of exercise could not be determined were excluded. Results 19 systematic reviews with meta-analyses, including 53 primary studies (n=2361 participants), were identified, yielding 80 effect estimates. Attending to the most comprehensive meta-analyses, exercise induced significant benefits on cardiorespiratory fitness (mean difference (MD) 6.92% (95% CI 1.01% to 12.82%)), cognitive function (standardised mean difference (SMD) 0.26 (95% CI 0.08 to 0.44)) and cognitive performance (SMD 0.41 (95% CI 0.17 to 0.65)), with moderate certainty of evidence. Exercise also induced significant benefits on muscle strength (SMD 0.81 (95% CI 0.05 to 1.57)), functional mobility (MD −1.17 s (95% CI −1.86 to −0.49)) and cancer-related fatigue (SMD −0.62 (95% CI −1.21 to −0.03)), although the certainty was low or very low. These effects were observed across meta-analyses focused exclusively on studies conducted during treatment (n=26), after treatment (n=3) or both (n=51). In contrast, no significant effects of exercise were observed for depression, bone mineral density, health-related quality of life, anthropometry or other clinical outcomes (such as mortality, relapse risk and withdrawal rates). Conclusion Exercise appears to be a beneficial intervention in childhood cancer for improving some physical, cognitive and psychosocial outcomes. However, more high-quality research is warranted to strengthen clinical recommendations and inform personalised exercise prescriptions, given that the certainty of evidence remains variable and overall low across outcomes. PROSPERO registration number CRD420251031412.