British Journal of Sports Medicine

doi: 10.1136/bjsports-2024-108671pmid: 39837589

ObjectivesTo examine the association between muscle strength and cardiorespiratory fitness (CRF) with all-cause and cancer-specific mortality in patients diagnosed with cancer, and whether these associations are affected by type and/or stage of cancer.MethodA systematic review with meta-analysis was carried out. Five bibliographic databases were searched to August 2023.ResultsForty-two studies were included (n=46 694). Overall, cancer patients with high muscle strength or CRF levels (when dichotomised as high vs low) had a significant reduction in risk of all-cause mortality by 31–46% compared with those with low physical fitness levels. Similarly, a significant 11% reduction was found for change per unit increments in muscle strength. In addition, muscle strength and CRF were associated with an 8–46% reduced risk of all-cause mortality in patients with advanced cancer stages, and a 19–41% reduced risk of all-cause mortality was observed in lung and digestive cancers. Lastly, unit increments in CRF were associated with a significant 18% reduced risk of cancer-specific mortality.ConclusionHigh muscle strength and CRF were significantly associated with a lower risk of all-cause mortality. In addition, increases in CRF were associated with a reduced risk of cancer-specific mortality. These fitness components were especially predictive in patients with advanced cancer stages as well as in lung and digestive cancers. This highlights the importance of assessing fitness measures for predicting mortality in cancer patients. Given these findings, tailored exercise prescriptions to improve muscle strength and CRF in patients with cancer may contribute to reducing cancer-related mortality.

ObjectiveTo evaluate systematic reviews of randomised controlled trials (RCTs) on the effects of exercise on general cognition, memory and executive function across all populations and ages.MethodsSystematic reviews and meta-analyses of RCTs evaluating the effects of exercise on general cognition, memory and executive function were eligible. Data extraction and risk of bias scoring were conducted in duplicate. The A MeaSurement Tool to Assess systematic Reviews (AMSTAR-2) was used to assess the risk of bias. Effect sizes were pooled using random effects models and reported as standardised mean differences (SMD). Subgroup analyses were conducted for participant and intervention characteristics.General cognition, memory and executive function.Data sourcesCINAHL, The Cochrane Library, Embase, MEDLINE via OVID, Emcare, ProQuest Central, ProQuest Nursing and Allied Health Source, PsycINFO, Scopus, Sport Discus and Web of Science.Results133 systematic reviews (2,724 RCTs and 258 279 participants) were included. Exercise significantly improved general cognition (SMD=0.42), memory (SMD=0.26) and executive function (SMD=0.24). Memory and executive function improvements from exercise were greater for children and adolescents than for adults and older adults. Those with attention-deficit/hyperactivity disorder exhibited greater improvement in executive function than other populations. Effects were generally larger for low- and moderate-intensity interventions. Shorter interventions (1–3 months) and exergames (video games that require physical movement) had the largest effects on general cognition and memory. Findings remained statistically significant after excluding reviews rated as low and critically low quality.ConclusionsThese findings provide strong evidence that exercise, even light intensity, benefits general cognition, memory and executive function across all populations, reinforcing exercise as an essential, inclusive recommendation for optimising cognitive health.Trial registration numberPROSPERO ID: CRD42023468991.