Gymnastik- och idrottshögskolan, GIH

OBJECTIVE: Specific information for whom and when cardiorespiratory fitness (CRF) is associated with depression risk is lacking. We aimed to study the association between adulthood CRF and incident depression, long-term sickness absence, and disability pension due to depression, as well as examine moderation of sex, age, education, and occupation on associations.

METHODS: A large prospective cohort study follows participants over time with Swedish occupational health screenings data. The study includes 330,247 individuals (aged 16-79 years, 46% women) without a depression diagnosis at baseline. CRF was estimated from a submaximal cycle test.

RESULTS: CRF was associated beneficially from low to higher levels with incident depression and long-term sickness absence due to depression. Further, CRF at high levels (≥46 ml/min/kg) was associated with a decreased risk of receiving disability pension due to depression. The associations remained after adjustment for age and sex, but not lifestyle-related factors and co-morbidity. Participants with moderate and high CRF had 16% and 21%, respectively, lower risk for incident depression, and participants with high CRF had 11% lower risk for long-term sickness absence due to depression. Associations between higher CRF and the outcomes were mainly evident in men, younger participants, and individuals with low education.

CONCLUSION: In a large sample of adults without a depression diagnosis at baseline, higher CRF was shown to be beneficially related to the risk of incident depression and, to some extent, long-term sickness absence due to depression. If causal, targeted interventions focusing on increasing CRF in these sub-groups should be prioritized.

INTRODUCTION: High cardiorespiratory fitness (CRF) has been associated with a lower risk of depression, anxiety, and cerebrovascular disease. The aim was to explore CRF changes over-time associated with these outcomes.

METHODS: This large-scale prospective cohort study, using data from Swedish population-wide registries and databases (during 1972-2020), included men (n=131,431), with measures of estimated CRF (estCRF) in late adolescence (maximal cycle test) and adulthood (submaximal cycle test) (mean years between 24.6, SD 8.8). The study explored how change in estCRF was associated with incident depression, anxiety, and cerebrovascular disease using Cox proportional hazards models. Analyses were performed in 2023.

RESULTS: Higher estCRF in late adolescence and adulthood were associated with a lower risk of incident depression, anxiety, and cerebrovascular disease later in life. For all three outcomes, an increase in estCRF (mL/min/kg and z-score) between the two-time points was associated with a lower risk. Further, decreasing from moderate or high estCRF in adolescence to low estCRF in adulthood, compared to staying at a moderate or high level, was associated with a higher risk of depression and anxiety (HR: 1.24 95% CI 1.07-1.45 and 1.25 95% CI 1.06-1.49, respectively). Conversely, increasing from moderate to high estCRF was associated with a lower risk of incident anxiety (HR: 0.84 95% CI 0.71-0.99).

CONCLUSIONS: The findings indicate that there is a longitudinal association between negative change in estCRF and increased risk of depression, anxiety, and cerebrovascular disease later in life. Decreasing levels of estCRF could be a helpful indicator when identifying these disorders at a population level.