Zou D, et al. - In subjects participating in the Swedish CArdioPulmonary bioImaging Study (SCAPIS) pilot cohort (n = 603, men 47.9%), aged 50 to 64 years, researchers evaluated the independent association between insomnia and cardiorespiratory fitness (CRF), a well-established risk factor for cardiovascular disease. Participants underwent a submaximal cycle ergometer test for estimation of maximal oxygen consumption (VO₂max). Data on physical activity and sedentary time were also analyzed and insomnia was defined using an insomnia severity index score ≥ 10. The 31.8% of participants had insomnia. Findings demonstrated a modest, but significant, link between insomnia and lower CRF in middle-aged men, but not in women. As observed, insomnia could be associated to cardiovascular disease via reduced CRF.