Background: Prior to treatment, breast cancer patients are less physically fit compared to peers; during cancer treatment, their fitness typically declines. Depressive symptoms are associated with reduced activity up to 5 years post-treatment, but research has not identified mechanisms linking depression and lower activity. The current study assessed relationships among breast cancer patients' depression and perceived exertion during exercise as well as heart rate, an objective indicator of exertion.
Methods: Participants were 106 breast cancer patients, stages I-IIIA, who completed surgery but had not started adjuvant treatment. Heart rate and self-rated exertion, measured using the Borg Scale of Perceived Exertion, were assessed every 2 min during a graded exercise test. Depression was assessed using the CES-D and a structured clinical interview.
Results: Compared to women below the CES-D clinical cutoff, women with significant depressive symptoms reported steeper increases in exertion during the exercise test (p = .010) but had similar heart rates (p = .224) compared to women below the cutoff. Major depression history was unrelated to perceived exertion (ps > .224) and heart rate (ps > .200) during exercise.
Conclusions: Women with currently elevated depressive symptoms experienced exercise as more difficult compared to women below the CES-D cutoff, but these self-perceptions did not reflect actual heart rate differences. Depression may make exercise feel more demanding, which could ultimately decrease patients' likelihood of engaging in regular exercise. Results support the use of depression screening tools following breast cancer surgery to identify and intervene on individuals at risk for decreased physical activity during survivorship.
Keywords: Breast cancer; Depression; Depressive symptoms; Exercise; Perceived exertion; Physical activity.