Perceived physical fatigability improves after an exercise intervention among breast cancer survivors: a randomized clinical trial

Abstract

Among breast cancer populations, exercise interventions resulted in positive but relatively small improvements on fatigue, which may be due to insensitive measures of global fatigue. Perceived fatigability—whole-body tiredness anchored to standardized tasks/activities of a specific intensity and duration—may help to detect effective exercise interventions reducing fatigue in oncology. We examined whether perceived physical fatigability improved after an exercise intervention. This single center randomized clinical trial of 49 breast cancer survivors was conducted from 2015 to 2017, among which 41 participants (22\u2009=\u2009exercise, 19\u2009=\u2009control) completed the trial and reported their perceived physical fatigability at the first (Visit 1) and the last visit (Visit 3) over 6–14 weeks. Perceived physical fatigability was measured using the 10-item, self-administered Pittsburgh Fatigability Scale (PFS) scored 0–50. The mean differences of perceived physical fatigability between Visit 3 and Visit 1 were computed and compared by intervention groups using two sample t test. Among the 41 women in the study (mean age 54.9\u2009±\u20099.8 years; 80% white), sociodemographic, clinical characteristics and baseline fatigue level were similar by intervention groups, except for antiestrogen use. Post-intervention changes (mean ∆\u2009±\u2009SE) of PFS Physical scores were greater in the exercise group (− 4.4\u2009±\u20091.4; − 22.5%) than the control group (0.2\u2009±\u20091.4;\u2009+\u20091.0%) (p\u2009=\u2009.022). The PFS captured a reduction in fatigue after the exercise intervention among breast cancer survivors. These findings aid mounting efforts to reduce fatigue in oncology by introducing a more sensitive instrument to measure perceived physical fatigability to better evaluate patient-reported outcomes in future cancer trials. Clinicaltrials.gov identifier: NCT 02770781