Effect of Low vs Moderate-intensity Endurance Exercise on Physical Functioning Among Breast Cancer Survivors

Will be used to assess physical function in cancer survivors. It has been validated to assess exercise tolerance (American Thoracic Society, 2002) and has been recommended as a test suitable for fitness, as it is highly correlated with oxygen uptake. An increase in walking distance indicates an improvement in performance. Data will be collected on distance walked (meters), number of rests, and duration of rest during the 6 minutes. Rating of perceived exertion will be monitored. Heart rate and oxygen saturation will be examined using a pulse oximeter.

Patient-Reported Outcomes Measurement Information System (PROMIS) Item Bank v.1.0/1.1 General Health. The Spanish version (Salud general) will be used. It contains two subdomains: Global Physical Health and Global Mental Health. The final score can be converted to a score for the EUROQoL.

PROMIS Item Bank v. 1.2 Physical Function. The Spanish version (Capacidad de Funcionamiento Físico - Cuestionario Abreviado 20) will be used. It consists of 20 items, measuring upper extremity function, as well as gross motor function such as walking and stairs use.

Inventario -II de depresión de Beck (BDI-II). The Spanish version has proper psychometric properties for assessment of depression (internal consistency, obtaining a Cronbach alfa of 0.89 and has reported known-group validity; Vega-Dienstmaier, 2014).

Body Appreciation Scale-2 (BAS-2; Tylka & Wood-Barcalow, 2014), Spanish version will be used to measure body appreciation, an aspect that encompasses positive self-evaluation of body image. It has 13 items with responses ranging from 1 (never) to 5 (always). The Spanish BAS showed adequate internal consistency (Cronbach's α = .91) and construct validity (correlations with BMI, influence of the body shape model, perceived stress, coping strategies, self-esteem and variables from the Eating Disorders Inventory-2). Test-retest reliability ranged from .88 to .90.

Accelerometers will be used to evaluate the amount of time spent in low to moderate and moderate to vigorous physical activity. Accelerometry has been found to be a valid measure of physical activity, as compared to oxygen uptake and calorimetry (Hendelman et al., 2000; Kuffel, et al., 2011) and has been used nationally by the National Health and Nutritional Examination Survey (NHANES) study to document, more precisely than self-reported measures, the intensity and time of physical activity (Hawkins et al., 2009). The procedures established by NHANES (CDC, 2005) will be followed.

International Physical Activity Questionnaire (IPAQ, 2002, self-administered, long Spanish version). The IPAQ assesses multiple domains of activity such as leisure, occupation, household, and transport, among others (Craig et al., 2003). This questionnaire has proved to be reliable (Roman-Viñas et al., 2010), and has been validated with accelerometer, pedometer, physical activity log, and maximal oxygen uptake (van Poppel et al., 2010).

Exercise logs. Participants will be asked to record week number and type and duration of exercise. Logs will be collected at the 6-month evaluation session.