Muscular Strength and Endurance Alterations in Cancer Patients

Abstract

0703 Current cancer treatments cause physiological toxicities, which lead to a diminished quality of life for cancer patients during and following treatment. These toxicities can manifest as increased fatigue and muscular weakness. Normal and cancer cells require ATP for normal function, and chemotherapy leads to an apoptotic chemical cascade that depletes ATP. ATP is important for muscular contraction to occur, depletion leads to a decrease in the strength and ability of the muscle to contract. Muscle weakness is also caused by increased protein catabolism that leads to a decrement in skeletal muscle mass. Aerobic exercise programs have decreased fatigue, but little research has focused on muscular strength and endurance. PURPOSE: The purpose of this investigation was to determine the effects of an individualized six-month muscular strength and endurance exercise intervention on cancer patients. METHODS: One hundred-ten cancer patients were used for this investigation. Subjects were classified as exercise (n = 82) or non-exercise (n = 28) based on participation in the exercise program. Muscular strength was assessed with a hand-held dynamometer. Muscular endurance was assessed by the number of repetitions performed on various weight machines (bench press, shoulder press, leg press, lat pull-down, leg curl, and leg extension). Additionally, muscular endurance was measured by the number of crunches that could be performed per minute. After the six-month intervention, exercise and non-exercise subjects were reassessed in the same manner as the initial assessment. RESULTS: Repeated Measures ANOVA was used to determine significant change from pre to post exercise. The exercise group showed significant improvements in upper body (lat pull-down pp = .017, triceps extension pp = .027, shoulder press pp = .043), abdominal (crunches pp = .000), and lower body (leg press pp = .007) muscular endurance following the exercise intervention with no change in muscular strength. The non-exercise group showed no significant changes in upper body (lat pull-down, triceps extension, shoulder press), abdominal (crunches), or lower body endurance (leg press), and had a decrease in muscular strength (handgrip pp = .017). CONCLUSIONS: Muscular strength and endurance can be maintained or improved with exercise training in cancer patients. Suggesting an improved ATP availability and decreased protein catabolism.