In a prospective longitudinal study 35 women were followed during 12 weeks chemotherapy. Measures of body composition were taken using bioelectrical impedance, muscle strength was quantified using a hand-held dynamometer and exercise was measured by the Leisure Time Exercise questionnaire at baseline, 4, 8, 12 weeks of chemotherapy. Patterns of body composition variables, muscle strength and exercise were examined over time.

Mean weight at baseline was 178 lbs. (SD = 47; range=111-309), mean BMI 29.3 (SD 7.8; range=19.4-49.2) and mean LBM 28.8 (SD 4.5; range 23-41). Participants lost an average of 9 lbs. and BMI declined to 28, but LBM remained unchanged. Baseline mean upper extremity muscle strength was 41.8 kg. declining to 36.7 kg. Mean lower extremity muscle strength was 79 kg. at baseline, declining to 70.1 kg. following the first cycle of chemotherapy. Eighteen participants (48.6 %) reported no exercise at all prior to receiving chemotherapy. Seventeen subjects (45.9 %) reported engaging in mild exercise 3 times weekly (SD = 2.3; range = 0 – 7). The frequency and duration of exercise decreased over time.

Women were overweight and inactive prior to the start of chemotherapy. Despite weight loss, BMI remained above recommended levels, predisposing women to obesity-related illnesses. Exercise and physical activity are far below recommended amounts. Declining muscle strength can impact physical functioning. Given the accelerating decline in weight, muscle strength and exercise over time consideration must be give to designing interventions to alleviate these toxic effects.