The number of patients surviving cancer increases. Survivors of cancer often face adverse effects from their treatment, like fatigue and a higher risk of cardiovascular disease. Exercise leads to a better physical fitness and a decrease in cardiovascular diseases and cancer mortality. In this thesis, predictors of adherence to exercise interventions in patients with cancer were investigated. To improve motivation and adherence to exercise interventions, potential pre-existent barriers to participate in these interventions, like limited knowledge or experience of exercise, should be identified and discussed before starting the cancer treatment. This might help to motivate patients with cancer to participate in an exercise intervention during...