Investigating the Role of Energy Balance Modification on Health Responses in Chronic Lymphocytic Leukaemia

Inclusion Criteria: * Confirmed diagnosis of CLL (including small lymphocytic leukaemia) as per the International Workshop on CLL Guidelines. * Male or female ≥ 18 years of age * Able to walk on a treadmill or cycle on an ergometer * Pass the Physical Activity Readiness Questionnaires (PAR-Q and PAR-Q+) Exclusion Criteria: * Corticosteroid therapy initiated less than 7 days before study entry. Prednisone 10mg or less or equivalent is allowed. Topical or inhaled corticosteroids are permitted. * Secondary malignancy within 3 years of study enrollment requiring intervention except for adequately treated basal, squamous cell carcinoma or non-melanomatous skin cancer, carcinoma in situ of the cervix, superficial bladder cancer not treated with intravesical chemotherapy or BCG within 6 months, localised prostate cancer and PSA stable. * Absolute contraindications to exercise: Recent (\<6 months) acute cardiac event unstable angina, uncontrolled dysrhythmias causing symptoms or hemodynamic compromise, symptomatic aortic stenosis, uncontrolled symptomatic heart failure, acute pulmonary embolus, acute myocarditis or pericarditis, suspected or known dissecting aneurism and acute systemic infection. * Significant orthopaedic limitations, musculoskeletal disease and/or injury. Due to the nature of the study, persons with known joint, muscle or other orthopaedic limitations that restrict physical activity may be excluded. * Type I diabetes mellitus or uncontrolled Type II diabetes mellitus, or chronic obstructive pulmonary disease * Uncontrolled blood pressure (≥180/90) at rest * Known concurrent HIV, Hepatitis B or Hepatitis C * Unable to comply with other study requirements