Admission to an Intensive Care Unit (ICU) initiates an interprofessional and interdisciplinary approach to bring the patient back to health with normal or near normal function. Physiotherapists play a vital role in restoring function to the patient. The role of physiotherapy (PT) in the ICU has moved from primarily being one of only respiratory care to one that also encompasses early rehabilitation and exercise training. Early mobilization in the ICU has gained prominence in the recent years and is becoming standard practice across many centers. However, the impact on weaning with these interventions is not known. This review highlights the dysfunctions from an ICU admission and the rationale for instituting early PT in the ICU. In addition, evidence from systematic reviews and meta-analysis is reviewed to determine the impact of PT interventions on weaning. Evidence suggests the benefit of active mobilization and inspiratory muscle training in facilitating weaning. In addition, these interventions along with neuromuscular electrical stimulation further improve physical function and reduce the risk of critical illness polyneuromyopathy. Therefore, early PT does have significant functional benefits to ICU patients. However, more studies are required to determine how various interventions and intensities of exercise training improve weaning outcomes.