Resistance training immediately after a burn injury has not been investigated previously. This randomised, controlled trial assessed the impact of resistance training on quality of life plus a number of physical, functional and safety outcomes in adults with a burn injury. Patients were randomly assigned to receive, in addition to standard physiotherapy, four weeks of high intensity resistance training (RTG) or sham resistance training (CG) three days per week, commenced within 72 h of the burn injury. Outcome data was collected at six weeks, three and six months after burn injury. Quality of life at 6 months was the primary endpoint. Data analysis was an available cases analysis with no data imputed. Regression analyses were used for all longitudinal outcome data and between-group comparisons were used for descriptive analyses. Forty-eight patients were randomised resistance training (RTG) (n = 23) or control group (CG) (n = 25). The RTG demonstrated improved outcomes for the functional domain of the Burn Specific Health Scale-Brief (p = 0.017) and the Quick Disability of Arm Shoulder and Hand (p < 0.001). Between group differences were seen for C-reactive protein and retinol binding protein (p = 0.001). Total quality of life scores, lower limb disability, muscle strength and volume were not seen to be different between groups (p > 0.05). Resistance training in addition to usual rehabilitation therapy showed evidence of improving functional outcomes, particularly in upper limb burn injuries. Additionally, resistance training commenced acutely after a burn injury was not seen to be harmful to patients.