Background For patients with diabetic foot ulcers, offloading is one crucial aspect of treatment and aims to redistribute pressure away from the ulcer site. In addition to offloading strategies, patients are often advised to reduce their activity levels. Consequently, patients may avoid exercise altogether. However, it has been suggested that exercise induces an increase in vasodilation and tissue blood flow, which may potentially facilitate ulcer healing. The aim of this systematic review was to determine whether exercise improves healing of diabetic foot ulcers. Review We conducted a systematic search of MEDLINE, CINAHL and EMBASE between July 6, 2009 and July 6, 2019 using the key terms and subject headings diabetes, diabetic foot, physical activity, exercise, resistance training and wound healing. Randomised controlled trials were included in this review. Three randomised controlled trials (139 participants) were included in this systematic review. All studies incorporated a form of non-weight bearing exercise as the intervention over a 12-week period. One study conducted the intervention in a supervised setting, while two studies conducted the intervention in an unsupervised setting. Two studies found greater improvement in percentage wound size reduction in the intervention group compared with the control group, with one of these studies achieving statistically significant findings (p < 0.05). The results of the third study demonstrated statistically significant findings for total wound size reduction (p < 0.05), however results were analysed within each treatment group and not between groups. Conclusion This systematic review found there is insufficient evidence to conclusively support non-weight bearing exercise as an intervention to improve healing of diabetic foot ulcers. Regardless, the results demonstrate some degree of wound size reduction and there were no negative consequences of the intervention for the participants. Given the potential benefits of exercise on patient health and wellbeing, non-weight bearing exercise should be encouraged as part of the management plan for treatment of diabetic foot ulcers. Further research is required to better understand the relationship between exercise and healing of diabetic foot ulcers.