Cakir et al. [1] raise an excellent point regarding the mental health of post-operative patients. We too were surprised by the lack of statistically significant difference in mental health scores between the post-operative walking group and the control group. Because our study design focused on the effect of walking on the physical recovery profile, we did not have pre-participation mental health profiles available.

We agree that the similarity in post-operative mental health scores could be a result of the walking group having a lower pre-operative mental health score than the control group, thus making the final scores a significant finding. Another possibility is that the walking intervention’s effect on mental health is greatest in the first few weeks post-operatively. We may have missed this effect in our study of patients who were 30 days status post-surgery. Lastly, our study is limited by a small sample size. We may have lacked the statistical power to elucidate a difference in mental health scores between post-operative patients who walked and those that did not.

We agree that future research should more thoroughly incorporate mental health evaluations in the pre- and post-operative period using a tool such as the Warwick–Edinburgh Mental Well-being Scale (WEMWBS) [2].