Hiking is a common recreational activity that provides numerous health benefits, such as reduced risk of heart disease, reduced blood pressure, and improved cardiorespiratory fitness. The use of specifically designed trekking poles has become popular among participants seeking to alleviate sore knees and increase balance and stability while walking. This review provides an overview of physiologic and biomechanical responses elicited when trekking poles are used during outdoor activities, such as hiking or Nordic walking, and discusses the clinical implications of the use of trekking poles. Google Scholar, PubMed, and ScienceDirect databases, as well as university library catalogues, were searched for literature published between 1980 and 2019. The keywords used to search the literature were hiking poles, trekking poles, and Nordic walking and their combination with physiological responses, ground reaction forces, joint forces, spatiotemporal parameters, kinematics, electromyography, and/or balance. The related topics included the academic disciplines of biomechanics, sports science, and wilderness medicine. Reference lists of located studies were also reviewed for additional sources. During free, unloaded walking, users should compare the cost and benefit of using poles: Trekking poles decrease lower extremity loading and forces but increase cardiovascular demand. When carrying a large external load, trekking poles may offer benefit by decreasing lower extremity muscle activity and increasing balance and stability.