Maximal isometric strength indices are associated with the oxygen cost of walking and running in recreationally active men and women

ABSTRACT

This study assessed the associations of maximal isometric strength and movement economy in 126 recreationally active men and women. Oxygen consumption was assessed through a graded treadmill test with 4-minute increments (4–12 km∙h⁻¹). Maximal isometric leg extensor, leg flexor and handgrip strength were assessed by isometric dynamometry. Models of best fit for gross oxygen cost and gross caloric unit cost were observed across the majority of velocities when the leg extensor/flexor strength ratio and handgrip strength were combined (R² = 0.207–0.525 and R² = 0.152–0.475, respectively). Additionally, the oxygen cost differed statistically for the majority of velocities when participants were split by the median of leg extensor strength (12.3–26.3 ml∙kg⁻¹∙km⁻¹, p < 0.05) and the average of all strength variables (13.9–30.3 ml∙kg⁻¹∙km⁻¹, p < 0.05). Our data underline the importance of maintaining maximal strength in order to perform activities with low to moderate oxygen demands.

KEYWORDS:

• Walking economy
• oxygen consumption
• maximal strength
• gross caloric unit cost
• gross oxygen cost

Authors’ contributions

MS, ZC, KW and SC participated in designing the study, contributed to the data collection and data analysis, interpretation of results and drafted the manuscript; XW, SL and TZ contributed to data collection. All authors have read and approved the final version of the manuscript. MS and SC had full access to all data included in this study and take responsibility for the integrity of the data and the accuracy of the data analysis.

Disclosure statement

The authors declare that they have no competing interests. Internal funding was received by Shanghai Jiao Tong University.