Acute effects of resistance training at different range of motions on plantar flexion mechanical properties and force

ABSTRACT

The effects obtained from resistance training depend on the exercise range of motion (ROM) performed. We aimed to examine the acute effects of different exercise ROM resistance training on the plantar flexor muscles. Eighteen healthy untrained male adults participated in three conditions: calf raises in 1) partial condition [final (short muscle length) partial ROM], 2) full condition (full ROM), and 3) control condition. The ankle dorsiflexion (DF) ROM, passive torque at DF ROM, passive stiffness of muscle-tendon unit, and maximal voluntary isometric contraction (MVC-ISO) torque were measured before and immediately after the interventions. There were significant increases in DF ROM, passive torque at DF ROM, and a decrease in MVC-ISO, but no significant interaction in passive stiffness. Post hoc test, DF ROM demonstrated moderate magnitude increases in the full condition compared to the partial (p = 0.023, d = 0.74) and control (p = 0.003, d = 0.71) conditions. Passive torque at DF ROM also showed moderate magnitude increases in the full condition compared to the control condition (p = 0.016, d = 0.69). MVC-ISO had a moderate magnitude decrease in the full condition compared to the control condition (p = 0.018, d=−0.53). Resistance training in the full ROM acutely increases joint ROM to a greater extent than final partial ROM, most likely due to stretch tolerance.

KEYWORDS:

• Flexibility
• passive torque
• stretch tolerance
• passive stiffness
• maximal voluntary isometric contraction

Disclosure statement

No potential conflict of interest was reported by the authors.

Author contributions

YM, AK, KW, DB, and MN designed the study. YM, KK, and RY were responsible for the data acquisition, and YM and MN did the analysis; the data interpretation was undertaken by YM, AK, KW, DB, and MN; all authors were involved in drafting and critically revising the manuscript for intellectual content. All authors read and approved the final manuscript.

Research involving human participants

All procedures in the study were in accordance with the ethical standards of the 1964 Declaration of Helsinki and its later amendments. This study was approved by the Ethics Committee of Niigata University of Health and Welfare (#17677).

Additional information

Funding

This work was supported by JSPS KAKENHI with grant number [19K19890] (Masatoshi Nakamura) and the Austrian Science Fund (FWF) project [J4484] (Andreas Konrad).