Response to Letter to Editor “Effects of Intensity, Duration and Muscle Mass on Neuromuscular Fatigue and Blood Pressure After Isometric Handgrip Exercise”

To the Editor,

We sincerely thank the readers for their thoughtful comments regarding our article, “Effects of the Intensity, Duration, and Muscle Mass of Isometric Handgrip Exercise on Neuromuscular Fatigue and Post‐Exercise Blood Pressure Responses: A Crossover Study” [1]. We appreciate their recognition of our efforts to investigate how different isometric handgrip exercise (IHE) protocols influence neuromuscular fatigue and blood pressure responses. Their comments provide an opportunity to further clarify the rationale and scope of our study.

Regarding the first point on the absence of a control group, we agree that randomized controlled trials provide stronger evidence for evaluating the efficacy of an intervention. However, the primary objective of our study was not to determine whether IHE lowers blood pressure compared with no exercise, as this question has been addressed extensively in previous studies. The objective of our study was to compare the physiological effects of different IHE protocols using a repeated‐measures crossover design. In this design, each participant served as his or her own control, thereby minimizing inter‐individual variability and improving the sensitivity for detecting differences among exercise protocols.

With respect to the second comment concerning the evaluation of only acute responses, we agree that long‐term training studies are necessary to determine whether the observed physiological responses can be translated into sustained blood pressure reductions. As stated in the study design, the present study was intentionally designed to investigate acute blood pressure responses because acute physiological adaptations provide mechanistic insight into the factors that may contribute to long‐term training effects [2]. Identifying which exercise protocols most effectively influence neuromuscular fatigue and post‐exercise blood pressure is an important first step before conducting larger longitudinal intervention studies. We agree that future research should evaluate the long‐term effectiveness of these IHE protocols.

We also acknowledge that our participants were healthy young adults, which limits the direct generalizability of our findings to older adults or patients with hypertension. This limitation was recognized in our manuscript. We intentionally selected a healthy population to investigate the physiological mechanisms underlying the relationships between neuromuscular fatigue and blood pressure regulation while minimizing the influence of medications and disease‐related variability. Establishing these mechanisms in healthy individuals provides a scientific foundation for future investigations in individuals with hypertension [3].

Overall, we appreciate the readers' thoughtful comments, which strengthen the need for future studies involving randomized controlled designs, longer intervention periods, and clinically relevant populations. We believe our study complements the existing literature by providing mechanistic evidence regarding how individual components of IHE protocols influence neuromuscular fatigue and post‐exercise blood pressure responses. Once again, we thank the readers for their interest in our work and for contributing to the scientific discussion surrounding IHE and blood pressure regulation.

Author Contributions

Jiawei Wang: writing – original draft; writing – review and editing. Changsi Zhang: writing – original draft; writing – review and editing. Yih‐Kuen Jan: writing – original draft; writing – review and editing.

Data Availability Statement

Data sharing not applicable to this article as no datasets were generated or analysed during the current study.