TY - JOUR

T1 - Sex differences in stretch-induced hypertrophy, maximal strength and flexibility gains

AU - Warneke, Konstantin

AU - Zech, Astrid

AU - Wagner, Carl Maximilian

AU - Konrad, Andreas

AU - Nakamura, Masatoshi

AU - Keiner, Michael

AU - Schoenfeld, Brad J.

AU - Behm, David George

N1 - This study was funded by a grant (Project P32078-B) from the Austrian Science Fund FWF. Publisher Copyright: Copyright © 2023 Warneke, Zech, Wagner, Konrad, Nakamura, Keiner, Schoenfeld and Behm.

PY - 2023/1/4

Y1 - 2023/1/4

N2 - Introduction: If the aim is to increase maximal strength (MSt) and muscle mass, resistance training (RT) is primarily used to achieve these outcomes. However, research indicates that long-duration stretching sessions of up to 2 h per day can also provide sufficient stimuli to induce muscle growth. In RT literature, sex-related differences in adaptations are widely discussed, however, there is a lack of evidence addressing the sex-related effects on MSt and muscle thickness (MTh) of longer duration stretch training. Therefore, this study aimed to investigate the effects of 6 weeks of daily (1 h) unilateral static stretch training of the plantar flexors using a calf-muscle stretching device. Methods: Fifty-five healthy (m = 28, f = 27), active participants joined the study. MSt and range of motion (ROM) were measured with extended and flexed knee joint, and MTh was investigated in the medial and lateral heads of the gastrocnemius. Results: Statistically significant increases in MSt of 6%–15% (p <.001–.049, d = 0.45–1.09), ROM of 6%–21% (p <.001–.037, d = 0.47–1.38) and MTh of 4%–14% (p <.001–.005, d = 0.46–0.72) from pre-to post-test were observed, considering both sexes and both legs. Furthermore, there was a significant higher increase in MSt, MTh and ROM in male participants. In both groups, participants showed more pronounced adaptations in MSt and ROM with an extended knee joint as well as MTh in the medial head of the gastrocnemius (p <.001–.047). Results for relative MSt increases showed a similar result (p <.001–.036, d = 0.48–1.03). Discussion: Results are in accordance with previous studies pointing out significant increases of MSt, MTh and ROM due to long duration static stretch training. Both sexes showed significant increases in listed parameters however, male participants showed superior increases.

AB - Introduction: If the aim is to increase maximal strength (MSt) and muscle mass, resistance training (RT) is primarily used to achieve these outcomes. However, research indicates that long-duration stretching sessions of up to 2 h per day can also provide sufficient stimuli to induce muscle growth. In RT literature, sex-related differences in adaptations are widely discussed, however, there is a lack of evidence addressing the sex-related effects on MSt and muscle thickness (MTh) of longer duration stretch training. Therefore, this study aimed to investigate the effects of 6 weeks of daily (1 h) unilateral static stretch training of the plantar flexors using a calf-muscle stretching device. Methods: Fifty-five healthy (m = 28, f = 27), active participants joined the study. MSt and range of motion (ROM) were measured with extended and flexed knee joint, and MTh was investigated in the medial and lateral heads of the gastrocnemius. Results: Statistically significant increases in MSt of 6%–15% (p <.001–.049, d = 0.45–1.09), ROM of 6%–21% (p <.001–.037, d = 0.47–1.38) and MTh of 4%–14% (p <.001–.005, d = 0.46–0.72) from pre-to post-test were observed, considering both sexes and both legs. Furthermore, there was a significant higher increase in MSt, MTh and ROM in male participants. In both groups, participants showed more pronounced adaptations in MSt and ROM with an extended knee joint as well as MTh in the medial head of the gastrocnemius (p <.001–.047). Results for relative MSt increases showed a similar result (p <.001–.036, d = 0.48–1.03). Discussion: Results are in accordance with previous studies pointing out significant increases of MSt, MTh and ROM due to long duration static stretch training. Both sexes showed significant increases in listed parameters however, male participants showed superior increases.

KW - female

KW - long-duration stretching

KW - male

KW - muscle thickness

KW - range of motion

KW - strength capactiy

KW - Physical education and sports

UR - http://www.scopus.com/inward/record.url?scp=85146444063&partnerID=8YFLogxK

U2 - 10.3389/fphys.2022.1078301

DO - 10.3389/fphys.2022.1078301

M3 - Journal articles

C2 - 36685189

AN - SCOPUS:85146444063

VL - 13

JO - Frontiers in Physiology

JF - Frontiers in Physiology

SN - 1664-042X

M1 - 1078301

ER -