Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8650313 | Physiology & Behavior | 2018 | 27 Pages |
Abstract
The purpose of this study was to compare the hormonal responses to one session of high-intensity interval training (HIIT, 4â¯Ãâ¯4â¯min intervals at 85-95% maximum heart rate [HRmax], interspersed with 4â¯min of recovery at 75-85% HRmax), resistance training (RT at 50-70% of one repetition maximum 12-15 repetitions per set with 60s of recovery) or both (HIIT+RT) exercise protocol in a cohort of physical inactivity, overweight adults (age 18-30â¯years old). Randomized, parallel-group clinical trial among fifty-one men (23.6â¯Â±â¯3.5â¯yr; 83.5â¯Â±â¯7.8â¯kg; 28.0â¯Â±â¯1.9â¯kg/m2), physical inactivity (i.e., <150â¯min of moderate-intensity exercise per week for >6â¯months), with abdominal obesity (waist circumference â¥90â¯cm) or body mass index â¥25 and â¤30â¯kg/m2 were randomized to the following 4 groups: high-intensity interval training (HIIT, nâ¯=â¯14), resistance training (RT, nâ¯=â¯12), combined high-intensity interval and resistance training (HIIT+RT, nâ¯=â¯13), or non-exercising control (CON, nâ¯=â¯12). Cortisol, total- and free-testosterone and total-testosterone/cortisol-ratio (T/C) assessments (all in serum) were determined before (pre) and 1-min post-exercise for each protocol session. Decreases in cortisol levels were â57.08 (95%CI, â75.58 to â38.58; Pâ¯=â¯0.001; ɳ2â¯=â¯0.61) andâ¯ââ¯37.65 (95%CI, â54.36 to â20.93; Pâ¯=â¯0.001; ɳ2â¯=â¯0.51) in the HIIT and control group, respectively. Increases in T/C ratio were 0.022 (95%CI, 0.012 to 0.031; Pâ¯=â¯0.001; ɳ2â¯=â¯0.49) and 0.015 (95%CI, 0.004 to 0.025; Pâ¯=â¯0.007; ɳ2â¯=â¯0.29) in the HIIT and control group, respectively. In per-protocol analyses revealed a significant change in cortisol levels [interaction effect F(7.777), ɳ2â¯=â¯0.33] and T/C ratio [interaction effect F(5.298), ɳ2â¯=â¯0.25] between groups over time. Additionally, we showed that in both the intention-to-treat (ITT) and per protocol analyses, HIIT+RT did not change serum cortisol, total or free testosterone. The present data indicate a HIIT reduced cortisol and increased total-testosterone/cortisol-ratio levels significantly in physically inactive adults. Further study is required to determine the biological importance of these changes in hormonal responses in overweight men.
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Authors
Gina P. Velasco-Orjuela, MarÃa A. DomÃnguez-Sanchéz, Enrique Hernández, Jorge E. Correa-Bautista, Héctor R. Triana-Reina, Antonio GarcÃa-Hermoso, Jhonatan C. Peña-Ibagon, Mikel Izquierdo, Eduardo L. Cadore, Anthony C. Hackney,