Document Type : Research Paper
Authors
1
Department of Exercise Physiology, University Campous 2, University of Guilan, Rasht, Iran
2
Department of Exercise Physiology, University of Guilan, Rasht, Iran
3
Department of Exercise physiology, University of Guilan, Rasht, Iran
10.22080/jaep.2025.29045.2222
Abstract
Objectives: The sympato-adrenal system is activated in response to various stressors, including exercise, with the degree of activation dependent on both training characteristics and nutritional intake. The present study aimed to determine the acute effects of L-citrulline supplementation on catecholamine and cortisol responses to high-intensity interval resistance training [HIIRT] in trained men.
Methods: This study employed a double-blind, randomized, crossover, placebo-controlled design with nine healthy trained men (age: 21.41 ± 1.13 yr, weight: 79.50 ± 9.35 kg, body fat: 10.67 ± 1.52%). Participants were randomly assigned to two trials, L-citrulline supplementation (12 g) and placebo (12 g maltodextrin), separated by a one-week washout period, combined with an HIIRT protocol (using a 16 kg kettlebell). The protocol consisted of 30:30 sec work/rest intervals with a 1:1 sec eccentric/concentric swing tempo. Blood samples were collected at 3, 10, and 30 minutes post-exercise to measure serum epinephrine, norepinephrine, and cortisol levels. Statistical analysis was performed using repeated-measures ANOVA and Bonferroni post-hoc tests.
Results: Levels of all three hormones (cortisol, epinephrine, and norepinephrine) increased 3 minutes post-exercise compared to baseline in both the supplement and placebo trials. However, only the placebo trial showed a significant decrease by the 30-minute mark compared to baseline (P < 0.05).
Conclusion: Acute L-citrulline supplementation before exercise reduces catecholamine and cortisol levels up to 30 minutes following high-intensity interval resistance training in trained young men.
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