IRCT20190720044283N4 IRCT 2021-10-27 University of Guilan Caffeine Dose and Autonomic Recovery Effect of caffeine dose on heart rate variability, rate pressure product and some fatigue indexes after endurance exercise in trained men 2021-09-26 anticipated 12 Complete https://irct.ir/trial/59493 interventional Randomization: Randomized, Blinding: Single blinded, Placebo: Used, Assignment: Crossover, Purpose: Other, Randomization description: Use the random selection method by Excel software. In this method, we first enter the names of the subjects in Excel, and then in another part, we specify the position of the desired groups in two separate sections of 6 subjects. Then in these two sections, we will execute the following code so that people are randomly placed in groups of 6 subjects. =INDEX($A$3:$A$12,RANDBETWEEN(1,ROWS($A$3:$A$12)),1), Blinding description: In this study, subjects were not aware of how caffeine or placebo was distributed. The determined amount of supplement and placebo was weighed for each subject separately and was delivered to the subjects by coding by the laboratory operator on each day of the test. N/A Recovery of indicators of the autonomic nervous system. Intervention 1: Intervention group: Dose of 6 mg/kg of caffeine and endurance activity. Intervention 2: Intervention group: Dose of 9 mg/kg of caffeine and endurance activity. Intervention 3: Control group: Taking placebo along with performing endurance activity. Yes - There is a plan to make this available What will be shared: After analyzing the data, only part of the data related to the main outcome will be shared. When: After approval by the journal publishing the study report To whom: Journal publisher of study reports Conditions: By getting permission from the journal publish the study report Where to obtain: Journal publisher of study reports How to obtain: Public and private terms Journal of the study report Comments: