Effects of different intensities of physical exercise on mood and biochemical markers of individuals with depressive disorder

INTERVENTION: This is a randomized crossover study. 50 volunteers of both genders aged 20‐45 years will be recruited and divided into two groups: a) Control Group (n=25) ‐ Composed of healthy individuals, and b) Depressive Disorder Group (n=25) ‐ Composed of volunteers diagnosed with depressive disorder and classified by the Montgomery‐Asberg Depression Scale after evaluation with a psychiatrist. Initially, the volunteers will undergo a medical evaluation and, if fit to practice exercises, will be submitted to a test of progressive velocity carried out until the maximum volitional exhaustion, with increments of 1km every 3 minutes, with an initial load for heating set at 4km/h to obtaining the peak velocity (Vpeak) and the intensities of interest. After three to seven days of the progressive velocity test, the volunteers will be randomly divided to start the protocol by one of the two experimental conditions, and two to seven days later, the second condition will be performed: a) Aerobic exercise performed at 60% of the Vpeak (moderate intensity) for 30 minutes; b) Aerobic exercise performed at 85% of Vpeak (vigorous intensity) until maximum voluntary exhaustion. At baseline, immediately after and 30 minutes after the end of the exercise, the volunteers will answer mood questionnaires (Brunel Mood Scale, Subjective Exercise Experience Scale, State Anxiety Inventory, Visual Analogue Mood Scale) and will have a blood sample collected (12 ml) to evaluate the markers (kynurenine, tryptophan, serotonin, kynurenic acid, quinolinic acid, cortisol, neopterin and clustrin). They will have their heart rate monitored during all tests on the treadmill, along with the Borg Perceived Exertion Scale and the Exercise Pleasure and Displeasure Scale. Maximum volitional exhaustion will be considered as CONDITION: Depressive disorder F03.600 PRIMARY OUTCOME: Expected outcome 1: It is expected to find improvements in mood states after moderate and vigorous intensity exercises and kynurenine pathway metabolites, verified by Brunel Mood Scale, State Anxiety Inventory, Visual Analog Mood Scale and Subjective Scale of Exercise Experience and blood analyzes of kynurenine pathway metabolites, through questionnaire scores and increase in kynurenine metabolites, based on verification of at least 5% variation in measurements, immediately after and 30 minutes after the end of the exercise SECONDARY OUTCOME: Secondary endpoints are not expected INCLUSION CRITERIA: Both genders. Age between 20 and 45 years. With a minimum schooling time of 8 years. affected or not by depressive disorder, the latter with a diagnosis of at least 3 months. Considered minimally active. Considered in good health after medical evaluation. They must not have undergone surgery in the last 6 months. Must not have any physical, muscle and/or joint problems