The volunteers performed in random order two experimental sessions separated by 48 hours and being: 1) Control and; 2) Inhalation Essential Oil of Eucalyptus. The experimental sessions were always performed in the morning and in the same time of day for the same volunteer, avoiding possible influences circadian rhythm. The experimental sessions were held at the Exercise Physiology Laboratory at the Federal University of Vale do São Francisco with controlled temperature 25°C. At times the pre session (rest), recovery and during the isometric resistance exercise (post-session) in upper limb by hand grip, blood pressure measurements were taken, heart rate and records of the intervals R-R in the absolute time and frequency domain, and are calculated the rate product pressure values (systolic blood pressure x heart rate). Using a disposable face mask participants inhale for ten minutes 0.25 ml of essential oil of eucalyptus measured through adjustable Pipettor 100/1000μl. Inhalation of the substance occurred immediately after the 20 minute rest period in the session Essential Oil of Eucalyptus. In the control session the volunteers remained in a similar manner, with the installed face mask, however inhaling fresh air. The test for determining the maximal voluntary contraction was held in hand grip device Hydraulic Hand Dynamometer Saehan Model SH5001 ranging from 0-90 kgf of grip and precision of 2 kgf. Before the test was performed familiarization session with two series each of 10 seconds with the minimum load allowed by the equipment, the series being separated by a 2-minute recovery period. The value of the maximum voluntary load was determined by the highest value obtained in three attempts of 10 seconds each, with 2 minutes between each trial and the position of the grip handle has been self selected. The experimental isometric resistance exercise sessions were undertaken after 48 hours of interval maximum voluntary contraction test, and the same equipment previously used for the test. The isometric resistance exercise series were held with volunteers sitting positioned comfortably and with the shoulder adducted, the elbow flexed at 90° and the forearm in neutral position, and the position of the self selected grip handle. The highest value obtained in kgf in maximum voluntary contraction test was used as a reference to calculate the absolute intensity of the exercise, which was corresponding to the relative intensity of 30% of the test. Three sets were performed with duration of 1 minute recovery at the same time in both sessions (Eucalyptus Essential Oil and Control).