Circulatory Levels of Irisin in Response to Acute Resistance Training

Study the circulatory levels of irisin in response to one session of high-intensity resistance training in a group of healthy subjects.

Objective: The purpose of this study is to study the circulating levels of irisin in response to acute high-intensity resistance training in a group of healthy young adults.

Sample: The sample will be comprised of adult men and women unpaid volunteers between the ages of 18 and 30. We will recruit 44 participants.

Pre- screening assessments: Informed consent, PAR-Q, Medical History and Exercise History will be used to determine health status and prior exercise experience. Menstrual cycle log will be required for female participants.

Pre-Intervention assessments (baseline):

* Anthropometric measurements and Body Composition: Height, triceps, thigh and calf skinfolds, biceps, thigh, hip, waist, and calf circumferences will be measured. Dual-energy x-ray absorptiometry (DEXA) will be performed to obtain body composition.
* Blood-related variables. Baseline glucose, lactate and hematocrit will be obtained from all participants prior to intervention. Lactate and Hematocrit will be obtained pre-intervention and post-intervention, and within 1 min post workout.

Irisin will be obtained from blood samples at baseline, during and after the training session. Irisin will be measured via a commercial enzyme-linked immunosorbent assay.

* Cardiopulmonary and Strength Fitness Testing. Cardiopulmonary fitness will be determined via maximum oxygen consumption testing. One maximum repetition (1-RM) will be used to assess the muscular fitness.
* Dietary Controls. Each participant will complete the Food Preference Questionnaire. In addition, the Automated Self-Administered 24-hour Recall (ASA24) will be collected for the day prior to the session.
* Familiarization. Participant will be instructed on the muscle conditioning techniques used for strength training so that the techniques can be mastered. The rate of perceived exertion (RPE) scale will also be used for familiarization during these sessions.
* Spontaneous Physical Activity: Daily activity level for 7 days will be collected.

Intervention: Resistance training will consist on a circuit training of 3 sets of 7 exercises focused on major muscle groups. Ten repetitions on each circuit at 70% of the maximum capacity will be performed. Acute intervention will consist of one session. Blood will be collected pre-session, at 45 min during the session, and immediately after the acute intervention exposure (post-session).

Eligibility Criteria:
Inclusion Criteria:

* Participants between 18 and 30 years old
* Males and Females
* Healthy

Exclusion Criteria:

* Participants with known health problems such as cardiovascular, pulmonary or metabolic disease will be excluded.
* Pregnant females will be excluded from the study.
* Any adults found taking medications that affect endocrine or cardiovascular function will also be excluded from the study.
* Individuals found to be less than 110 pounds will also be excluded due to the collection of blood during this study.
* Participants that exercise more than three times per week or strength train more than twice per week will be excluded.
* Individuals that have poor venous access or have expressed a fear of needles or having blood taken will also be excluded.
* Cigarette smoking (current or those who quit within the previous 6 months
* Hypertension
* Overweight and obese
* Pre-diabetics