Circulatory Levels of Irisin in Response to Acute Resistance Training

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).

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