Circulatory Levels of Irisin in Response to Chronic Resistance Training

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

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

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:

- 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.

- Cardiopulmonary and Strength Fitness Testing. Cardiopulmonary fitness will be
determined via maximum oxygen uptake testing. One maximum repetition (1-RM) will be
used to assess the muscular fitness.

- Spontaneous Physical Activity: Daily activity level for 7 days will be collected.

- 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.

Intervention: The intervention will last 3 weeks with a frequency of 3 training session per
week. We will collect blood samples levels at session 1 (at the beginning of week 1),
session 3 (at the end of week 1), at session 6 (at the end of week 2) and session 9 (at the
end of week 3). Blood draws will occur at the beginning of each session evaluated
(pre-session), at the 45 min mark during each session and immediately after each session
(post-session).

The sessions 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.

During the intervention:

- 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 at sessions 1, 3, 6
and 9.

Irisin will be obtained from blood samples at baseline, during and after training sessions
1, 3, 6 and 9. Irisin will be measured via a commercial enzyme-linked immunosorbent assay.

- 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
days prior to sessions 1, 3, 6 and 9.

Post-Intervention assessments:

- 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.

- Caridorespiratory capacity determined via maximum oxygen uptake testing. One maximum
repetition (1-RM) will be used to assess the muscular fitness.

- Spontaneous Physical Activity: Daily activity level for 7 days will be collected.

Exclusion Criteria:

- Known health problems such as cardiovascular, pulmonary or metabolic disease will be
excluded.

- Pregnant females.

- 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.

- Participants that exercise more than three times per week or strength train more than
twice per week.

- 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