Exercise Induced Changes in Fat Metabolism
Condition: Healthy Volunteers
Study type: Interventional

Summary: 
      If eligible to participate in the research study after completing the physical screening
      procedures, participants will be asked to return to the Substrate Metabolism Laboratory on
      another occasion after a short fast (no food or beverages - besides water) for at least 6
      hours. After participants arrive, participants will rest quietly for approximately 30 min.
      The investigators will then collect a blood sample from a vein in participants hand, or
      forearm. After obtaining a baseline blood sample, participants will exercise at a moderate
      intensity (on a treadmill or a stationary bike) for one hour. This one hour moderate exercise
      session will feel like a slow jog during which participants would be able to carry a
      conversation. In order for the investigators to measure energy expended and the amount of fat
      participants are burning during exercise, the investigators will periodically ask
      participants to breathe through a mouthpiece so the investigators can collect participants
      expired breath. After the exercise session the investigators will collect another blood
      sample from a vein in participants hand, or forearm.
    

Detailed description: 
      General study design

        -  Subjects who exercise regularly will be instructed to exercise exactly 3 days before the
           experimental trial, and then abstain from their exercise training program until after
           the experiment is complete.

        -  Subjects will arrive to the Substrate Metabolism Laboratory (1210 CCRB) after at least a
           6h fast.

        -  After resting quietly in the laboratory for approximately 30min, Dr. Horowitz will
           collect a resting blood sample by venipuncture, as he has done in our other IRB approved
           protocols (e.g., HUM00029179). Briefly, Dr. Horowitz will wash his hands and put on
           gloves. The participant's skin will be disinfected at the venipuncture site with
           isopropyl alcohol. Single-use needles will be used for each participant and immediately
           discarded into a biohazard sharps container after use. After the blood draw, direct
           pressure will be applied to the site of needle insertion to avoid/reduce bruising and
           discomfort.

        -  Subjects will exercise (bike or treadmill) for 1h at a moderate exercise intensity
           (approximately 65% of their predicted VO2peak). This moderate exercise intensity has
           been used extensively by Dr. Horowitz's laboratory in previous exercise testing and
           training studies in both lean and obese individuals, and is well tolerated by both
           populations.

             -  During the exercise session, subjects will wear a heart rate monitor to ensure
                participants are exercising at the correct exercise intensity.

             -  Subjects will also use the mouthpiece and nose clip (described above) for ~5min at
                the beginning, middle, and end of exercise to verify they are exercising at
                approximately 65% of their predicted VO2peak.

             -  A study team member will be present with the participant at all times during
                exercise to ensure the comfort and safety.

        -  Immediately after exercise another blood sample will be collected.
    

Intervention name(s): Exercise session
Intervention type(s): Other
Intervention description(s): There is no drug or device intervention in this study. Subjects will exercise at a moderate intensity for 60 minutes and a blood sample will be obtained before and after the exercise session
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Basic Science