Duration of Physical Inactivity and Postprandial Lipid Metabolism

Summary

The purpose of the study is to investigate the effect of different periods of physical inactivity on postprandial lipid metabolism in the morning after exercise by measuring plasma triglyceride levels and fat oxidation (burning). The study is a crossover intervention with all healthy participants performing three trials varying in length of physical inactive (4 hours, 8 hours, and 12 hours). All trials include a physical activity control phase (\>8,500 steps/24hr), a physical inactive phase, a moderate intensity cycling session, and a high-fat tolerance test.

Conditions

• Metabolism

Interventions

BEHAVIORAL

4 hours of physical inactivity

A pedometer will be worn by participants during the whole trial. Steps will be monitored. Participants will be required to reach 8,500 steps per day for the first 2 days. On the third day participants need to take 600 steps hourly for 8 hours from 7 am to 3 pm and another 2,000 steps between 3:40 pm to 4 pm. Participant will then stay inactive from 4 pm to 8 pm and do a cycling for one hour in the lab. During the inactivity period, participants will remain seated and steps are only allowed for food, water, and bathroom use. A 3 day food log will be given to participants to log in their diet. Participant will be asks to mimic the diet between trials. A Fitbit will be worn by participants to record the sleep hours during the trial.

BEHAVIORAL

8 hours of physical inactivity

A pedometer will be worn by participants during the whole trial. Steps will be monitored. Participants will be required to reach 8,500 steps per day for the first 2 days. On the third day participants need to take 600 steps hourly for 4 hours from 7 am to 11 am and then 2,000 steps between 11:40 am to 12 pm. During the inactivity period, participants will remain seated and steps are only allowed for food, water, and bathroom use. Participant will then stay inactive from 12 pm to 8 pm and do a cycling for one hour in the lab. A 3 day food log will be given to participants to log in their diet. Participant will be asks to mimic the diet between trials. A Fitbit will be worn by participants to record the sleep hours during the trial.

BEHAVIORAL

12 hours of physical inactivity

A pedometer will be worn by participants during the whole trial. Steps will be monitored. Participants will be required to reach 8,500 steps per day for the first 2 days. On the third day, participant will take 2,000 steps between 7:40 am to 8 am and then stay inactive from 8 am to 8 pm. During the inactivity period, participants will remain seated and steps are only allowed for food, water, and bathroom use. Right after the inactivity intervention, participant will do a 1-hr cycling in lab. A 3 day food log will be given to participants to log in their diet. Participant will be asks to mimic the diet between trials. A Fitbit will be worn by participants to record the sleep hours during the trial.

Sponsors & Collaborators

• University of Texas at Austin

  lead OTHER

Study Design

Allocation

NA

Purpose

BASIC_SCIENCE

Masking

NONE

Model

CROSSOVER

Eligibility

Min Age

18 Years

Max Age

40 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2024-04-01

Primary Completion

2024-11-01

Completion

2024-11-01

Countries

• United States

Study Locations