Low Oxygen Exposure and Weight Status

Eligibility Criteria

• * Obese (BMI between 30-39.9 kg/m2)
• * Born at altitudes below 2,100 meters (\~7,000 feet)
• * Currently residing in Tallahassee, Florida or surrounding area
• * Completed a full FDA authorized or approved COVID-19 vaccination series at least 14 days before any in-person human research activity.
• * Not taking any medication(s) that interfere with oxygen delivery/transport for 4 weeks prior to and throughout the entire study (e.g., includes sedatives, sleeping aids, tranquilizers and/or any medication that depresses ventilation, diuretics, alpha and beta blockers).
• * Willing to refrain from smoking, vaping, chewing tobacco, and dietary supplement use throughout the entire study.
• * Willing to have a hypoxic tent set-up in their home and spend 8 consecutive hours per night in the tent for 8 weeks
• * Lives with a family member, partner/spouse, or roommate who can hear and respond in the unlikely event that the blood oxygen, air oxygen, or air carbon dioxide monitoring alarm would sound.
• * Living in areas that are more than 1,200 m (\~4,000 feet), or have traveled to areas that are more than 1,200 m for five days or more within the last 2 months
• * Individuals who have not completed a full FDA authorized or approved COVID-19 vaccination series at least 14 days before any in-person human research activity.
• * Cardiovascular abnormalities, gastrointestinal disorders, or any condition that interferes with oxygen delivery/transport (e.g., kidney disease, cardiovascular disease, etc.)
• * Oxygen saturation \< 95% while awake or oxygen saturation dips below 88% for a total of ≥ 10 min overnight in normoxic conditions
• * Evidence of apnea or other sleeping disorders
• * Evidence of prior high-altitude pulmonary edema (HAPE) or high-altitude cerebral edema (HACE) diagnosis
• * Diagnosis or family history of sickle cell anemia/trait
• * Hematocrit \<42% for males, \<36% for females
• * Hemoglobin \<13 g/dL for males, \<12 g/dL for females
• * Blood donation within 8 weeks of beginning the study
• * Present condition of alcoholism, anabolic steroids, or other substance abuse issues
• * Women who are pregnant, lactating, planning to become pregnant, or who have had an irregular menstrual cycle in the past 6 mo.
• * Weight gain or loss \> 10% of body weight during the past 6 months
• * Adults unable to consent