High Altitude and Exogenous Carbohydrate Oxidation

Inclusion Criteria

• Men aged 18 - 39 years
• Born at altitudes less than 2, 100 m (~7,000 feet; Examples include Santa Fe, New Mexico; Laramie, Wyoming; Etc.)
• Physically active based on assessment of physical activity history (2-4 days per week aerobic and/or resistance exercise)
• Have supervisor approval (permanent party military and civilians)
• Willing to refrain from alcohol, smokeless nicotine products and dietary supplement use during study periods
• Refrain from taking any nonsteroidal anti-inflammatory drugs (NSAIDs; e.g. aspirin, Advil®, Aleve®, Naprosyn®, or any aspirin-containing product) for 10 days before and at least 5 days AFTER each muscle biopsy. (*Tylenol® or acetaminophen is ok to use if needed for discomfort)

Exclusion Criteria

• Born at altitudes greater than 2, 100 m (~7,000 feet; Examples include Santa Fe, New Mexico; Laramie, Wyoming; Etc.)
• 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 (Examples include Ft. Huachuca, Arizona; Lima, Peru; Feldberg, Germany, Etc.)
• Musculoskeletal injuries that compromise exercise capability
• Metabolic or cardiovascular abnormalities (determined by resting ECG), gastrointestinal disorders (e.g., kidney disease, diabetes, cardiovascular disease, etc.)
• Medication that affects macronutrient metabolism (i.e., diabetes medications, statins, corticosteroids, etc) and/or the ability to participate in strenuous exercise
• Evidence of apnea or other sleeping disorders
• Prior diagnosis of high altitude pulmonary edema (HAPE) or high altitude cerebral edema (HACE)
• Presence of asthma or respiratory tract infections (< 1 month prior)
• Allergies or intolerance to foods (including but not limited to lactose intolerance/milk allergy), vegetarian practices, or medications (including, but not limited to, lidocaine ) to be utilized in the study
• Smoking or vaping
• History of complications with lidocaine
• Taking medications that interfere with oxygen delivery and transport (Includes sedatives, sleeping aids, tranquilizers and/or any medication that depresses ventilation, diuretics, alpha and beta blockers)
• Evidence of any physical, mental, and/or medical conditions that would make the proposed studies relatively more hazardous as determined by the Office of Medical Support and Oversight
• Present condition of alcoholism, anabolic steroids, or other substance abuse issues
• Anemia (hematocrit <38% and hemoglobin <12.5 g/dL) and Sickle Cell Anemia/Trait
• Abnormal prothrombin time (PT)/ partial thromboplastin time (PTT) test or problems with blood clotting
• Blood donation within 8 weeks of beginning the study