Resistance Exercise and Low-Intensity Physical Activity Breaks in Sedentary Time to Improve Muscle and Cardiometabolic Health

Inclusion Criteria

• Are capable and willing to give written informed consent, and understand exclusion criteria
• 65-80 years of age inclusive
• Body Mass Index (BMI) between 18.5-34.9 kg/m2, inclusive
• Physically inactive determined by self-report
• Stable medical therapy for allowable medications for 30 days defined as:
• No addition or removal of a medication
• No change in dosage of a medication
• Having no life-threatening conditions or diseases
• Willing to allow researchers to use data, bio-specimens (blood and muscle tissue), and images (e.g., magnetic resonance imaging) for research purposes after study participation is completed
• At least 2 weeks post-completion of the COVID19 vaccine regimen. a. Acceptable proof of vaccine includes a completed vaccine card and/or letter from a healthcare provider indicating the date that the COVID19 vaccine was completed.

Exclusion Criteria

• Nursing home resident
• Physically Active:

a. > 100 min/wk of moderate OR > 50 min/wk vigorous intensity PA

• Saint Louis University Mental State (SLUMS) score 10% in the last 3 months prior to screening
• History of weight loss surgery.
• Use of medications known to influence study outcomes, such as:
• Insulin
• Oral antidiabetic medications (e.g., metformin)
• Corticosteroids
• Beta-blockers

c. Anticoagulants

• Allergy to lidocaine
• Active smoking
• Current consumption of > 14 alcoholic drinks per week based on self-report
• Regular participation in resistance or aerobic exercise training within 3 months of initial screening
• Absolute Contraindication to Exercise as Defined by the American College of Sports Medicine,16 including:
• Resting diastolic blood pressure > 100 mm Hg
• Resting systolic blood pressure > 180 mm Hg
• Resting heart rate > 100 beats per min
• Having a body weight greater than 440 pounds
• Having medical implants such as a pacemaker or metal joint replacements
• Having tattoos or permanent makeup completed <30 days prior to the visit
• Recent (past 3 months) cancer diagnosis, undergoing immunotherapy, taking immune suppressants
• Presence of allergies or infections requiring antibiotics within the past 14 days
• Recent (past 3 months) major surgery on the abdomen, pelvis, or lower extremities
• Any other condition that in the judgement of the Principal Investigator and/or the Medical Director of this protocol may interfere with study participation and adherence to the protocol.
• Evidence or self-report history of severe depression in the last 5 years.