Exercise Training Study Before Bariatric Surgery

The goal of this clinical trial is to figure out if 8 weeks of walking exercise before bariatric surgery improves risk factors for diabetes and other markers of health. This is important as it may help reduce complications after surgery, improve health markers and increase physical activity levels after surgery (which is an important marker of maintaining bariatric weight loss). The main question that this study is trying to answer is whether walking improves a risk factor for type 2 diabetes called insulin sensitivity (how well your body is able to use glucose).

Adults planning to have bariatric surgery will be recruited from the Charlottesville VA area. Before they have their surgery, participants will be randomly assigned (like flipping a coin) to a group that participates in 8 weeks of walking on a treadmill (2-3 times a week) or a group that does their normal care before bariatric surgery.

Researchers will compare the effects of walking before bariatric surgery on:

* Insulin sensitivity (diabetes risk factor)
* Health of blood vessels
* Rate of complications after surgery
* Weight
* Body Fat
* Fitness level

The purpose of the present study is to evaluate the impact of 8 weeks of supervised aerobic exercise prior to bariatric surgery on insulin sensitivity using the hyperinsulinemic-euglycemic clamp. Participants will be recruited from the area surrounding the UVA hospital, while the primary outcome will be insulin sensitivity as measured by the hyperinsulinemic-euglycemic clamp procedure and secondary outcomes include the effects of the exercise intervention on surgical outcomes and cardiometabolic and arterial health in bariatric patients.

Objectives:

Primary Objective: To investigate the effects of exercise + standard care and standard care only in obese individuals prior to bariatric surgery on insulin sensitivity after bariatric surgery.

Secondary Objectives: To examine the effects of exercise + standard care and standard care only in obese individuals prior to bariatric surgery on surgical outcomes, such as length of stay post-surgery, and other clinically relevant outcomes, such as cardiometabolic and arterial health, in adults following bariatric surgery.

Hypotheses:

Primary Hypothesis: An 8-week exercise intervention before bariatric surgery will improve insulin sensitivity as measured by the hyperinsulinemic-euglycemic clamp following bariatric surgery.

Secondary Hypothesis: An 8-week exercise intervention will improve clinically relevant post-surgical outcomes, such as surgical outcomes, quality of life, arterial health, and other cardiometabolic factors following bariatric surgery.

Eligibility Criteria:
Inclusion Criteria:

* BMI: 35 - 45 kg/m2. For adults of Asian race or descent, the BMI cutoff is between 25-27.5 kg/m2 to be considered for surgery and thus will be considered for inclusion in this study.
* Considered sedentary based on self-reported inactivity of \< 2-3 x/week of MVPA within previous 3 months before enrollment.
* Able to walk without use of assistive device, such as cane or walker for ≥ 10 minutes.
* Surgery approved within 6-9 months of initial visit.
* Signed approval from study physician (Dr. Catherine W. Varney; Medical PI of study) that participant is capable to participate.
* Willingness to accept group randomization assignment.

Exclusion Criteria:

* Any serious medical conditions, such as cancer; history cardiovascular disease of stroke, heart attack, or heart failure; type 1 diabetes mellitus; severe psychiatric illness (such as severe depression); kidney disease.
* Autoimmune diseases such as lupus, multiple sclerosis, Graves' disease, or rheumatoid arthritis.
* HIV or tuberculosis.
* Currently taking medications that lead to significant weight loss (e.g., semaglutide; tirzepatide, etc).
* Resting SBP \> 150 mmHg, DBP \> 100 mmHg.
* Current pregnancy or plans to become pregnant during intervention.
* Plans to be away from the Charlottesville, VA area for \> 1 week during intervention or plans of relocating during the intervention.
* Any medical or health condition (e.g., musculoskeletal, orthopedic, or neurological conditions) that is contraindicated for safe exercise testing and training.
* Previous weight-loss surgeries or revisions