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

Although awareness of the detrimental impact that sedentary behavior has on skeletal muscle
and cardiometabolic health has increased over the last 20 years, more than 60% of older
adults remain sedentary for greater than 8 hours per day. Moreover, 80% to 90% of adults 60
years of age or older do not meet the current public health guidelines for aerobic exercise
(AE) or resistance exercise (RE) based physical activity (PA). Collectively, these adverse
health behaviors contribute to the development of multiple chronic medical conditions
commonly afflicting older adults, including type 2 diabetes, cardiovascular disease,
sarco/dynapenia, frailty, and premature mortality. Emerging evidence suggests that breaking
up sedentary time with light intensity PA (LPA) improves muscle and cardiometabolic health.
Recent data also suggest that RE combined with moderate intensity AE effectively improves
muscle and cardiometabolic health in older adults. However, the impact that RE combined with
LPA breaks in sedentary time has on muscle and cardiometabolic health in older adults remains
unknown. The overall objective of this pilot study is to determine the effect of 16 weeks of
RE alone or RE combined with LPA breaks in sedentary time on muscle and cardiometabolic
health.

Inclusion Criteria:

1. Are capable and willing to give written informed consent, and understand exclusion
criteria

2. 65-80 years of age inclusive

3. Body Mass Index (BMI) between 18.5-34.9 kg/m2, inclusive

4. Physically inactive determined by self-report

5. Stable medical therapy for allowable medications for 30 days defined as:

1. No addition or removal of a medication

2. No change in dosage of a medication

6. Having no life-threatening conditions or diseases

7. 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

Exclusion Criteria:

1. Nursing home resident

2. Physically Active:

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

3. Saint Louis University Mental State (SLUMS) score < 21

4. Evidence or self-report history of deep vein thrombosis, pulmonary embolism,
cardiovascular, peripheral vascular, cerebral vascular, pulmonary, or renal disease

5. Evidence or self-report history of type 1 or 2 diabetes mellitus

6. Evidence or self-report history of a bleeding disorder

7. Evidence or self-report history of recurrent vasovagal episodes

8. Evidence or self-report history of severe depression, Schizophrenia, bipolar disease

9. Evidence or self-report history of mobility disability requiring a walker, wheel
chair, or inability to walk across a small room.

10. Evidence or self-report history of orthopedic limitations that would preclude them
from participation in a dynamic exercise program

11. Evidence or self-report history of severe arthritis (either osteoarthritis or
rheumatoid arthritis) that would preclude them from participation in a dynamic
exercise program

12. Evidence or self-report of history untreated thyroid dysfunction.

13. Weight loss of > 10% in the last 3 months prior to screening

14. History of weight loss surgery.

15. Use of medications known to influence study outcomes, such as:

1. Insulin

2. Oral antidiabetic medications (e.g., metformin)

3. Corticosteroids

4. Beta-blockers

c. Anticoagulants

16. Allergy to lidocaine

17. Active smoking

18. Current consumption of > 14 alcoholic drinks per week based on self-report

19. Regular participation in resistance or aerobic exercise training within 3 months of
initial screening

20. Absolute Contraindication to Exercise as Defined by the American College of Sports
Medicine,16 including:

1. Resting diastolic blood pressure > 100 mm Hg

2. Resting systolic blood pressure > 180 mm Hg

3. Resting heart rate > 100 beats per min

21. Having a body weight greater than 440 pounds

22. Having medical implants such as a pacemaker or metal joint replacements

23. Having tattoos or permanent makeup completed <30 days prior to the visit

24. Recent (past 3 months) cancer diagnosis, undergoing immunotherapy, taking immune
suppressants, and presence of allergies or infections requiring antibiotics

25. Recent (past 3 months) major surgery on the abdomen, pelvis, or lower extremities

26. 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