Metabolic Costs of Daily Activities in Older Adults

The work will evaluate the metabolic costs for daily activities across the lifespan and evaluate the influence of having functional impairments.

The work will evaluate the metabolic costs for daily activities across the lifespan and evaluate the influence of having functional impairments. The project will simultaneously conduct a cross-sectional and a case-control study. The primary aim will investigate cross-sectional association between older age and the energy expenditure of daily activities by recruiting approximately 25 adults in each of 7 age groups (20-30,30-40,40-50,50-60,60-70,70-80,80+) for a total of 180 individuals. A secondary aim will investigate the effect of functional impairments on the energy expenditure of daily activities by conducting a case-control study. An additional 25 older adults with functional impairment will be recruited in each age decade (60-70, 70-80, and 80+ years old) to accomplish this aim. Additional outcomes will evaluate rating of perceived exertion differences in daily activities. A tertiary aim will investigate using accelerometers to predict the metabolic costs of daily activities.

Eligibility Criteria:
Inclusion Criteria:

* Age 20+ years old
* Community dwelling adults without significant health issues
* Willingness to undergo all testing procedures
* Weight stable for at least three months
* Able to understand and speak English

Exclusion Criteria:

* Failure to provide informed consent
* A 10% enrollment limit will be applied to avid exercisers in each age decade. Avid exercises will be defined as doing structured exercise 3 or more days per week (e.g. jogging, sports etc., walkers will be permitted in the study). Based on our experience, avid exercisers volunteer for this type of research at a high rate and thus the investigators will limit these individuals to prevent a biased comparison
* Use of walker (use of a cane is permitted)
* Lower extremity amputation
* Develops chest pain or severe shortness of breath during physical stress
* Post-stroke syndrome causing ambulatory deficits (other stroke survivors permitted)
* Pacemaker
* Needs assistance with basic activities of daily living: feeding, dressing, continence, bathing, toileting, and transferring from a bed to a chair or from a chair to walking
* Lives in a nursing home; persons living in assisted or independent housing are not excluded
* For adults over the age of 60: \>2 errors on the Short, portable mental status questionnaire administered after written informed consent
* Excessive alcohol or substance abuse within six months or consumption of \>14 alcohol drinks/week
* For women who are child-bearing age (up to 62 years of age): pregnant or breast-feeding
* Participation in a structured weight loss program or fad diet in the last month;
* Weight reduction surgery in the past year
* Known neuromuscular disorder (Rhabdomyolysis, Myasthenia Gravis, Ataxia, Apraxia, post-polio syndrome, mitochondrial myopathy, chronic fatigue syndrome etc.)
* Diagnosed neuropathy that causes pain
* Symptomatic peripheral arterial disease
* Unable to communicate because of severe hearing loss or speech disorder
* Severe visual impairment, which would preclude completion of the assessments
* Progressive, degenerative neurologic disease, e.g., Parkinson's Disease, Multiple Sclerosis, Amyotrophic lateral sclerosis
* Severe rheumatologic or orthopedic diseases, e.g., awaiting joint replacement, active inflammatory disease; self-reported severe osteoarthritis
* Terminal illness, as determined by the participant
* Severe pulmonary disease, requiring the use of supplemental oxygen or steroid therapy
* Severe cardiac disease, including New York Heart Association Class III or IV congestive heart failure, clinically significant aortic stenosis, recent history of cardiac arrest, use of a cardiac defibrillator, or uncontrolled angina
* Other significant comorbid disease discovered during medical screening, e.g. renal failure on hemodialysis, psychiatric disorder (e.g. bipolar, schizophrenia); chronic fatigue syndrome etc...
* Liver diseases: chronic hepatitis, an inflammatory disease, or cirrhosis
* Pregnancy. Participants within childbearing age will have a pregnancy test.
* Contraindications to graded exercise testing according to the American Thoracic Society:
* Acute myocardial infarction (\<6 months since event)
* Unstable angina
* Uncontrolled arrhythmias causing symptoms or hemodynamic compromise
* Syncope
* Active endocarditis
* Acute myocarditis or pericarditis
* Symptomatic severe aortic stenosis
* Uncontrolled heart failure
* Acute pulmonary embolus or pulmonary infarction
* Thrombosis of lower extremity
* Suspected dissecting aneurysm
* Uncontrolled asthmas
* Pulmonary edema
* Room air desaturation at rest \< 85%
* Respiratory failure
* Acute non cardiopulmonary disorder that may affect exercise performance