The Effect of Long Duration Exercise on the Diastolic Function of the Heart
Condition: Aging
Study type: Interventional

Summary: 
      The purpose of this study is to determine whether vigorous exercise training 4-5 days/week
      for 2 years in sedentary middle aged men and women (ages 45-64) will improve cardiac and
      vascular compliance to a degree equivalent to life-long exercisers and the sedentary young.
      Sedentary aging is associated with impaired diastolic function, which can lead to heart
      failure. However, if exercise training can be implemented early enough in life while
      cardiovascular plasticity still exists, then functional capacity can be maintained,
      preventing heart failure.
    

Detailed description: 
      Objectives: Chronic physical inactivity contributes to the deaths of nearly 1 in 10
      Americans. In seniors, the single most common life-threatening disease is congestive heart
      failure and for these patients, abnormalities of diastolic function play a critical role in
      the pathophysiology of their disease. The primary investigator's previous research has
      demonstrated that: a) healthy but sedentary aging leads to atrophy and stiffening of the
      heart with reduced myocardial and chamber compliance; b) in contrast, highly competitive
      senior athletes had cardiac compliance that was indistinguishable from healthy young
      individuals suggesting that lifelong exercise training prevented this stiffening; c) even
      prolonged and intense exercise training started after age 65 failed to reverse age-related
      cardiac and vascular stiffening; d) cardiac stiffening begins in middle age (45-64) and can
      be substantially prevented by training 4-5 days/wk. The primary objective of this project, is
      therefore to identify sedentary individuals aged 45-64, and initiate an exercise program
      carefully designed to maximize effects on cardiovascular compliance and function. After this
      aim is accomplished, we will have established a novel, practical exercise training strategy
      designed to prevent the cardiovascular stiffening with aging, improve the functional capacity
      in our aging population, and ultimately to prevent Heart failure with preserved Ejection
      Fraction. Such a determination would have enormous public health significance since this
      condition is quite difficult to treat once established.

      Hypothesis: The investigators hypothesize that exercise training implemented 4-5 times/week
      for 2 yrs in sedentary middle aged men and women (45-64yr) will improve cardiac and vascular
      compliance to a degree equivalent to life-long exercisers (and sedentary young). The
      investigators will perform invasive and non-invasive assessment of cardiovascular structure
      and function before and after an exercise program involving high intensity aerobic intervals,
      lower intensity endurance ("base training"), and strength training.

      Specific Aim: To test our hypothesis, there will be two groups of previously sedentary
      subjects, ages 45-64 for 2 years, with the following interventions: 1) subjects undergoing
      prolonged endurance/interval/strength exercise training; and 2) yoga/balance control.

      A comprehensive set of "Baseline Testing" (prior to the two year intervention) and "Follow-up
      Testing" (after the two year intervention) will take place to assess the effects of the
      intervention. This testing will include submaximal and maximal exercise testing as well as
      comprehensive invasive (right heart catheterization) and non-invasive (ultrasound) measures
      of cardiac mechanics, relaxation and morphology. From these data, the following indices of
      diastolic and systolic function will be generated: Starling and pressure/volume curves;
      calculations of left ventricle wall stress and strain; and measurements of flow propagation
      velocity, ejection fraction and relaxation velocity.
    

Intervention name(s): Aerobic and strength training group; Balance and flexibility group
Intervention type(s): Behavioral; Behavioral
Intervention description(s): A exercise training program will be developed individually for each subject with the goal of increasing duration and intensity consistent with modern training techniques. Workouts will vary with respect to mode (walk, cycle, swim), duration (30-60 minutes), and intensity (base, interval, recovery) to optimize the training response. Each subject will be assigned a personal trainer and a heart rate monitor so that every session is carefully tracked and recorded. For intervals, we will use the novel high intensity aerobic intervals (HAIT). Subjects will also perform strength training 1-2 days/week.; For the balance and flexibility group, subjects will be encouraged to participate in yoga/tai chi/pilates classes that is approved by one of the exercise physiologists on the research team. The goal for this group is exercise classes that will be of benefit to them, but that will not include sustained aerobic, endurance exercise. In place of a group exercise class, subjects will have the option of purchasing videos for home use. The subjects will be encouraged to participate in some form of non-endurance training at least 3 days per week. Each subject will receive an exercise log in which they will be expected to record their training.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Exercise; Exercise tolerance; Aging; Physical activity