Effects of a Bicycling Intervention on Cognitive Skills and Cardiovascular Health
Condition: Sedentary Lifestyle
Study type: Interventional

Summary: 
      Although exercise is known to delay cognitive decline and decrease our risk of Alzheimer's
      Disease, there is a lack of understanding of how exercise protects the aging brain. The
      proposed research takes a novel approach to this problem by testing the concept that there
      are acute, direct effects of exercise in the same brain regions that are affected by chronic
      exercise training. If the investigators are successful, the acute paradigm will allow us to
      determine the critical exercise parameters that modulate brain function in humans using only
      a single exercise dose.
    

Detailed description: 
      Given the rising proportion of older adults worldwide and the progressive decline in brain
      function with advancing age, there is a pressing need to develop novel interventions that
      protect the aging brain. The predominant approach for implementing exercise training to
      improve brain function is to increase cardiovascular fitness. However, there is mixed
      empirical support for the effectiveness of this approach. Further, there are also acute
      effects of exercise within one hour of the cessation of a single exercise session. These
      effects occur before adaptations related to fitness could occur and animal studies have shown
      they occur in the same brain regions that benefit from longer-term exercise training.
      Therefore, the investigators propose the acute paradigm is a tool to probe this early, direct
      response from exercise in order to determine how best to maximize the long-term benefit of
      exercise training on the aging brain. This presents a critical need to determine the
      mechanistic relation between acute and long-term effects of exercise on the aging brain. Our
      long-term goal is to determine how exercise protects the brain from the adverse effects of
      aging. In turn, our specific objective in this R21 proposal is to support or refute the
      concept that a single session of exercise produces acute increases in functional synchrony of
      clinically relevant brain networks that are related to accrued exercise-training effects in
      the same brain systems. Our central hypothesis is that the effects of moderate intensity
      exercise will increase the functional synchrony of the hippocampus with the Default Mode
      Network, and the Prefrontal Cortex with the Fronto-Executive Network, in the same fashion as
      a 12-week moderate intensity exercise training program. This hypothesis is based on data
      showing acute effects of exercise on factors related to neuronal plasticity and excitability
      in the same brain regions that show long-term effects of exercise in animals. The
      contribution of the proposed research is significant because it will determine the extent to
      which the acute exercise paradigm can provide insight into how regular exercise protects the
      brain from adverse effects of aging. The proposed research is innovative because for the
      first time the investigators will examine the overlapping neural systems and outcomes
      associated with acute and chronic exercise in the same individuals. Overall, success in this
      project will enable future research to study how varying exercise parameters such as mode or
      intensity affect exercise-induced change in brain function and the timecourse of these
      effects, as well as the neurobiological mechanisms associated with the direct effects of
      exercise on the aging brain.
    

Intervention name(s): Cycling
Intervention type(s): Behavioral
Intervention description(s): The experimental group will complete a 3 month exercise program that includes working up to cycling at a moderate intensity for 50 minutes/session 3 times a week. The comparison group will complete a 3-month exercise program that includes intermittent cycling (alternating between passive and moderate intensity) for 50 minutes/session 3 times a week. Both groups will exercise in our laboratory at Spence Labs, and will be supervised by an exercise trainer that is trained in working with elderly and special populations.
Other intervention name(s): Exercise
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Basic Science
Keywords: physical activity; aging; cognition; brain; exercise