Impact of ischemic preconditioning on exercise blood flow and vasoconstriction in older adults

Exercise is a key pillar of physical wellbeing and is beneficial across all ages. During exercise, active muscles require oxygen and nutrients, which are delivered by blood pumping through the circulatory system. Without adequate blood flow to contracting muscles, the capacity to perform exercise becomes impaired. Older adults tend to have reduced exercise blood flow as well as changes in nervous system function. The sympathetic nervous system (SNS) is one of two divisions of the autonomic nervous system and is involved in the fight or flight response. Older adults often demonstrate higher SNS activity and a diminished ability to offset sympathetic signals in the skeletal muscle during exercise, which can restrict blood flow and reduce exercise capacity. Therefore, identifying interventions to help with these age-related impairments will make exercise more tolerable. The present study explored an intervention known as ischemic preconditioning (IPC) which involves repeatedly restricting and then restoring blood flow over several minute intervals. During the study, subjects participated in mild intensity exercise and SNS stimulation while skeletal muscle blood flow responses were measured before and after IPC. The results of the present study provide evidence that IPC is effective in improving exercise blood flow in older adults. Additionally, the results suggest improvements in skeletal muscle blood flow following IPC are likely because of the improved ability to dampen the effects of the SNS activity during exercise. Our hope is that this intervention will lead to functional improvements associated with activities of daily living in older adults.