Cerebral Blood Flow during Interval and Continuous Exercise in Young and Old Men

Abstract

Purpose Aging is associated with impaired cerebral blood flow (CBF) and increased risk of cerebrovascular disease. Acute increases in CBF during exercise may initiate improvements in cerebrovascular health, but the CBF response is diminished during continuous exercise in older adults. The effect of interval exercise for promoting increases in CBF in young and old adults is unknown. Methods We compared middle cerebral artery blood velocity (MCAv), end-tidal CO2 (PETCO2) and blood pressure (mean arterial pressure [MAP]) during intensity- and work-matched bouts of continuous (10-min 60%W max, followed by 10-min rest) and interval cycling (10 × 1-min 60%W max, separated by 1-min rest) in 11 young (25 ± 3 yr) and 10 old (69 ± 3 yr) men. Results Middle cerebral artery velocity was higher during continuous compared with interval exercise in the young (P < 0.001), but not in the old. This trend was also seen for changes in PETCO2. Although absolute MAP was higher in the old, the relative rise (%∆) in MAP was similar between age groups and was greater during continuous exercise than interval. When we assessed the total accumulated change in MCAv (area under curve: exercise + recovery), it was higher with interval compared with continuous exercise in both groups (P = 0.018). Conclusion These findings suggest that interval exercise may be an effective alternative for promoting acute increases in CBF velocity, particularly in those older adults who may have difficulty sustaining continuous exercise.

Post-exercise Hypotension Following a Single Bout of High Intensity Interval Exercise vs. a Single Bout of Moderate Intensity Continuous Exercise in Adults With or Without Hypertension: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

“…Authors of 13 studies were contacted twice by e-mail over a 1-month period asking to provide missing data in cases of incomplete reporting. After 1 month, five authors provided more detailed information (Mourot et al, 2004 ; de Carvalho et al, 2014 ; Morales-palomo et al, 2017 ; Pimenta et al, 2019 ), two authors reported no access to the data (Scott et al, 2008 ; Lacombe et al, 2011 ), one author reported the lack of these data (Klein et al, 2019 ), and five authors did not reply.…”

The Acute Effects of Time-Varying Caloric Vestibular Stimulation as Assessed With fMRI

“…We are not aware of other neuromodulation device studies that produce such effects. However, the exercise literature, in particular studies of high intensity interval training, does contain examples of time-varying modulation of hemodynamics ( Klein et al, 2019 ). The well-known benefits of aerobic exercise on brain health ( Barnes, 2015 ) makes it an interesting model for comparison as we address future clinical work utilizing tvCVS.…”

The effect of age on cerebral blood flow responses during repeated and sustained stand to sit transitions

“…The primary aim of this study was to investigate the effect of age on the cerebral pressure–flow relationship during repeated stand‐to‐sit transitions. Our main interest in this was to better understand the smaller increase in MCAv, relative to the greater increase in blood pressure, that is consistently reported during exercise in older people (Fisher et al, 2013; Fluck et al, 2014; Klein et al, 2019; Ward et al, 2018). Repeated stand‐to‐sit transitions reflect a common daily movement and are a well‐accepted method to induce dynamic blood pressure changes, which we also demonstrated (Figure 1) (Claassen et al, 2016).…”

“…Aging and age‐related cerebrovascular diseases are associated with a decline in resting cerebral blood flow, commonly characterized by a lower middle cerebral artery velocity (MCAv), and reduced cerebrovascular function (Ainslie et al, 2008; Bailey et al, 2013; Beek, Olde Rikkert, Pasman, Hopman, & Claassen, 2010). Furthermore, the transient elevation in MCAv during exercise is attenuated in older adults (Fisher et al, 2013; Fluck et al, 2014; Klein, Bailey, Abeln, Schneider, & Askew, 2019; Marsden et al, 2012). Cerebral blood flow control is multifactorial, and it is therefore difficult to isolate the relative regulatory contributions of neural, metabolic, and cardiovascular factors.…”

“…Changes in mean arterial blood pressure (MAP) are believed to be a key driver for the dynamic MCAv response to exercise. However, in older adults the lower MCAv response to exercise is often reported in the presence of larger increases in MAP compared with young adults (Fisher et al, 2013; Fluck et al, 2014; Klein et al, 2019; Marsden et al, 2012). This raises the possibility that an impaired responsiveness to transient or repetitive increases in blood pressure may contribute to the lower cerebral blood flow with aging.…”