Project Summary
It is predicted that 13.8 million US adults will live with Alzheimer’s disease (AD) by 2050. Physical activity
(PA) is imperative to prevent or delay the onset of AD. However, adherence to the national PA guidelines
steeply declines after ages 60-65. Fewer than 20% of US older adults adhere to the national guidelines for
multicomponent PA - aerobic exercise (AE) at moderate intensity and strength training (ST). Thus, there is an
urgent need to promote multicomponent PA among low-active older adults. A major challenge to promoting
multicomponent PA is that most older adults experience a negative affective response to moderate-intensity
AE and ST. This negative affective response is a critical barrier to maintenance of regular PA because, in
general, people are unlikely to continue a behavior that results in immediate displeasure. Interestingly, listening
to music during acute bouts of AE and ST increases positive affect and reduces perceived exertion. However,
for these benefits to translate to long-term adherence, music alone is not sufficient. In a feasibility study
(N=33), walking-for-exercise with a sonically enhanced music playlist in the form of Rhythmic Auditory
Stimulation (RAS) – an application of pulsed, tempo-synchronous, auditory stimuli (e.g., beat-accented music)
for the facilitation of rhythmic body movement – nearly doubled the weekly volume of PA and caloric
expenditure in midlife-to-older patients undergoing cardiac rehabilitation whereas standard music without RAS
had little effect on PA outcomes. To date, this proof-of-concept has not been fully tested and the underlying
psychological mechanisms of RAS remain unknown. Thus, we propose to test whether RAS enhances
affective responses to PA and thereby promotes long-term PA behaviors among older adults. In the R61 and
R33 phases, participants will undergo an exercise intervention (EX) consisting of ST for 3 days/week and brisk
walking for AE for >150 min/week over 6 months. The EX is designed to foster the independent maintenance
of regular PA through a gradual withdrawal of supervised training (3 days/week for 2 months, 1 day/week for 2
months, and unsupervised for 2 months). The independent variable will be random assignment into the EX
alone or EX+RAS. In the R61 phase, we will conduct an RCT to explore the preliminary effects of RAS on
affective and behavioral responses to the EX among non-demented, low-active, older adults (N=40) aged 65-
79 (Aim 1). Using ecological momentary assessment (EMA), we will test the hypothesis that adding RAS to the
EX leads to a more positive affective response to PA, lower perceived exertion, and greater weekly volumes of
PA over 6 months. Treatment adherence and satisfaction will be assessed to determine the acceptability of the
interventions. If milestones are met, we will proceed to the R33 phase and conduct a fully-powered RCT with
the same design and population (N=130). We will retest Aim 1 with this second larger sample and will assess
Aim 2 which is a test of the mechanistic hypothesis that the effects of RAS on the weekly volumes of PA are
mediated by positive affective response to PA and lower perceived exertion.