Brain Plasticity 2 (2016/2017) 127–152
DOI 10.3233/BPL-160040
IOS Press
127
Review
The Effects of Acute Exercise on Mood,
Cognition, Neurophysiology,
and Neurochemical Pathways: A Review
Julia C. Basso and Wendy A. Suzuki
∗
Center for Neural Science, New York University, New York, NY, USA
Abstract. A significant body of work has investigated the effects of acute exercise, defined as a single bout of physical activity,
on mood and cognitive functions in humans. Several excellent recent reviews have summarized these findings; however, the
neurobiological basis of these results has received less attention. In this review, we will first briefly summarize the cognitive
and behavioral changes that occur with acute exercise in humans. We will then review the results from both human and
animal model studies documenting the wide range of neurophysiological and neurochemical alterations that occur after a
single bout of exercise. Finally, we will discuss the strengths, weaknesses, and missing elements in the current literature, as
well as offer an acute exercise standardization protocol and provide possible goals for future research.
Keywords: Running, affect, prefrontal cortex, hippocampus, electroencephalography, neuroimaging, neurochemistry,
neurogenesis
INTRODUCTION
The positive influence of exercise on mood and
cognition across the lifespan has become a topic of
much excitement [1]. In particular, abundant data
suggest that physical activity can reduce the risk of
various neurological diseases and protect the brain
from the detrimental effects of aging [2–4]. Ani-
mal models have focused mainly on the effects
of long-term exercise (i.e., weeks to months of
increased exercise) on hippocampal function, with
special emphasis on exercise-induced adult hip-
pocampal neurogenesis and hippocampal-dependent
learning and memory [5, 6]. Studies in rodents have
also documented the neuroanatomical, neurochemi-
cal, and cellular/molecular changes associated with
∗
Correspondence to: Wendy A. Suzuki, Ph.D., 4 Washington
Place, New York, NY 10003, USA. Tel.: +1 212 998 3734; Fax:
+1 212 995 4011; E-mail: wendy@cns.nyu.edu.
long-term exposure to exercise [7, 8]. In humans,
both behavioral and functional imaging approaches
have started to identify the neuroanatomical systems
modulated by long-term increases in exercise. The
most commonly reported area to undergo improve-
ment is the prefrontal cortex, with exercise-induced
enhancements observed in attention and other execu-
tive functions [9]. As well as for improving cognition
in children and healthy adults, these long-term effects
of exercise are of particular interest for their possi-
ble role in improving cognitive function during aging
[10–12]. As we age, cognitive decline, though not
inevitable, is a common occurrence resulting from
the process of neurodegeneration. In some instances,
neurodegeneration results in mild cognitive impair-
ment or more severe forms of dementia including
Alzheimer’s, Parkinson’s, or Huntington’s disease.
Because of the role of exercise in enhancing neu-
rogenesis and brain plasticity, physical activity may
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128 J.C. Basso and W.A. Suzuki / The Effects of Acute Exercise on Mood
serve as a potential therapeutic tool to prevent, delay,
or treat cognitive decline. Indeed, studies in both
rodents and humans have shown that long-term exer-
cise is helpful in both delaying the onset of cognitive
decline and dementia as well as improving symptoms
in patients with an already existing diagnosis [13–15].
In addition to the robust literature on the effects
of long-term exercise on brain function, a grow-
ing literature has also examined the influence of
a single bout of exercise, termed “acute exercise”,
on human behavior. A recent set of excellent meta-
analyses has detailed a range of behavioral changes,
concluding that acute exercise has an overall small
positive effect on cognitive functioning, especially
in areas of prefrontal cortex-dependent cognition
[9, 16–19]. Additionally, acute exercise has been
shown to enhance affective, mood, and emotional
states [20]. Because of the lack of a general criteria
regarding low-, moderate-, and high-intensity aero-
bic exercise, human studies have utilized a range of
acute exercise protocols. This has led to a diverse
set of findings, which are highlighted throughout
the manuscript; implications for such findings are
considered in the discussion. For this review, we
have primarily focused on aerobic exercise, but have
included some studies that utilize resistance exer-
cise. Additionally, we have mainly reviewed studies
in healthy adults, but have included some discussion
of the effects of acute exercise in individuals with
various diseases/disorders. Finally, our focus has cen-
tered around the effects of acute exercise on behaviors
dependent on the prefrontal cortex, mood, and stress
responses, but a small collection of literature is start-
ing to reveal that acute exercise may be beneficial on
a variety of other brain processes as well, including
motor learning and memory dependent on striatal-
cortical circuits.
To maximize results, the majority of rodent stud-
ies investigating the effects of physical activity on
brain structure and function utilize running protocols
typically lasting three weeks or more. Therefore,
acute exercise, as it is used in humans (e.g., approx-
imately one hour of exercise), is rarely studied in
rodents. The majority of studies that have utilized a
single bout of exercise typically examine the effects
on neurochemical changes. Many fewer studies have
examined the behavioral effects of acute exercise
in rodents. Because of the limited number of these
studies, we have included those that investigated the
effects of one week or less of exercise, which is con-
sidered an acquisition time period for running in the
rodent [21], on behavioral and brain outcomes.
The goal of this review is to summarize the
wide range of neurophysiological and neurochemical
changes that have been described after an acute bout
of exercise, from studies in both animal models and
human subjects, and to link these changes to a range
of behavioral effects that have been described mainly
in humans. As chronic exercise is ultimately the result
of regular bouts of acute exercise, understanding the
changes induced by a singular bout of exercise may
provide novel insight into how to interpret and even
approach the study of the effects of chronic increases
in physical exercise on cognitive function.
THE EFFECTS OF ACUTE EXERCISE
ON COGNITION, MOOD, AND STRESS
RESPONSES IN HUMANS
A comprehensive set of narrative [22–26] and
meta-analytic reviews [9, 16–19] that focused on
the effects of acute exercise on cognition in peo-
ple concluded that acute exercise has an overall
small positive effect on cognitive functioning. How-
ever, the individual studies supporting this conclusion
are highly variable, demonstrating behavioral effects
ranging from strongly positive to detrimental. One
of the main reasons this spread of results exists is
because of the diverse exercise regimens that have
been utilized. Notably, there is currently no stan-
dardized way to assess the influence of exercise on
cognitive functioning, which has resulted in a wide
variety of physical activity protocols that differ in
the critical factors of format (i.e., the type of exer-
cise used), intensity, and duration (but see Table 2).
Despite this wide range of testing parameters, three of
the most consistent effects reported are (1) improve-
ments in cognitive tasks that depend primarily on
the prefrontal cortex [27], (2) enhancements in mood
state [28, 29], and (3) decreases in stress level [30]
(Fig. 1A). More limited evidence exists to show that
acute exercise improves long-term memory [31–34]
and associative memory [35, 36] dependent on the
hippocampus, learning [37] and retention [38, 39]
of motor skills dependent on the striatum, emotional
memory dependent on the amygdala [40, 41], and
skills dependent on both the primary visual and motor
cortices [42].
The tasks most often used to test the effects of
acute exercise on cognition are those that assess the
functions of the prefrontal cortex, including atten-
tion and perception tasks that focus primarily on
reaction time, and both verbal and visual working
J.C. Basso and W.A. Suzuki / The Effects of Acute Exercise on Mood 129
Fig. 1. The Time Course of Behavioral, Functional, Physiological, and Neurochemical Effects of Acute Exercise.
130 J.C. Basso and W.A. Suzuki / The Effects of Acute Exercise on Mood
Table 1
Prefrontal cortex-dependent tasks that show improvement with
acute exercise
Stroop Color and Word Task
Eriksen Flanker Task
N-Back Task
Trail Making Task A and B
Wisconsin Card Sorting Task
Hopkins Verbal Learning Task
Symbol Digit Modalities Task
Go/No Go Task
Stop Signal Task
Simon Task
Random Number Generation Task
Tower of London Task
Digit Span Task
Reading Span Task
Operation Span Task
memory tasks. These include the Eriksen Flanker
Task, the Stroop Color and Word Task, the Go/No Go
Task, and the N-back Task among others (Table 1).
Collectively, this literature shows that executive func-
tions including attention, working memory, problem
solving, cognitive flexibility, verbal fluency, decision
making, and inhibitory control receive the most ben-
efit from acute exercise [9], with effects lasting for up
to two hours post-exercise cessation (Fig. 1A) [27].
Moreover, many of these neuropsychological assess-
ments measure several aspects of behavior including
both accuracy of performance and speed of process-
ing. McMorris and Hale performed a meta-analysis
examining the effects of acute exercise on both accu-
racy and speed of processing, revealing that speed
significantly improved post-exercise, with minimal
or no effect on accuracy [17]. These authors con-
cluded that increasing task difficulty or complexity
may help to augment the effect of acute exercise on
accuracy.
A major factor that has been shown to influence
the cognitive effects of acute exercise in people is
exercise intensity. Yerkes and Dodson’s law sug-
gests that an inverted-U relationship exists between
arousal and performance [43, 44]. Based on this idea,
which predicts that moderate-, but not low- or high-,
intensity exercise supports enhanced cognition, the
majority of studies have utilized moderate-intensity
exercise protocols. However, in a comprehensive
meta-analysis, Chang and colleagues found that
exercise intensities ranging from very light (<50%
MHR) to very hard (>93% MHR) have all been
reported to improve cognitive functioning [9]. Some
studies have examined the effects of varying doses
of exercise [34, 45–48]. One study, for example,
that compared the effects of various maximal resis-
tance regimens (none versus 40%, 70%, or 100%
of 10-repetition maximum) on cognitive functioning
revealed that different intensities of exercise might
differentially improve distinct types of brain func-
tions. Specifically, moderate-intensity exercise may
be more beneficial for executive functions (Tower of
London and Stroop), whereas high-intensity exercise
may be more beneficial for information processing
(Paced Auditory Serial Addition) [45, 49]. Another
study in individuals with Down syndrome investi-
gated the effects of 20 minutes of moderate- (50–74%
age-predicted MHR) versus high-intensity (75–85%
age-predicted MHR) treadmill walking on informa-
tion processing speed (assessed by a choice reaction
time test) and executive function (attention shift-
ing assessed by the dimensional change card sorting
test and inhibitory control assessed by the knock-
Table 2
Proposed acute exercise study standards
Acute Exercise Measurement and Category Values
1) Duration (measured in minutes)
Short 0 to 15 minutes
Moderate 16 to 45 minutes
Long 46 minutes or longer
2) Intensity (measured in percentage of VO
2
max)
Low ≤39
Moderate 40 to 59
High ≥60
3) Percevied exertion
Measured by the Borg Ratings of Perceived Exertion Scale 6 to 20
4) Exercise index
A combined value of duration, intensity, and perceived exertion
Calculation: (% of hour+%ofVO2max+%ofscale) / 3
Duration, intensity, and perceived exertion refer to the exercise session itself, excluding the warmup and
cooldown. See Supplementary Figure 1 for more details and a data collection template.
J.C. Basso and W.A. Suzuki / The Effects of Acute Exercise on Mood 131
tap test) [50]. In this population, moderate-intensity,
but not high-intensity, exercise facilitated informa-
tion process speed, whereas both moderate- and
high-intensity exercise were beneficial for inhibitory
control. Comparison of these studies indicate that
exercise type as well as health status of the individ-
ual may be important factors affecting the impact of
acute exercise on cognitive functioning.
Acute exercise is one of the most effective behav-
ioral techniques for self-regulation of mood in healthy
populations [51]. The effects of acute exercise on
mood state have been evaluated using a variety
of self-reported questionnaires such as the Profile
of Mood States (POMS; a questionnaire that mea-
sures tension, depression, anger, fatigue, confusion,
vigor and overall mood disturbance) and the Posi-
tive and Negative Affects Scale (PANAS) [28]. These
acute interventions have shown that exercise alle-
viates negative as well as enhances positive mood
states [52], with effects occurring immediately after
and lasting up to one day post-exercise cessation
[28, 29, 53] (Fig. 1A). As a large number of stud-
ies have utilized the POMS, one review sought to
determine the areas of mood that are most influ-
enced by acute exercise [54]. They found that the
largest improvements in mood were decreases in ten-
sion, depression, anger, and confusion. One study
examined the effects of acute moderate-intensity
exercise on affect using the circumplex model of
emotional state [55], which examines affect based on
two scales, valence and arousal, in young (19–39),
middle-aged (40–64), and older (65+) individuals
[56]. Results revealed that compared to a picture-
viewing control group, acute exercise significantly
increased high-arousal positive affect (HAP) (e.g.,
feeling energized) in all age groups. In contrast, low-
arousal positive affect (LAP) (e.g., feeling calm)
decreased for young adults but remained stable for
older adults. This study highlights the importance of
assessing the influence of acute exercise on both low-
and high-arousal affective states across different age
groups.
As the acute exercise protocols used in these stud-
ies vary dramatically, the best protocol for improving
mood is unclear. Some evidence exists, however,
to suggest that the most effective type of exercise
at producing mood improvements may be a work-
out experience that participants find enjoyable. For
example, in a study that compared varying exercise
intensities (low-, moderate-, and high-intensity) to
a self-chosen exercise intensity, the greatest mood
benefits in the form of high enjoyment scores after
exercise came from those who were able to choose
their own workout experience (based on the Physi-
cal Activity Enjoyment Scale) [57]. However, other
interpretations of this finding exist, and as this study
included only a small sample size (n = 10 for this
condition), future studies will be needed to assess
whether this finding is related to the subject’s sense
of control over the workout or the workout that best
matches the subject’s physical fitness or perceived
fitness level, for example.
In addition to improving mood, studies also
show that acute exercise is effective at reduc-
ing stress both on self-reported questionnaires [58]
and from anxiety-inducing procedures conducted
in the laboratory [59] (Fig. 1A). Acute exercise,
for example, decreases stress-related blood pressure
responses to laboratory-based stressors including
mental arithmetic, public speaking, neuropsycholog-
ical assessments, or the cold pressor test [30, 60].
Brownley and colleagues found that this effect was
most likely a result of acute exercise suppressing
the sympathetic nervous system response to stress
[61]. These studies suggest that acute exercise may
be an effective strategy for alleviating the psycho-
logical symptoms produced by an acute stressor.
Additionally, studies have shown that acute exer-
cise helps relieve symptoms associated with mood
and psychological disorders such as depression, anx-
iety, schizophrenia, and post-traumatic stress disorder
[62–64].
Summary of acute exercise-induced behavioral
changes (Fig. 1A)
A large collection of research in humans has shown
that a single bout of exercise alters behavior at the
level of affective state and cognitive functioning in
several key ways. In terms of affective state, acute
exercise decreases negative affect, increases positive
affect, and decreases the psychological and physio-
logical response to acute stress [28]. These effects
have been reported to persist for up to 24 hours after
exercise cessation [28, 29, 53]. In terms of cogni-
tive functioning, acute exercise primarily enhances
executive functions dependent on the prefrontal cor-
tex including attention, working memory, problem
solving, cognitive flexibility, verbal fluency, decision
making, and inhibitory control [9]. These positive
changes have been demonstrated to occur with very
low to very high exercise intensities [9], with effects
lasting for up to two hours after the end of the exercise
bout (Fig. 1A) [27].