Affective Responses to Physical Activity: A Novel Intervention Target for Increasing Physical Activity
Phase: NA
Conditions: Physical Activity, Obesity
Sponsor: The Miriam Hospital

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Feelings about Exercise: Protocol 
NCT03598647 
1/23/19 
 
 

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Background and objectives 
Despite the numerous health benefits of regular physical activity (PA), >50% of adults 
are insufficiently active. Understanding why some individuals choose to engage in PA 
while others do not is important for informing the development of future PA 
interventions. Previous research has demonstrated that those who have more positive 
affective responses to exercise (i.e., the pleasure or displeasure experienced with PA) 
are more likely to exercise in the future. However, an interesting paradox is that most 
people generally ‘feel good’ post-exercise This begs the questions, if exercise makes 
people feel good, why don’t more people exercise? The answer may lie in one’s 
memory of how exercise makes them feel. 
 
This study seeks to compare exercisers and non-exercisers on their affective responses 
to exercise, which includes pre-, during, and post-exercise affect, memory of during and 
post-exercise affect, and anticipated affect towards a future exercise session. It is 
hypothesized that compared to regular exercisers, non-exercisers will have a more 
negative memory of how exercise made them feel, and as a result, also have more 
negative anticipated affect towards a future exercise session. Further, this study seeks 
to pilot an intervention to improve affective response to exercise among the group of 
non-exercisers. It is hypothesized that non-exercisers randomized to an affect-based 
intervention will have a more favorable affective response to exercise following the 
intervention compared to those randomized to the control intervention (e.g., basic PA 
recommendations).  
 
Participants 
A total of 59 individuals with overweight/obesity (BMI 25-40 kg/m2), who were weight 
loss seeking, and between the ages of 18-60 were recruited via self-referral from 
Internet advertisements. Interested individuals completed a phone screen questionnaire 
to determine initial eligibility. During this screening, trained research assistants queried 
potential participants on their moderate-to-vigorous intensity PA (MVPA) over the 
previous 6 months and a recent ‘typical’ week. If average MVPA was <30 min/week, the 
individual was classified as a ‘non-exerciser’, if average MVPA was ≥150 min/week, the 
individual was classified as an ‘exerciser’. Individuals reporting an intermediate amount 
of MVPA (30 to <150 min/week) were ineligible for this study as the goal was to target 
distinctive groups of exercisers vs. non-exercisers. Exclusion criteria included conditions 
limiting ability to exercise, history of coronary artery disease (i.e., myocardial infarction), 
stroke, diabetes, pulmonary disease (e.g., COPD), uncontrolled hypertension (i.e., 
resting BP ≥140/90 mmHg), use of any medication that would affect heart rate (HR; 
e.g., beta blocker), current enrollment in a weight loss treatment program, history of 
bariatric surgery, or women who were nursing/pregnant, 
 
Study overview 
Individuals deemed eligible based upon the phone screen attended an in-person 
orientation session in order to learn about the study in greater detail and to provide 
informed consent in accordance with guidelines set forth by the Internal Review Board 
of the Miriam Hospital. Upon consenting, participants completed a baseline 
assessment, which included measures of BMI, fitness, and 1 week of objective physical 

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activity (PA) monitoring. Participants then returned to the laboratory for Exercise 
Session 1, in which they walked on a treadmill for 30 minutes at a moderate intensity. 
Prior to exercise they reported on anticipated affect (i.e., how they expect the upcoming 
exercise bout to make them feel), and momentary affect was assessed before, during, 
and after exercise. In days 1, 3, and 7 following the exercise session, participants were 
asked to report on their recalled affect via text messaging. They then returned to the 
laboratory to complete an identical exercise session (Exercise Session 2). Following the 
completion of the final post-exercise affect measurement, ‘non-exercisers’ randomly 
received 1 of 2 PA interventions and then completed additional study measures 
(described in detail below), while ‘exercisers’ did not complete any additional study 
procedures beyond this point.  
 
Baseline Visit: BMI, Fitness Test, Objective PA Measurement: Prior to participating 
in Exercise Sessions 1 and 2, participants completed the following baseline assessment 
measures.  
 
BMI.  Weight was measured to the nearest 0.1 kg using a calibrated digital scale and 
height was measured to the nearest 0.1 cm using a wall-mounted stadiometer. Body 
mass index (BMI) was calculated as kg/m2.  
 
Fitness Test. Fitness was measured via a sub-maximal graded exercise test (GXT). 
Participants walked on the treadmill at 3.0 mph and the speed and incline were 
increased every three minutes until 75% of age-predicted maximal HR was achieved. 
Total time spent on the treadmill (in seconds) was used as an indicator of fitness. The 
purpose of this GXT was to allow participants to gain familiarity with walking on a 
treadmill and assist in determining the starting treadmill grade for the following exercise 
visit.  
 
Objective PA Measurement. While participants were deemed eligible for this study 
based upon self-report measures of PA, direct PA monitoring was also performed to 
confirm that ‘exercisers’ and ‘non-exercisers’ significantly differed on MVPA. All 
participants wore a previously validated activity monitor (Sensewear Armband, Body 
Media Inc., Pittsburgh PA) for 1 week and were asked not to alter their activity levels 
during this period. The monitor is worn on the upper arm and assesses movement and 
energy expenditure, however the device does not provide any information or feedback 
to participants. Minute-by-minute data were collected, and using proprietary algorithms, 
MET values were computed for each minute the device was worn. Exercise groups 
were compared on time spent engaging in bout-related MVPA (≥ 3 METs, ≥10 min). 
 
Exercise Session 1 
 
Exercise Protocol. Following completion of all assessment measures, participants 
returned to the laboratory for Exercise Session 1. Upon arrival, participants were given 
a detailed description of the upcoming exercise protocol and were equipped with a HR 
monitor. Immediately prior to the start of the exercise bout, participants were asked to 
report their pre-exercise momentary affect using the Feeling Scale and their anticipated 

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affect towards the upcoming exercise bout using a visual analogue scale (see below for 
additional detail on affect measures). They then completed the exercise protocol which 
consisted of a 2-minute warm-up, followed by 30 minutes of moderate-intensity walking 
(70-75% of age-predicted maximal HR), and a 2-minute cool-down. This exercise 
duration and intensity was chosen because it is consistent with the American College of 
Sports Medicine’s exercise guidelines, and is feasible for individuals with 
overweight/obesity. Starting exercise intensity was estimated using HR data from the 
baseline fitness test. Heart rate was monitored every minute and the treadmill grade or 
speed was adjusted by trained research staff if the subject’s HR fell outside the target 
range for two consecutive minutes. Affect was assessed every 5 minutes during 
exercise, immediately post-exercise, and 15 minutes following the completion of the 
exercise bout.  
 
 
Assessment of momentary affect. The Feeling Scale (FS; Hardy & Rejeski 1989) was 
used to assess momentary affect before, during and after exercise. This single-item 
measure asks participants to rate how they feel ‘at the present moment’ on an 11-point 
scale ranging from -5 (very bad) to +5 (very good). Pre-exercise affect was assessed as 
individuals stepped onto the treadmill but before the exercise was started. During 
exercise affect was assessed every 5 minutes during the exercise bout (excluding 
warm-up), and post-exercise affect was assessed immediately after the conclusion of 
the exercise protocol and exactly 15 minutes later. 
 
Assessment of anticipated affect. Prior to the exercise sessions anticipated affect was 
assessed using a 100mm visual analog scale (VAS). This method for assessing 
anticipated affect requires participants to denote their response on a continuous line 
(anchored by ‘very bad’ and ‘very good’ similar to the Feeling Scale used for measuring 
current affect) but does not quantify affect with a numerical response (e..g, “2”), thereby 
eliminating potential for participants to provide subsequent affect ratings that are simply 
repetitions of their predictions. Participants were specifically asked “How do you 
anticipate feeling during exercise?” and “How do you anticipate feeling after exercise?”. 
 
Affective Recall and Memory Bias 
In the week following Exercise Session 1, all participants were asked to maintain their 
typical daily routines of either exercising or not exercising and respond to an online 
questionnaire assessing their recall of their own affective responses to the exercise 
session. These questionnaires were completed 1, 3, and 7 days following the exercise 
session, and participants responded to the questionnaire by clicking on a link provided 
via text message. In order to avoid direct recall of responses provided on the Feeling 
Scale, a VAS was used. On days 1, 3, and 7, participants were asked to reflect upon 
their Exercise Session 1 by responding to following question; “How do you remember 
feeling overall?” and this was considered an indicator of global affective recall. 
Following this response on day 7 only, participants were asked to further delineate how 
they remembered feeling during exercise, and post-exercise. Memory bias was 
assessed by converting VAS recall values to corresponding FS values and then taking 
the discrepancy between recalled and actual FS values during and post-exercise (e.g., 
recalled during exercise affect [assessed 7 days post-exercise] minus actual during 

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exercise affect [average of Feeling Scale scores every 5 minutes during exercise]. A 
negative number indicates that participants remembered feeling less positive during 
exercise than they actually felt. Memory bias for post-exercise affect was computed in a 
similar manner. 
 
Exercise Session 2  
In order to collect data on anticipated affect after participants had experienced one 
laboratory exercise session, all participants were asked to return to the laboratory for a 
second exercise session at least 1 week following Exercise Session 1. Exercisers were 
compensated $50 for participation in the study, while non-exercisers were randomized, 
and received a brief PA intervention (described below). 
 
Randomized Controlled Trial for Non-Exercisers 
Immediately following Exercise Session 2, all non-exercisers were randomized to a 
brief, affect-based PA intervention (INT; n=15) or an educational PA intervention, which 
served as the control condition (CON; n=15).  
 
Components common to both the Affect Intervention and Control Condition. Participants 
in both arms were informed of the national PA guidelines (150 min/wk of MVPA) and 
were encouraged to meet these guidelines. They were also provided with general 
information regarding the physiological and psychological health benefits of regular 
exercise. They were educated on what types of activities were considered moderate-
intensity and how to gauge this intensity on their own. Finally, they were asked to reflect 
on their reasons for wanting to become more physically active.  
 
Affect Intervention. In addition to the educational content described above, participants 
assigned to this group received a brief, affect-based intervention with a PhD-level 
interventionist in which they were taught cognitive strategies designed to make their 
affective recall more positive. First, each participant was shown a graph of normative 
data from studies using the Feeling Scale during and post-exercise. This was used in 
the current study specifically to normalize the experience of reductions (“dips”) in 
positive affect during exercise and to highlight the general positive affect produced by 
moderate-intensity exercise. The interventionist then shared a graph illustrating the 
participant’s own affective trajectory from Exercise Session 1. The interventionist 
discussed this trajectory with the participant, pointing out the moments that were most 
positive, and using open-ended questions to probe the participants’ feelings about these 
moments and these data. Participants were then shown on the graph their recalled 
affect for the same exercise session. Time was spent pointing out discrepancies or 
biases in recalled affect and actual affect. Participants were asked specific questions 
aimed at increasing their awareness of their recall (e.g., why do you think you 
remembered exercise in this way? When you report on how you remember feeling in 
response to exercise, what do you think sticks out most in your mind and contributes to 
your response? Do you think you are focusing more on how you felt during or after 
exercise?). Third, adopting strategies from positive psychology to draw participants’ 
attention to positive outcomes from a bout of exercise, participants were asked to write 
down any positive feelings they experienced during or as a result of the previous 

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exercise session (e.g., improved mood, feeling energized, feeling accomplished/proud, 
or feeling good about doing something beneficial for the body). They then shared their 
responses with the interventionist and participants were encouraged to think about 
these positive experiences, feelings, and motivations for engaging in exercise often, and 
specifically during the next exercise session. 
 
Post-intervention assessment 
Non-exercisers in both arms were informed they could increase their PA following 
Exercise Session 2 if they desired, and they were given the Sensewear armband to 
wear for 1 week to objectively assess whether there was an intervention effect on bout-
related MVPA. Further, during the week following Exercise Session 2, all non-exercisers 
were asked to complete recalled affect questionnaires for Exercise Session 2 at 1, 3, 
and 7 days following the session, as was done previously.  
 
Exercise Session 3 
One to two weeks following Exercise Session 2, non-exercisers from both the control 
and intervention groups returned to the laboratory for a third exercise session (Exercise 
Session 3). This session was identical to the previous exercise sessions and measures 
of anticipated affect, pre-, during, and post-exercise affect were obtained. All non-
exercisers attending Exercise Session 3 (INT and CON) were compensated $50 for 
their time.