The purpose of this study is to research the effects of exercising at high intensities for short periods of time on exercise tolerance and motivation.
The proposed research will investigate whether adding a treatment component that focuses on positive outcome expectations of a high-intensity interval training (HIIT) intervention produces greater improvements in psychological and physiological study outcomes. This project will yield empirical evidence that will inform how to help Americans meet physical activity guidelines; how to develop exercise programs that are more likely to promote exercise as a habit; and maintenance of health and a healthy body weight.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
SINGLE
Enrollment
66
Subjects will participate in high-intensity interval training (HIIT) with an additional treatment component to increase positive outcome expectations (POE) of exercise.
Subjects will participate in high-intensity interval training (HIIT) only.
USDA Grand Forks Human Nutrition Research Center
Grand Forks, North Dakota, United States
Change in relative reinforcing value (RRV) of physical activity
RRV of physical activity will be assessed by evaluating the number of responses (mouse button presses) a subject is willing to complete to gain access to physical activity or a sedentary alternative.
Time frame: Week 0, Week 6, Week 10
Changes in preference for intense physical activity and tolerance for exercise discomfort
Changes in preference for intense physical activity and tolerance for exercise discomfort will be assessed by self-report questionnaire responses to the Preference for and Tolerance of the Intensity of Exercise Questionnaire (PRETIE-Q). The PRETIE-Q measures preference for high intensity vs. low intensity exercise and ability to persist or tolerate the discomfort associationed with intense exercise. The PRETIE-Q consists of two subscales: Preference for Exercise Intensity and Tolerance of Exercise Intensity. Each subscale has 8 items rated on a 5 point response scale (range 8 - 40). Higher scores indicate greater preference for intense exercise and/or greater tolerance for exercise discomfort. Total scale scores are not used. Scale averages will be used.
Time frame: Week 0, Week 6, Week 10
Change in minutes of physical activity, as assessed by activity tracker
Minutes of physical activity will be assessed by having participants wear an Actigraph accelerometer for 7 days (minimum 10 hours per day) on the right hip.
Time frame: Week 0, Week 6, Week 10
Changes in quadriceps and hamstring (thigh muscle) strength assessed separately on each leg
After range of motion is determined, participants will engage in a series of extensions and flexions in which maximum velocity is set at 60°, 180°, and 300°.s±1 to determine each leg's peak torque as assessed by isokinetic dynamometer testing (Biodex System 4 Pro).
Time frame: Week 0, Week 6, Week 10
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Changes in aerobic fitness, as assessed using the Standardized Exponential Exercise Protocol (STEEP)
After a brief warm-up, participants will pedal on an ergometer 75-85 revolutions per minute (RPMs) at low resistance of approximately 2 metabolic equivalent of task (METs). The resistance will increase by 15% per minute until respiratory exchange ratio (RER) exceeds 1.0, maximum oxygen consumption (V02 max) is reached, or participant can no longer maintain pedaling speed.
Time frame: Week 0, Week 6, Week 10
Changes in anaerobic power, as during a Wingate anaerobic power exercise test
Following a brief warm-up, participants will be instructed to pedal on an ergometer as hard and as fast as they can for 30 seconds at a resistance of 1 watt·kilogram-1, followed by a cool-down period. Changes in anaerobic power, will be as assessed by as changes in power outputs in watts (rpm·braking force).
Time frame: Week 0, Week 6, Week 10
Changes in fat mass as assessed by dual energy x-ray absorptiometry (DXA) scans
Participants will be instructed to lie supine with hands by their sides on a GE Lunar iDXA machine for a full-body x-ray scan which will measure grams and percentage changed in fat mass.
Time frame: Week 0, Week 6, Week 10
Changes in fat-free lean mass as assessed by DXA scans
Participants will be instructed to lie supine with hands by their sides on a GE Lunar iDXA machine for a full-body x-ray scan which will measure grams and percentage changed in fat-free lean mass.
Time frame: Week 0, Week 6, Week 10
Changes in tolerance for physical pain and discomfort
Changes in preference for tolerance for physical pain and discomfort will be assessed by self-report questionnaire responses to the Discomfort Intolerance Scale (DIS). This scale measures individual differences in ability to tolerate uncomfortable sensations. There are 7 items total. Although there are two subscales (measure ability to tolerate discomfort / pain and avoidance of physical discomfort) only total scores will be used. There are 7 items total. Items are scored 0 - 6 (total range 0 - 42), with higher scores indicating greater ability to tolerate physical discomfort. Average score on the total scale will be used.
Time frame: Week 0, Week 6, Week 10
Changes in perceived support for physical activity from friends and family members
Changes perceived support for physical activity from friends and family members will be assessed by self-report questionnaire responses to the Social Support and Exercise Survey. This questionnaire measures 13 items are scored on a scale of 1 - 5, with higher scores indicating greater perceived support. Total scores will be used, with ranges from 13 - 65. Higher scores indicate greater perceived support. Average score for the total scale will be used. Items may be answered twice, once for family members and once for friends.
Time frame: Week 0, Week 6, Week 10
Changes in perceptions of how much exercise satisfies autonomy, relatedness, and competence needs
Changes in perceptions of how much exercise satisfies autonomy, relatedness, and competence needs will be assessed by self-report questionnaire responses to the Psychological Need Satisfaction in Exercise Scale. This scale measures how much the psychological needs of autonomy, relatedness, and competence are satisfied during exercise. There are three subscales: autonomy, relatedness, and competence. Each subscale has 6 items rated on a 6-point scale. Higher scores indicate greater amounts of the construct. Total subscale scores may range from 6 to 36. Subscale averages will be used in analyses.
Time frame: Week 0, Week 6, Week 10
Changes in intrinsic, external, interrogated, identified, introjected and amotivation for physical activity
Changes in intrinsic, external, interrogated, identified, introjected and amotivation for physical activity will be assessed by self-report questionnaire responses to the Behavioral Regulation in Exercise, 3rd Edition (BREQ-3).This scale measures how much exercise behavior is driven by intrinsic motivation, external motivation, interrogated motivation, identified motivation, introjected motivation, and amotivation (lack of motivation). There are 6 subscales with 4 items each: intrinsic, external, interrogated, identified, introjected, and amotivation. Items are measured on a 5-point scale, where higher scores indicated greater amounts of the construct. Subscale scores may range from 4 to 20. Average subscale scores will be used in analyses.
Time frame: Week 0, Week 6, Week 10
Changes in how enjoyable physical activity is perceived to be
Changes in how enjoyable physical activity is perceived to be will be assessed by self-report questionnaire responses to the Physical Activity Enjoyment scale (PACES). This scale measures how enjoyable or unenjoyable physical activity is perceived to be. The measure consists of 18 questions and no subscales. Each question is measured on a 7-point scale, where higher scores indicate greater enjoyment. Total scores may range from 18 to 126. Average score will be used.
Time frame: Week 0, Week 6, Week 10
Changes in perceived effort expended during exercise
Changes in perceived effort expended during exercise will be assessed by self-report questionnaire responses to the Borg Rating of Perceived Exertion Scale. This scale measures perceived physical exertion during exercise. There is only 1 item and no subscales. Scores may range from 0 to 10, with higher scores indicating greater perceived exertion. The total score will be used in analyses.
Time frame: Week 0, Week 6, Week 10
Changes in perceived pain/discomfort during exercise
Changes in perceived pain/discomfort during exercise will be assessed by self-report questionnaire responses to the Numeric Ratings Pain Scale. This single item scale measures muscle pain/discomfort associated with physical activity. There are no subscales. Scores may range from 0 to 11, with higher scores indicating greater pain/discomfort. The total score will be used in analyses.
Time frame: Week 0, Week 6, Week 10
Changes in perceived ability to continue exercise long-term
Changes in perceived ability to continue exercise long-term will be assessed by self-report questionnaire responses to the Barriers Self-Efficacy Scale (BARSE). This scale measures perceived ability to continue meeting exercise guidelines over the next 1 to 8 weeks. There are no subscales. 8 items are measured on an 11-point scale where higher scores indicate greater certainty in ability to complete exercise. Average score will be used in analyses.
Time frame: Week 0, Week 6, Week 10
Changes in perceived ability to stick to an exercise routine
Changes in perceived ability to stick to an exercise routine will be assessed by self-report questionnaire responses to the Exercise Confidence Survey. This scale measures perceived confidence in ability to make time for exercise and persist in an exercise routine. There are 2 subscales: sticking to it (8 items) and making time for exercise (4 items). Items are measured on a 5-point scale where higher scores indicate greater confidence. Total scores may range from 8-40 (sticking to it) or 4-20 (making time). Average subscale scores will be used in analyses.
Time frame: Week 0, Week 6, Week 10