This randomized cross-over study compares two identical cardiorespiratory exercise bouts, differing only in the inclusion or exclusion of a dynamic period of increasing exercise intensity prior to the exercise bout. Planned comparisons include physiological responses and perceived effort during exercise, leukocyte mobilization, and mood between the two exercise sessions.
Physically active adult men and women are asked to complete three study visits to the laboratory. On Visit 1, participants provide informed consent and are screened for study inclusion criteria: being between 18 and 40 years of age, a non-smoker, not pregnant, free of disease impacting exercise performance or immunity, and performing at least one hour per week of vigorous exercise training (any modality) for at least the prior six months. Participants also complete an incremental submaximal exercise test on a stationary bicycle. The results of this test are used to calculate the resistance corresponding to 80% of estimated maximal heart rate. Participants return within 2-14 days for Visits 2 and 3. These visits consist of 30 min of bicycling at this resistance. One visit included a 10 min dynamic warm-up prior to the exercise bout. Participants were stratified by sex and randomized such that half of the men and women completed the exercise trial with warm-up during Visit 2. Heart rate, perceived exertion, and wattage are recorded during each minute of the exercise bouts. Participants donate blood before, immediately after, and 1h after each exercise. Blood is analyzed by flow cytometry to characterize leukocyte subsets. After each exercise session, participants complete surveys assessing mood and affect. Physiological, immunological, and psychological parameters recorded will be compared within participants between the two experimental exercise sessions using appropriate statistical tests. p\<0.05 will be accepted as significant.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
24
30 minutes of exercise at 80% of maximum predicted heart rate performed on an indoor stationary bicycle. Exercise was preceded by 10 min of gradually increasing cycling intensity in one of two exercise trials
University of Houston
Houston, Texas, United States
Heart rate during exercise
Heart rate in beats per minute
Time frame: Minutes 1-30 of exercise, recordings made each minute
Perceived exertion during exercise
Rating of perceived exertion measured using the Borg 6-20 scale
Time frame: Minutes 1-30 of exercise, recordings made each minute
Power during exercise
Wattage produced on stationary bicycle
Time frame: Minutes 1-30 of exercise, recordings made each minute
Monocyte mobilization by exercise
Number of peripheral blood monocytes
Time frame: Change from resting levels of monocytes after exercise
Natural Killer cell mobilization by exercise
Number of peripheral blood natural killer cells
Time frame: Change from resting levels of natural killer cells after exercise
CD4 T cell mobilization by exercise
Number of peripheral blood CD4 T cells
Time frame: Change from resting levels of CD4 T cells after exercise
CD8 T cell mobilization by exercise
Number of peripheral blood CD8 T cells
Time frame: Change from resting levels of CD8 T cells after exercise
Mood after exercise
Mood dimensions characterized by Profile of Mood Survey
Time frame: Measured within 10 minute of end of exercise session
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Affect after exercise
Affect characterized by Positive and Negative Affect Schedule
Time frame: Measured within 10 minute of end of exercise session