Effects of a Warm-up on Immune Response to Exercise

Overview

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.

Full Title of Study: “The Effects of a Dynamic Warm up on the Immune Response to Exercise in Lower Fit and Higher Fit Adults”

Study Type

• Study Type: Interventional
• Study Design
  • Allocation: Randomized
  • Intervention Model: Crossover Assignment
  • Primary Purpose: Basic Science
  • Masking: None (Open Label)
• Study Primary Completion Date: February 1, 2020

Detailed Description

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.

Interventions

• Behavioral: Exercise
  • 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

Arms, Groups and Cohorts

• Experimental: Warm-up, then no warm-up
  • Participants’ visit 2 included 10 minutes of gradually increasing intensity prior to the 30 minute exercise session. Participants’ visit 3 consisted of the 30 minute exercise session without a warm-up.
• Experimental: No warm-up, then warm-up
  • Participants’ visit 2 consisted of the 30 minute exercise session without a warm-up. Participants’ visit 3 included 10 minutes of gradually increasing intensity prior to the 30 minute exercise session.

Clinical Trial Outcome Measures

Primary Measures

• Heart rate during exercise
  • Time Frame: Minutes 1-30 of exercise, recordings made each minute
  • Heart rate in beats per minute
• Perceived exertion during exercise
  • Time Frame: Minutes 1-30 of exercise, recordings made each minute
  • Rating of perceived exertion measured using the Borg 6-20 scale
• Power during exercise
  • Time Frame: Minutes 1-30 of exercise, recordings made each minute
  • Wattage produced on stationary bicycle
• Monocyte mobilization by exercise
  • Time Frame: Change from resting levels of monocytes after exercise
  • Number of peripheral blood monocytes
• Natural Killer cell mobilization by exercise
  • Time Frame: Change from resting levels of natural killer cells after exercise
  • Number of peripheral blood natural killer cells
• CD4 T cell mobilization by exercise
  • Time Frame: Change from resting levels of CD4 T cells after exercise
  • Number of peripheral blood CD4 T cells
• CD8 T cell mobilization by exercise
  • Time Frame: Change from resting levels of CD8 T cells after exercise
  • Number of peripheral blood CD8 T cells

Secondary Measures

• Mood after exercise
  • Time Frame: Measured within 10 minute of end of exercise session
  • Mood dimensions characterized by Profile of Mood Survey
• Affect after exercise
  • Time Frame: Measured within 10 minute of end of exercise session
  • Affect characterized by Positive and Negative Affect Schedule

Participating in This Clinical Trial

Inclusion Criteria

• identifies as exercising 1-3 hours per week or more than 6 hours per week, on average (last 6 months) – meets American College of Sports Medicine criteria for participation in exercise Exclusion Criteria:

• underlying medical problems that contraindicate supervised high intensity exercise – past or present history of autoimmune disease, HIV, hepatitis, stroke, or cardiovascular disease – chronic/debilitating arthritis – central or peripheral nervous disorders – asthma, emphysema, or bronchitis – bedridden in the past three months – history of blood clotting disorders – administration of any medication that might affect physiological response to exercise – functional or cognitive impairment that would limit exercise performance or prohibit informed consent – having any common-cold or influenza like symptoms (scratchy throat, runny nose, inflamed sinuses, frequent sneezing or coughing) in the last 2 weeks – pregnancy – tobacco use

Gender Eligibility: All

Minimum Age: 18 Years

Maximum Age: 40 Years

Are Healthy Volunteers Accepted: Accepts Healthy Volunteers

Investigator Details

• Lead Sponsor
  • University of Houston
• Provider of Information About this Clinical Study
  • Principal Investigator: Emily C Lavoy, Assistant Profesor – University of Houston
• Overall Official(s)
  • Emily C LaVoy, PhD, Principal Investigator, University of Houston