Exercise as it relates to Disease/How aerobic activity affects anxiety sensitivity

The following information is a critique of Broman-Fulks, J. J., Berman, M. E., Rabian, B., & Webster, M. J. (2004). Effects of aerobic exercise on anxiety sensitivity.

What is the background to this research?
Anxiety sensitivity refers to the fear of anxiety and arousal-related sensations. In Australia, one in seven people are currently experiencing and anxiety disorder. Of the one in seven, more women experience anxiety than men.

There were various test completed by the participants to determine anxiety sensitivity. The Anxiety Sensitivity Index (ASI) used was a 16 item scale. The test contains 16 questions that specify different concerns that subject could have concerning their anxiety. The subjects answers each question by selecting one of five phases; each phase has a point attached to it: The higher the subjects score, the greater anxiety sensitivity.
 * Very little (0 points)
 * A little (1 point)
 * Some (2 points)
 * Much (3 points)
 * Very much (4 points)

The Body Sensations Questionnaire is compiled of 18 questions to determine which specific body sensations occur when the subject is put in a nervous or stressful situation. The subjects answer all of the questions using one of five phrases:
 * Not at all (1 point)
 * Somewhat (2 points)
 * Moderate (3 points)
 * Very (4 points)
 * Extremely (5 points)

The State-Trait Anxiety Inventory (STAI) is used to assess levels of state and trait anxiety. This is done through the subject answering 40 questions, 20 relating to state anxiety and 20 relating to trait anxiety. State anxiety refers to the emotional status that results from situational stress. Trait anxiety refers to how a person reacts in stressful situations.

Where is the research from?
The research was conducted by Joshua J. Broman-Faulks, Mitchell E. Berman, Brian A. Rabian and Michael J. Webster at the University of Southern Mississippi. The paper was then published in February 2004 in Faculty Publications by The Aquila Digital Community.

What kind of research was this?
The study is a randomized-control trial (RCT). A RCT aims to create a comparison of results between two or more different groups/treatments. It is important that participants in RCT’s are as similar as possible; for this trial they are of similar age, health status and ASI result. The participants are allocated a group at random to decrease bias in the results.

What did the research involve?
The purpose of the study is to examine different rates of physical activity and how it effects the participants mood. 54 participants were selected for the trial, 41 women and 13 men. Although there isn't an equal amount of men and women who participated in the study, it is more accurate of a general population as more women have reported to suffer from anxiety disorders than men. To be included in the study, participants must meet the specific criteria: Participants would be excluded if:
 * 1) Achieve a score of ≥25 on the ASI
 * 2) Be at least 18 years or age
 * 3) Be in good general health
 * 1) They have a health condition that would not allow for exercise to be completed
 * 2) They had current involvement in psychotherapy
 * 3) Are currently using psychotropic medication
 * 4) Have current involvement in an aerobic exercise program

Volunteers who were seen to meet the criteria were given the Physical Activity Readiness Questionnaire (PAR-Q) to determine if medical clearance was necessary before the commencement of exercise. The chosen participants were then randomly assignment to either a high-intensity (HI) aerobic exercise condition (n=29) or a low-intensity (LI) walking comparison condition (n=25). Participants completed a STAI, BSQ and ASI tests over three different sessions: before the first exercise session, after the five minute cool-down after the final session, and during the one week follow up.

The participants completed a total of 6x20 minute sessions over the span of two weeks, with 2-4 sessions completed per week. The warm-up for each session consisted of two minutes of stretching and two minutes on the treadmill. The HI exercise group were asked to walk or jog on the treadmill at a speed that will produce heart rates of 60-90% of their age predicted maximum heart rate. The participants were encouraged to increase their treadmill speed with each following session but were required to stay beneath 90% of maximum heart rate. Following the completion of the session, participants completed a five-minute active cool-down. The LI group followed the same protocol as the HI group however, their treadmill speed was set continuously at one-mile per hour. Participants heart rates were monitored during every session with the use of a heart rate monitor.

What were the basic results?
The researches hypothesised that both the HI exercise group and the LI exercise group would show improvements in anxiety sensitivity, however the HI group would have a greater improvement at the follow-up appointment.

What conclusions can we take from this research?
The results show that there is a positive relationship between exercise and anxiety sensitivity. The data shows that if the participants are able to exercise within 60-90% of their age-predicted maximum heart rate, there are better results when aiming to reduce anxiety sensitivity than when the participants are to keep their heart rate below 60% of their age-predicted maximum heart rate. This shows that both the HI exercise group and the LI exercise group a positive affect on anxiety sensitivity when compared to pre-treatment data, however the HI exercise group had a greater decrease in ASI results than the LI exercise group. This is what was predicted by the researches prior to the commencement of the trail.

The HI exercise group is the only group that showed significant reduction of fear of anxiety-related sensation, when comparing BSQ scores. The BSQ scores for the HI exercise group begins to decrease at the beginning of the second sessions. This shows that it was effective at rapid reduction of fear of anxiety-related sensations. There have been previous studies that have found aerobic exercise to reduce state anxiety (STAI scores). However, his study was unable to use aerobic exercise to reduce state anxiety. This could be due to participants not having been chosen based on high general anxiety scores. There is no evidence to suggest an association between ASI scores and STAI scores. However, there was evidence to suggest and association between ASI sores and BSQ scores.

Practical advice
The study found that 20 minutes of HI exercise was the most effective intensity of exercise to decrease anxiety sensitivity. However, it also showed that even 20 minutes of LI exercise had a positive effect on anxiety sensitivity. This could include simple activities such as walking to work, walking around during lunch, taking the dog for a walk 3 times per week to have a very positive impact on how people are feeling in their every day life.

Further information/resources
Beyond Blue

Full Research Article (Refer to Reference 1)

Black Dog Institute