Research Review: How do you change your behavior?

By Helen Kollias


Many decisions are shaped by your belief that you have control over your own life and behavior… regardless of whether you ACTUALLY have control. So, are you the boss of you?

Why don’t we do what’s good for us?

We’ve all had those times when we were bad. And not the “I didn’t know so it’s not my fault” kinda bad, but the “fully aware, self-justified” kinda bad.

Why do we do things we…

  • Know are bad for us? For example, eating cheesy puffs.  (I personally deny having a cheesy puff problem. I only eat cheesy puffs socially… most of the time).
  • Really don’t want to do? Every time I eat cheesy puffs I realize that they don’t taste good. If fact they remind me of orange colored Styrofoam and yet on occasion I indulge – why?

Why don’t we do things we know we should do?

Not only do we do things we know we shouldn’t, we avoid things we know we should be doing. Exercise, for example.

I’d say everybody in the free world knows they should exercise (never mind the exact type) and I’m sure many really mean to (or intend) to exercise, but don’t.

Is it because it takes too much time? Maybe they don’t have the time, but there are way too many people watching reality TV to say there is a shortage of time for the average person.

So what’s the problem?

Can health care providers, personal trainers, concerned friends and family convince somebody to exercise?

What do you need to do to change your behavior?

Maybe we need a plan.

One theory, the “theory of planned behavior”, that says that intent (or purpose) is enough to change behavior (1). In this case, your intention is explicit, which then generates behaviorally oriented decisions. This means you have a set of goals that you intend to reach by acting a certain way. You plan to do something on purpose.

For example: you want to lose 10 pounds in the next two months by being 90% compliant to PN habits and exercising 5 hours a week.

You have a goal – check.

You have a plan – check.

You have all the intention you need.

So now you’re off to be successful! Right! Right?

While intention is really important, there is another piece to the theory of planned behavior: perceived behavioural control.

Are you in control of your behavior?

The first thing you need is the intent to exercise – with the goal and plan in place.

Then you need to think that you can control your behavior. Once you have your goal and your plan you need to BELIEVE that you can do it.

Psychologists have even put a number on how much “perceived behavior control” matters in intention: 45% of behavioral variance can be predicted by your belief that you have control.

Whether you actually have control doesn’t matter – assuming you’re not locked up 24 hours a day in a room so small you are actually unable to exercise. Whether you think you control your behavior is what matters.

So far you need:

  • A goal
  • A plan
  • The perception you control your behavior

With all this you must be exercising! Right! Right?

While this psychological model of theory of planned behavior does show that all these factors contribute to whether or not you will actually do the behavior (exercise for example) it’s not that good.

But what else could matter?

Research question

In a study by Chatzisarantis & Hagger (2) they found that intentions to participate in exercise (physical activity) didn’t always lead to exercise. This gap between what people intend to do and their behavior has been christened the “intention-behavior gap.”

In the study I review this week the researchers try to figure out other factors that could explain the gap between intent and behavior. They look specifically at how emotion may be the missing link in modifying behavior.

Mohiyeddini C, Pauli R. and Bauer S. The role of emotion in bridging the intention–behavior gap: The case of sports participation. Psychology of Sport & Exercise. 10 (2009): 226-234.


237 people completed the study – not a bad sample size for this type of study. They were on average just under 27 years old and a mix of men (108) and women (129).

What didn’t matter

Since gender and age weren’t covariates (as figured out by a statistical method called ANCOVA) they were excluded from the analysis.

Simplified translation: age and gender didn’t matter for attitude, intent, emotion or behavior, so researchers kept everybody as one big group.

Other stuff that didn’t seem to affect behavior:

  • Socioeconomic status – low versus high income
  • Exercise experience – whether or not they had past experience exercising (I thought this was a bit odd)

What did matter

Now we get into the interesting stuff. Pay attention. Here’s what made a difference in inspiring people to actually exercise.

Attitude toward exercise.

This was measured by having the participants pick one of two words to fill in the following blank – “Exercising twice a week is _______ for me.” Word pairs were: unpleasant or pleasant, boring or stimulating, unhealthy or healthy, bad or good and useless or useful.

Subjective norms

In other words, the way each participant’s close social network (i.e. family and good friends) felt about the participant’s exercise. This was measured by the participant answering three questions:

  • “People close to me think I should participate in regular physical activity” (agree/disagree)
  • “People who are important to me would…” (approve/disapprove – of my participating in regular physical activity.)
  • “People close to me think I…” should or should not – participate in regular physical activity

Perceived behavioral control.

This was measured by answering the following questions:

  • “To what extent do you see yourself as being capable of participating in regular physical activity?” (capable or incapable)
  • “How confident are you that you will be able to participate in regular physical activity?” (not very confident or very confident)
  • “I believe I have the ability to participate in regular physical activity.” (definitely do not – definitely do)
  • “How much personal control do you feel you have over participating in regular physical activity?” (no control or complete control)


This was measured 16 times the day before exercise was scheduled. The statements were rated on a six point scale by participants (-3 for “not at all true for me” to +3 “completely true for me”.

  • “My goal is to exercise tomorrow for at least 30 minutes.”
  • “I intend to exercise tomorrow for at least 30 minutes.”

Emotion (or emotional appraisal).

This was measured right after each measurement of intention – the day before exercise — by asking the participants to rate their feelings when thinking about their intention to exercise the next day.

The participants picked 4 of 24 adjectives (from the profile of mood states (3)) and rated them (on a six point scale) from 1 (not at all) to 6 (extremely).

Adjectives with the highest ratings were: Active, alert, energetic, lively, downhearted, unhappy, uncertain and worried.

Did they exercise?

Oh, this is pretty important — they also measured behaviour: how often (frequency) and how long (duration) people actually exercised.

The study lasted nine weeks. Recommended physical activity was to exercise twice a week for 30-60 minutes. This was based on the US Surgeon General, the American College of Sports Medicine and the Centers for Disease Control and Prevention.

Twice a week for 30-60 minutes! That’s it! Seems pretty small amount of exercise for anybody to get worked up over and pathetically little to be a recommendation by any self respecting group interested in health.

Whether or not this little exercise made a physical difference is irrelevant – what matters is that it was enough to be affected by the measures studied.


Sadly, twice a week for 30-60 min over 9 weeks was too much for many and only 70% of the sessions were completed. Ouch.

Only 32 minutes was the average over the sessions. Yup, most folks did the absolute minimum.

After analyzing the different measures it turned out that attitude, subjective norms and perceive behaviour control all impacted intention. Intention impacted how long and how often the participants exercised.

But there is more…. emotion matters. Emotion toward intent to exercise was directly correlated to how long and how much exercise the participants did. Emotion also impacted intention.

In other words, the way people felt about exercise, and their intent to exercise, affected whether they actually exercised.


The researcher’s hypothesis that emotions toward the intent to exercise mediate the intention-behaviour relationship was validated by exercise frequency and duration correlations.

In English, the researchers found that exercise was affected by:

  • how you feel toward your intention to exercise
  • your attitude toward exercise
  • your social network’s feelings about you exercising
  • your feelings of competency
  • your intent to exercise

Bottom line

What does this mean to you?

To give yourself the best chance in changing your lifestyle and exercising regularly you need to:

  • Intend to exercise – with a goal and plan in place.
  • Have a positive attitude toward the exercise you intend to do. Either find some form of exercise you enjoy, find a workout partner you want to work out with or change your attitude. If you hate it you will only do it for so long. You may find yourself enjoying the dull muscle ache a few hours after a hard workout.
  • Surround yourself with people who approve and believe that you should be exercising. Or avoid discussing the topic of exercise with people you know are unsupportive.
  • Believe that you are capable. Yes you can.
  • Have a positive attitude toward your intent to exercise. Believe in the goal and the plan.


Click here to view the information sources referenced in this article.

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