Exercise and habits

Exercise and habits

Gert-Jan de Bruijn

Amsterdam School of Communication ResearchUniversity of Amsterdam

Habits

Behaviour you have done repeatedly in stable context

Some researchers provide evidence that habits are goal-actived behaviours

“We are what we repeatedly do” - Aristotle (384 - 322 BC)

“Most of the time, we do things we do most of the times”

‘A matter of routine, I’ve done it ever since I finished school” - ABBA (The day before you came)

Overview

Understanding exercise behaviour and habits: action control research

Understanding exercise behaviour and habits: affective considerations of exercise

Modeling exercise automaticity: two longitudinal studies in undergraduate samples

Habits and Exercise Action Control

Action control: translating intentions into behaviour (e.g. Kuhl, 1985, 1992)

Typically, 30%-50% of study samples are not translating their intentions into behaviour

Is this ‘gap’ less pronounced when strong habits have developed?

Apparently so....

Some work with Ryan Rhodes, University of Victoria


Weak habitWeak habit Insufficient PA Sufficient PA

Nonintender 25 3

Intender 6 2

Moderate habitModerate habit

Nonintender 19 6

Intender 13 25

Strong habitStrong habit

Nonintender 7 2

Intender 7 28

Rhodes, Matheson, De Bruijn (2010) J Sport Exerc Psychol, 32, 84-98



Nonintender 89.3% 10.7%

Intender 75% 25%


Nonintender 76% 24%

Intender 34.2% 65.8%



Intender 20% 80%





Intender 75% 25%


Nonintender 76% 24%




Intender 20% 80%




Nonintender 147 2

Intender 34 10


Nonintender 18 0

Intender 70 49

De Bruijn (2011). Psychol Sport Exerc, 12, 106-114






Nonintender 100% 0%








Nonintender 100% 0%



Stronger exercise habits minimize the intention-exercise gap

The relationship is still not perfect, even when strong exercise habits exist

Interact the interaction?

Self-regulatory planning strategies have helped before (some work by someone called Falko)

Intermezzo I

Methods

Online study amongst undergraduate students in a social psychology course (n=415)

Baseline assessment: intention - habit strength - action planning

Follow-up (= baseline + two weeks): exercise behaviour (IPAQ)

Baseline items in relation to ‘exercising for at least 60 minutes in the next two weeks’ on 7-point scales (-3 = totally disagree; +3 = totally agree)

Action planning items (alpha = .94)

I have made detailed plans (i) when, (ii), where, (iii) with whom, and (iv) what kind

Intention items (alpha = .96)

(i) I intend to exercise and (ii) I am sure I will exercise

Habit strength items cf. Verplanken and Orbell (2003): alpha = .95e.g. exercising is something (i) I do automatically, (ii) I start doing without having to think aboutit, (iii) I do without thinking, (iv) I would find hard not do

Methods

Analytical plan

Basic descriptives

Stepwise regression analysis

Step 1: Perceived Behavioural Control - Intention

Step 2: Instrumental Attitude - Affective Attitude - Subjective Norms

Step 3: Habit Strength - Planning

Step 4: The three two-way interactions (e.g. planning x intention, habit x planning)

Step 5: Three-way interaction habit x planning x intention

Follow-up analysis

Two-way interaction: slope analysis using Aiken & West (1991) suggestions

Three-way interaction: slope analysis and slope comparison tests using Dawson & Richter (2006) suggestions

Step 1 Step 2 Step 3 Step 4 Step 5

Intention .24** .24** .18* .18* .17*

PBC .34*** .33*** .25** .19* .22**

Step 2 variables

Instrumental attitude .04 .04 .01 .01

Affective attitude .02 -.08 .01 -.01

Subjective norm -.05 -.08 -.06 -.05

Step 3 variables

Habit strength .23** .15* .10

Planning .20** .25** .14*

Step 4 variables

Habit x Planning .13 .14

Habit x Intention .22** .24***

Intention x Planning .20** .25***

Step 5 variables

Habit x Planning x Intention .15**

Results (2)

De Bruijn, Rhodes, & Van Osch (in press). J Behav Med

Simple slope analysis

Planning x intention interaction

Low exercise planning: intention - exercise beta = .27***

Medium exercise planning: intention - exercise beta = .43***

High exercise planning: intention - exercise beta = .63***

Habit x intention interaction

Low exercise habit: intention - exercise beta = .16*

Medium exercise habit: intention - exercise beta = .42***

High exercise habit: intention - exercise beta = .62***

Simple slope analysis: planning x habit x intention

Low Intention High Intention

Exer

cise

beh

avio

ur

(1) High Planning, High Habit

(2) High Planning, Low Habit

(3) Low Planning, High Habit

(4) Low Planning, Low Habit

Low planning, low habit: Intention-exercise beta = -.08 (ns)

High planning, low habit: Intention-exercise beta = .17 (ns)

Low planning, high habit: Intention-exercise beta = .25*

High planning, high habit: Intention-exercise beta = .74***


Planning x habit x intention: follow-up tests of slope differences

High planning, high habit (beta = .74)

High planning, low habit (beta=.17): t(413) = 5.204***

Low planning, high habit (beta=.25): t(413) = 4.318***

Low planning, low habit (beta=-.08): t(413) = 5.794***

High planning, low habit (beta = .17)

Low planning, high habit (beta=.25): t(413) = .-.428 (ns)

Low planning, low habit (beta= -.08): t(413) = 2.593**

Low planning, high habit (beta = .25)

Low planning, low habit (beta=-.08): t(413) = 3.754***


Strong exercise habits minimize the intention-exercise gap

Strong habits in combination with strong action plans minimize this gap even further

Intermezzo II

One potential problem: we tend to ask people all sort of things before they exercise

How to people think about exercise, after they have done their exercise?

Study on Habits, Exercise, Pre-exercise affect, and Post-exercise affective responses

Why study affective responses?

Judgments about the overall pleasure/enjoyability of exercise behaviour

Meta-analysed r between PA and affect is .42 (95%CI .37-.46) (Rhodes et al., 2009)

Affect and Exercise

Affect influences exercise behaviour directly (e.g. unmediated by intentions), similar to habit

Usually a strong correlation between affective attitudes and habits (r between .40 and .66)

Main question: how do strong habitual exercisers react to insufficient exercise?

Study done in collaboration with Professor Bob Grove (University of Western Australia)

288 participants (M = 21.3 years, SD = 2.96, 73.3% females)

Baseline data (-3=totally disagree; +3 = totally agree)

Affect and Exercise

SRHI towards sufficient exercise behaviour

Affective attitude towards sufficient exercise behaviour in the next 2 weeks

Enjoyable - Pleasant - Relaxing

I intend to / I am sure I will engage in sufficient exercise in the next 2 weeks

Follow-up data (= baseline + 2 weeks)

Exercise behaviour in the previous two weeks (relevant items from IPAQ)

Post-exercise affective attitudes (enjoyable - pleasant - relaxing)

Engaging in the amount of exercise in the past two weeks, was for me...

Three exercise habit strength groups

Weak habits: habit strength score <= -2 (n = 53)

Affect and Exercise: Methods

Moderate habits: habit strength score between -2 and +2 (n = 197)

Strong habits: habit strength score >= +2 (n = 38)

Two exercise groups

Insufficient exercise: did not meet the exercise norm (n = 227)

Sufficient exercise: did meet the exercise norm (n = 61)

2 (norm) x 3 (habit strenght) analysis of variance, with intention as covariate

Affect and Exercise: Results

-1

0

1

2

3

Post-Exercise Affect

2,59

1,61

0,21

Low Habit Moderate Habit Strong Habit

F(2,282) = 35.55, p < .001, η2 = .20


-1

0

1

2

3

Pre-Exercise Affect

2,16

1,51

Insufficient Exercise Sufficient Exercise

F(2,283) = 3.96, p = .0122, η2 = .02


-1

0

1

2

3

Pre-Exercise Affect

2,75

1,9

2,42

1,53

0,21

Low Habit Moderate Habit Strong Habit Moderate Habit Strong Habit

F(1, 283) = 0.01, p = .942, η2 = .00

Do not meet norm Meet norm

Affect and Exercise: Pre-exercise Affect

Not particularly novel

People who have a more enjoyable outlook on future exercise behaviour...

...exercise more.

This effect does not depend on exercise habit strength

Perhaps somewhat novel

What happens with post-exercise affect?


-1

0

1

2

3


2,86

1,521,51

1,11

-0,03


F(1, 283) = 6.45, p = .016, η2 = . 03



-1

0

1

2

3


1,52

1,11


Mean difference = 0.41, p = .354



-1

0

1

2

3


2,86

1,51

Low Habit Moderate Habit Strong HabitModerate Habit Strong Habit

Mean difference = 1.35, p < .001


Affect and Exercise: Post-exercise Affect

People who do not exercise in line with their habits, feel bad about their performance

This effect is most pronounced in those who have strong exercise habits

Use anticipated regret in exercise interventions?

Intermezzo III

Strong exercise habits minimize the intention-exercise gap

Strong habits in combination with strong action plans minimize this gap even further

People with strong habits have strong (negative) affective responses to insufficient exercise

Perhaps we can conclude that exercise habits are relevant for exercise behaviour

Then what predicts exercise habits? Two studies on exercise automaticity

Undergraduate students (66.6% female, mean age = 21.24 (SD = 2.82)

Antecedents of exercise automaticity (study 1)

Baseline data

Intention towards sufficient exercise behaviour in the next two weeks

Perceived Behavioural Control towards sufficient exercise behaviour

Affective and Cognitive attitude towards sufficient exercise behaviour

Planning items when - where- what type of exercise behaviour

Follow-up data (baseline + 2 weeks)

Habit strength towards exercise behaviour

Stepwise regression analyses: follow-up habits as dependent variable

Step 1: main effects

Step 2: interaction effects

Step 1: significant T0 predictors of T1 exercise automaticity

Affective attitude: B = .14

PBC: B = .43

Planning when: B = .18

Planning where: B = .18

Exercise behaviour: B = .22

Step 2: significant T0 interactions of T1 exercise automaticity

PBC * Planning when: B=.24



Simple Slope analyses

Low PBC: Planning When - Automaticity relationship is B = .20, p = .001

Mean PBC: Planning When - Automaticity relationship is B = .11, p = .012

High PBC: Planning When - Automaticity relationship is B = .06, p = .274

What predicts increases in exercise automaticity?

When you have low self-efficacy, you need to plan when

When you have high self-efficacy, you do not need to plan when

You should exercise more

You should enjoy it more

You should feel confident about exercising

You should plan when and where to exercise


Three wave study in undergraduate students (n = 288)

Time 0: intention - action planning - habit - exercise behaviour


Time 1: intention - action planning - habit - exercise behaviour

Time 2: habit - exercise behaviour

Structural Equation Models were constructed in AMOS 7.0

Test significance of all paths

Test mediation of T1 variables on T0 - T2 relationships

Exercise Intention Habit Planning


Exercise Habit

Model fit: χ = 46.86 (9), p < .001, NFI=.98, CFI=.98, RMSEA=.09, AIC=158.86



Exercise Habit

Final model fit: χ = 19.45 (15), p = .149, NFI=1.00, CFI=1.00, RMSEA=.02, AIC=119.46

Exercise T0 predicts exercise T1 (b=.60), intention t1 (b=.14) and habit T1 (b=.19)

Intention T0 predicts intention 1 (b=.49)

Planning T0 predicts Planning T1 (b=.62), exercise T1 (b=.15), and intention T1 (b=.11)

Habit T0 predicts Planning T1 (b=.19), exercise T1 (b=.15), Habit T1 (b=.58), intention T1 (b=.19)

Habit T0 also predicts Habit T2 (b=.45)

Exercise T1 predicts exercise T2 (b=.66)

Habit T1 predicts Habit T2 (b=.45) and Exercise T2 (b=.10)

Intention T1 predicts Habit T2 (b=.16) and Exercise T2 (b=.11)


Relevant references

De Bruijn GJ, Rhodes Re, Van Osch L (in press). Does action planning moderate the intention-habit interaction int the exercise domain? A three-way interaction analysis investigation. J Behav Med

Gardner B, De Bruijn GJ, Lally P (2011). A systematic review and meta-analysis of applications of the self-report habit index to nutrition and physical activity behaviors. Ann Behav Med, 42, 174-187.

De Bruijn GJ (2011). Exercise habit strength, planning and the theory of planned behaviour: an action control approach. Psychol Sport Exerc, 12, 106-14

Rhodes RE, De Bruijn GJ, Matheson D (2010). Habit in the physical activity domain: Integration with intention temporal stability and action control. J Sport Exerc Psychol, 32, 84-98

De Bruijn GJ, Keer M, Conner M, Rhodes, RE (in press). Using implicit associations to understand fruit consumption behaviour and habit strength relationship. J Health Psychol

Education

Exercise and habits