Transtheoretical Model

The  Transtheoretical  Model  of  Behavior  Change (TTM)   was   originally   developed   by   James O. Prochaska and Carlo C. DiClemente for understanding  the  stages  and  processes  of  smoking cessation  and  over  the  past  3  decades  has  been broadly applied for understanding change across a variety of behaviors, including exercise and physical  activity.  The  TTM  was  developed  to  be  comprehensive model of behavior change by including cognitive,  behavioral,  and  temporal  components into a single framework for behavior change. The five  components  within  the  TTM  are  stages  of change, processes of change, self-efficacy, decision balance, and temptation. Stages of change classify one’s preparedness and progress toward behavior change, and progress is directed by the other four TTM  components.  Indeed,  processes  of  change, self-efficacy, decision balance, and temptation differ in level and importance among stages, and can be  guiding  pillars  of  interventions  for  promoting progression and preventing regression of individualized behavior change.

The stages of change characterize the preparedness  or  readiness  dimension  into  five  progressive stages  or  timelines  along  which  behavior  change occurs.  The  first  stage  is  precontemplation  and includes  persons  with  no  intention  of  change within  the  next  6-month  period.  Essentially,  the person  has  not  even  considered  behavior  change. The  second  stage  is  contemplation  wherein  the person  has  considered  behavior  change  within the  next  6-month  period.  Essentially,  the  person has  begun  thinking  about  a  change  in  behavior.

The  third  stage,  preparation,  describes  a  person who  possesses  immediate  intentions,  plans,  and commitment  for  changing  behavior  (e.g.,  within next month) but has not done so yet. This is followed  by  the  action  stage  wherein  persons  have initiated behavior change, but this change has been sustained for less than a 6-month period. The last stage  is  maintenance,  wherein  behavior  change has occurred and been maintained for a prolonged period, for example, longer than 6 months. When considering behavior change, the goal is for individual progression from precontemplation through action  stages,  and,  once  action  and  maintenance are  reached,  prevention  of  relapse  into  an  early stage.  Importantly,  persons  can  change  by  single stages  or  multiple  stages  (e.g.,  precontemplation →  preparation).  Such  change  occurs  through  the consideration  and  focus  on  the  other  four  TTM components.

Processes of change have been categorized into broad groups of experiential or behavioral factors and represent the strategies adopted and targeted for  stage  progression  or  prevention  of  relapse when   in   action   or   maintenance.   Experiential processes such as consciousness raising, like seeking  new  information  about  a  problem  behavior, and  self-reevaluation,  like  appraising  one’s  values  regarding  a  problem  behavior,  are  gathered through personal experiences, whereas behavioral processes,  such  as  stimulus  control  in  controlling  situations  that  trigger  a  problem  behavior, and  reinforcement  management,  like  rewarding one’s  self  for  changing  a  problem  behavior,  are developed  through  interactions  with  the  environment  or  through  action.  Experiential  processes are  seemingly  more  important  for  progression  in earlier  stages,  whereas  behavioral  processes  have greater  importance  during  later  stages  of  change. The  processes  further  are  amenable  for  target  by professionals  and  researchers  for  promotion  of individualized behavior change.

Self-efficacy  reflects  one’s  personal  confidence or  agency  in  successfully  executing  a  course  of action,  or  within  the  context  of  TTM,  changing one’s  behavior  and  progressing  through  stages. Self-efficacy  seemingly  increases  with  stage  progression.  Whereas  the  TTM  does  not  explicitly identify  targets  for  changing  one’s  self-efficacy, Albert Bandura has outlined performance accomplishment, vicarious experience (social modeling), verbal persuasion (social support), and physiological  or  affective  states  as  variables  for  changing self-efficacy expectations. This permits self-efficacy to  be  a  constructive  target  by  professionals  and researchers for promotion of individualized behavior change.

The last two components of the TTM are decision  balance  and  temptations.  Decision  balance reflects a person’s beliefs and evaluation of the pros (benefits) and cons (costs) of engaging in a behavior, whereas temptation reflects negative urges toward withdrawing  from  a  behavior  change.  Stage  progression  occurs  as  pros  outweigh  cons  (benefits  > drawbacks) and when temptations are minimized.

Collectively, individuals progress through stages of change by adopting experiential processes early (e.g.,  consciousness  raising  for  moving  from  precontemplation  →  contemplation  →  preparation), and  behavioral  processes  later  (e.g.,  stimulus control  for  moving  from  preparation  →  action →  maintenance).  Self-efficacy  is  lowest  with  the early stages (e.g., precontemplation) and increases across  stages  (e.g.,  preparation  →  action)  until  it peaks  with  maintenance.  Regarding  decision  balance,  cons  outweigh  pros  during  early  stages  of precontemplation,  contemplation,  and  preparation, for instance, and pros outweigh cons during later  stages  like  action  and  maintenance.  Finally, temptations  are  highest  within  the  early  stages (e.g., precontemplation) and decrease across stages (e.g.,  preparation  →  action)  until  its  nadir  with maintenance.

The  TTM  is  appealing  because  it  categorizes persons  based  on  readiness  for  change  and  then provides  concrete  strategies  and  approaches  for changing a health behavior. This has great appeal for  highly  individualized  behavior  change.  The theoretical  mechanisms  for  behavioral  change included   in   the   TTM   are   further   applicable among  diverse  behaviors  and  populations.  This has  great  appeal  for  adopting  the  TTM  across multiple behaviors and person domains. An additional  benefit  is  that  the  TTM  is  application  for multiple-behavior change within a single program, and the appeal is that the effectiveness of multiple changes  can  be  maximized  within  an  individualized intervention.

The  TTM  is  particularly  appealing  for  applications  involving  change  in  physical  activity  and exercise behavior; this has been nicely described by Claudio  Nigg  and  Simon  Marshall.  Importantly, exercise  behavior  can  readily  be  considered  as  a dichotomous change process—that is engaging or not  engaging  in  a  prescribed  exercise  routine  for a  considerable  time.  The  application  for  physical activity  has  been  more  difficult  as  this  is  often considered a continuous behavior, unless we apply the TTM for meeting public health guidelines for physical  activity  of  150  minutes  of  moderate-to vigorous physical activity per week. This is critical considering concerns directed toward applications of the TTM for understanding change in continuous  variables  such  as  physical  activity  behavior. Nevertheless,  the  TTM  has  major  strengths  in its  potential  for  tailored  applications  regarding  a person’s  readiness  for  change  in  physical  activity or  exercise,  particularly  given  the  public  health crisis  of  inactivity  and  sedentariness.  This  makes the  TTM  amenable  for  research-based  interventions  and  practitioner-led  applications  involving individual change in these behaviors. For example, there may be big differences among people regarding their readiness for undertaking an exercise program: some may only be thinking about beginning a  program,  whereas  others  might  be  considering strategies for maintaining a morning exercise routine.  Both  groups  of  persons  have  the  same  goal of  exercise  or  physical  activity  but  require  different information and processes, thereby necessitating  different  interventional  or  practitioner-based approaches. Indeed, the TTM is simple and clear enough  that  it  can  be  adopted  by  any  researchers or practitioners, such as nurses, social workers, psychologists, or physiotherapists.

There have been contentious issues when applying  the  TTM  to  physical  activity  and  exercise behavior  change,  perhaps  most  importantly  that the  TTM  was  originally  developed  for  cessation of a behavior (smoking with addictive properties), whereas  its  application  for  exercise  and  physical activity involves starting or adopting a new behavior  with  minimal  addictive  properties.  Of  further note, smoking is not performed with great energy expenditure above resting levels, whereas physical activity  and  exercise  by  definition  must  be  performed with a substantial increase in energy expenditure. There are further conflicting intentions and goals between smoking cessation and starting physical activity behavior. These points must be considered for balancing enthusiasm toward applications of the TTM in physical activity and exercise applications and should encourage careful thought and consideration when it is applied within the promotion of this health behavior change.


  1. Bandura, A. (1977). Self-efficacy: Toward a unifying theory of behavior change. Psychological Review, 84, 191–215.
  2. Marshall, S. J., & Biddle, S. J. (2001). The transtheoretical model of behavior change: A meta-analysis of applications to physical activity and exercise. Annals of Behavioral Medicine, 23, 229–246.
  3. Nigg, C. R., Geller, K. S., Motl, R. W., Horwath, C. C., Wertin, K. K., & Dishman, R. K. (2011). A research agenda to examine the efficacy and relevance of the transtheoretical model for physical activity behavior. Psychology of Sport and Exercise, 12, 7–12.
  4. Prochaska, J. O., & DiClemente, C. C. (1983). Stages and processes of self-change of smoking: Toward an integrative model of change. Journal of Consulting and Clinical Psychology, 51, 390–395.
  5. Weinstein, N. D., Rothman, A. J., & Sutton, S. R. (1998). Stage theories of health behavior: Conceptual and methodological issues. Health Psychology, 17,290–299.

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