The COM-B Behaviour Change Model

What leads us to change our behaviour when it comes to fitness and exercise – or any other aspect of our lives? Is a desire to change enough on its own or do we need something more?

The COM-B Behaviour Change Model suggests that three key elements – capability, opportunity and motivation – have to be in balance for us to not only alter our behaviour but to maintain this over time.

What is the COM-B Behaviour Change Model?

The COM-B Behaviour Change Model was set out in a 2011 paper by Susan Michie, Maartje M van Stralen and Robert West, after they reviewed a number of other behaviour change models.

All three elements are required to work in perfect harmony for behavioural change to take place and to last. These elements are the hub of the Behaviour Change Wheel (BCW), which also has nine intervention functions that can be employed to address any deficits in the three elements, and seven policy categories that can allow these interventions to happen.

What are the three elements of the COM-B model?

A personal trainer or fitness instructor can help a client or potential client to change their behaviours by ensuring these three elements are in balance:

Capability – this represents an individual’s psychological and physical ability to change.

Opportunity – this covers outside influences on behavioural change, for example: time, resources, social opportunities and environmental factors.

Motivation – this is about the client’s internal drive, including any thoughts – conscious or subconscious – that encourage or discourage behavioural change.

How do these elements impact each other?

Capability, opportunity and motivation all work hand in hand when it comes changing behaviours.

A client might tell a fitness professional that their goal is to lose weight, increase muscle mass or improve their sporting performance. The trainer would then assess their fitness levels and recommend the best way of doing this.

If the personal trainer suggests attending the gym three times a week, the client would need to have the capability, opportunity and motivation to do this. So they would need to have the right mindset and physical capability, as well as the time to train, money for classes or 1-2-1 tuition, gym wear, ability to get to the gym (walk, bus, car), and finally, to be sufficiently motivated to make it to training three times a week.

What are the barriers to attending personal training sessions and achieving fitness goals?

Potential barriers and how they relate to other elements of the COM-B model include:

Example 1 – a client who is new to training is highly motivated and has just moved near a gym, so they have opportunity and motivation. Their personal trainer sets an intense workout and they don’t have the capability to complete it, which affects their motivation to continue.

Example 2 – an individual has the motivation to work towards weight loss goals and a new gym opens up nearby offering opportunity to train, but self-consciousness about their weight affects their psychological capability to attend fitness classes.

Example 3 – a client has the motivation and capability to train, but they don’t have a car and the nearest gym is too far to walk, hard to reach by public transport and not open at hours that suit their work shifts, reducing their opportunity to train.

Example 4 – a client has the opportunity to attend gym sessions, but an ongoing injury has reduced their physical capability to train or take classes; this affects their motivation.

Example 5 – an individual has the capability and opportunity to train but doesn’t have the motivation because they are stressed at work and they haven’t considered the benefits of exercise, such as increased energy levels and improved physical and mental health.

What other ways can a personal trainer promote behavioural change?

There are other systems that a personal trainer can use to promote behavioural change, for example:

Motivational Interviewing, where collaborative communication encourages the client to come to their own conclusions about why and how they need to change.

WOOP, where health and fitness goals are achieved by following the Wish Outcome Obstacle Plan strategy.

Clients – and fitness professionals – can also benefit from self-reflection and self-evaluation processes, where they look in more depth at how they think, feel and act, analyse the issues and take action to improve matters.