'Brief advice' means verbal advice, discussion, negotiation or encouragement, with or without written or other support or follow-up. It can vary from basic advice to a more extended, individually focused discussion (see NICE public health guidance 44).
'Inactive' is defined as not currently meeting the Chief Medical Officer's recommendation for physical activity as outlined in Start active, stay active: a report on physical activity from the four home countries' Chief Medical Officers (Department of Health 2011).
Level 4 refers to the National Occupational Standards levels for exercise instructors. These are currently being reviewed. See The Register of Exercise Professionals for details.
Phase 3 refers to the rehabilitation phase of a disease care pathway. This generally takes place after hospital discharge. It consists of structured exercise training, education and psychological support and advice on risk factors. Phase 4 refers to long term maintenance of physical activity following completion of Phase 3. It consists of exercise classes in leisure centres and community settings.
People benefit psychologically from physical activity. This short-term 'feel good' factor is referred to in economic terms as 'process utility'.
Being sedentary is not just a lack of physical activity (see 'inactive'). Sedentary behaviour involves activities that do not increase energy expenditure much above resting levels, for example, sitting, lying down, sleeping, watching TV and reading. Sedentary behaviour is an independent risk factor for chronic disease. People who achieve the recommended levels of physical activity can still be at risk if they spend too long being sedentary. (Evidence briefing: sedentary behaviours British Heart Foundation National Centre for Physical Activity and Health 2012).