Introduction
mobility-related disability, mobility disability, pain
SECONDARY
Physical inactivity is one of the strongest predictors of mobility-related disability in older adults (The preservation of physical function in older adults is a major public health priority. It is therefore imperative that healthcare and exercise professionals acquire clear guidance to promote, refer, prescribe, and deliver evidence-based PA interventions to individuals at risk of mobility-related disability. Most current PA guidelines globally recommend engaging in some form of muscle strengthening activity at least twice per week but they lack specific guidance necessary for exercise prescription for older adults (Whilst successful, previous long-term exercise interventions for older adults at risk of mobility disability describe a lack of functional progression or training specificity to activities of daily living within their strengthening-based exercise programmes (The REtirement in ACTion (REACT) study represents the first large-scale (777 participants) pragmatic, trial in the United Kingdom to target the non-disabled but high-risk segment of the older population with an intervention to reduce mobility-related disability in a real-world community setting (For REACT, a multimodal exercise prescription using primarily callisthenics (exercises that use body weight to generate resistance) of varying functional difficulties was adopted using the “functional exercise continuum” (The REACT study progressive functional continuum.Choices and constraints: transitioning through the functional continuum as time and physical function progress. The choices and constraints model provides exercise leaders with a clear understanding of what type of exercises to prescribe during the supervised sessions during different phases of the overall REACT intervention. To optimise enjoyment and adherence during weeks 1 to 8 (start-up), the prescription of chair-based exercises will be permitted alongside standing with and without support (purple, orange and red blocks). During the first 8 week period, multidirectional and or explosive movements will not be permitted. The model reflects this “constraint” between weeks 1 to 8 by excluding the “multidirectional and or more explosive movement patterns” (blue block) from within the red dotted box. During weeks 9 to 12 (build-up) there are no “constraints” with regards to exercise prescription (depicted in the model by all types of exercise being included within the red dotted box). This does not mean that all participants should be doing explosive movements. Only those individuals who have proven during their supervised sessions to be functionally capable of progressing to these higher function tasks (able to perform many of the unsupported standing exercises independently) may start to perform these activities under the supervision of the exercise leader. From week 13 onwards (incorporating build-up and maintenance phases) constraints will be placed on chair based exercises (depicted in the model by its exclusion from within the red dotted box). This is to reinforce to the exercise leader that all eligible participants should be capable of performing exercises in a standing position (with support) following 3 months of supervised exercise provision. However, it is important to recognise that an element of common sense is required at all times when supervising exercise delivery of older adults at risk of mobility disability. If a participant feels fatigued or has joint pain during a specific task that can be alleviated by selecting a chair-based exercise, then using a chair should be encouraged. Additional information is provided in Theoretical model of exercise progression using component of the REACT Functional Continuum. The progression models presented here aim to simplify the reasoning process behind the prescription of exercises and may be applied to any given exercise prescribed within the local community settings. The model aims to help exercise leaders visualise the gradual progression of function or of any single exercise (Example of how the REACT progression model can be used to progress the development of REACT had a low attrition rate (19% at 24 months) and good intervention adherence (Whilst the SPPB composite score is useful as a global indicator of physical function, to facilitate future exercise guidelines for older adults it is important to evaluate how each individual component measure of the SPPB (balance, sit to stand and gait speed) responded to this successful 12 month intervention. Furthermore, understanding how each component of the SPPB responded to the REACT programme, alongside other secondary functional outcome measures, will provide greater clarity on the mechanisms underpinning the changes demonstrated in physical function. Such an evaluation will enable recommendations for future exercise programmes delivered in community settings for older adults at risk of mobility disability. Therefore, the aim of this study was to investigate the effectiveness of the REACT programme on the individual markers of lower-limb function as assessed by the three components of the SPPB and secondary outcomes of physical function at 6 months and 12 months follow-up (the supervised element of the REACT intervention) compared to controls.