Data analysis
Analyses were conducted using SPSS version 26 with a significance level of 0.05. One-way Analysis of Variances (ANOVA) were conducted to compare intervention groups on each continuous engagement (usage) measure. A Generalised linear model with a multinominal distribution and cumulative logit link was conducted to compare intervention groups on number of action plans completed (0, 1, or 2). Chi-square tests were used to compare intervention groups (tailoring + Fitbit and tailoring only) on the percentage of participants that perceived 1) the whole program, 2) the action planning tool, and 3) the library of exercises as useful. Chi-square analyses were conducted to compare intervention groups on the percentage of participants agreeing to each individual question on advice acceptability. A one-way ANOVA was conducted to compare intervention groups on the total advice acceptability score. Chi-square analyses were conducted to compare the intervention groups on the percentage of participants agreeing to each individual question on the SUS scale. A one-way ANOVA was conducted to compare intervention groups on the total SUS score. Content analysis was used to analyse the qualitative data responses to the opened ended questions on the 