This is great, Catarina, and congratulations on all the great comments and feedback you've been receiving. My suggestions is to relentlessly focus on "change." What are the interventions that will lead to behavior change? Helping people already interested in healthy, active living is great, but I'd encourage you to dedicate as much time as possible to the "Julissas." She is a mother of two, and if you can achieve behavior change with her, that will ripple onto her kids' lives, and their kids, etc. And if, before your challenge activity, she's less likely to adopt a healthy lifestyle, that makes her an even more important priority audience. Bottom line, IMHO, is we need less preaching to the converted and more "conversion." Keep up the great work!