Logging is the active ingredient.
A 2011 systematic review of 22 weight-loss studies found a consistent association between self-monitoring and weight-loss success, while also noting weak evidence quality and adherence decay over time.2
The research behind Core
Why we built it this way.
Core is built around a small set of findings that keep showing up in fitness-app and behavior-change research: short focused windows matter, self-monitoring matters, and the app has to stay useful after the first burst of motivation fades.
Axo evidence check
Claims need receipts. The sources are below.
What the evidence says
Fitness apps can help, but only if people keep using them.
The useful app is not the app with the longest feature list. It is the app people return to when the novelty is gone and the work still has to happen.
Apps work best when the window is focused.
A 2019 meta-analysis of 9 randomized controlled trials found modest overall support for smartphone apps increasing physical activity, with stronger effects in interventions under three months.1
The useful app has to stay engaging.
The 2025 BMC qualitative study you flagged found self-monitoring was the most frequent reason people used fitness apps, cited by 79% of respondents. Users also valued historical records that helped them surpass their own prior performance.3
Group competition is not free.
The same 2025 study found mixed responses to gaming and social comparison: motivating for some, demotivating or risky for others. Core is built around your own history first, not a public scoreboard.3
Feedback keeps the work from going silent.
The research base repeatedly points to feedback, self-monitoring, and perceived usefulness as important engagement drivers. That is why Core can turn a week into a professional-ready brief when the user chooses to share one.1,2
The underlying problem is large.
WHO reported in June 2024 that 31% of adults and 80% of adolescents do not meet recommended physical activity levels, and that insufficiently active people have a 20-30% higher risk of death than sufficiently active people.WHO
Axo in the lab
Research only matters when it changes the build.
Axo looks for the parts that should shape Core: what people keep using, where motivation breaks, and how to turn the record into a next move without pretending a study proves more than it does.
What Core is doing about it
Core answers with a short challenge, fast logging, and controlled sharing.
Start with a focused window.
The Baseline is short because engagement is fragile. Finish the window, learn the pattern, then decide the next one.
Make self-monitoring fast enough to repeat.
The app earns its place by making the record easy enough to keep: meal, fast, lift, sleep, Watch signal.
Add accountability without surrendering control.
Bring in a professional when it helps. They see the categories you share. Nothing else.
Measure retention before making outcome claims.
Core is not claiming results it has not earned. The first job is to learn which features people actually keep using.
Bibliography
Sources cited on this site.
1. Romeo et al. 2019
Romeo A, Edney S, Plotnikoff R, Curtis R, Ryan J, Sanders I, Crozier A, Maher C. “Can Smartphone Apps Increase Physical Activity? Systematic Review and Meta-Analysis.” Journal of Medical Internet Research 2019;21(3):e12053.
Read the study2. Burke, Wang, Sevick 2011
Burke LE, Wang J, Sevick MA. “Self-monitoring in weight loss: a systematic review of the literature.” Journal of the American Dietetic Association 2011;111(1):92-102.
Read the study3. Sousa Basto & Ferreira 2025
Sousa Basto P, Ferreira P. “Mobile applications, physical activity, and health promotion.” BMC Health Services Research 2025;25:359. This is the open-access PMC paper Scott flagged for app engagement and self-monitoring context.
Read the studyWHO. Physical activity fact sheet
World Health Organization. “Physical activity.” Fact sheet, 26 June 2024. Used for global physical inactivity and risk context.
Read the fact sheetResearch limits
What we will not overclaim.
Nothing here is a treatment claim. Core is not a medical device. The research cited on this page is about fitness apps, physical activity, and self-monitoring in general, not proof that Core itself produces outcomes.