Marcus Delacroix

Group challenges work best when they measure collective progress, not individual performance.

Sync your workout times to your body's peak hours, not your partner's schedule.

Automaticity, not willpower, sustains solo workouts—here's how to build it.

Family fitness challenges work when they fold parents' exercise into time already spent with kids.

Research shows couples who exercise together stay committed far longer than solo exercisers.

Couples who exercise together stick with it—here's which apps actually support that dynamic.

Written agreements turn vague fitness promises into measurable commitments with real consequences.

When one partner goes quiet, the structure breaks unless the app anticipates it.

Research shows scheduled check-ins with another person boost follow-through from 35% to 95%.

Couples who exercise together stay committed at nearly double the rate of solo exercisers.