What is the 15 rule in swimming?
Meter rule: the swimmer stayed completely underwater for more than 15 meters off the start or turn. Re-submerged: after surfacing, the swimmer fully submerged again during the swim, which is not allowed. Here’s the truth: yes, swimming for 30 minutes can absolutely be enough exercise, especially if you’re consistent about it. At maru, we work with swimmers at every level, and we’ve seen firsthand how powerful a regular half-hour swim can be for building fitness, feeling stronger, and genuinely enjoying the process.