4 – Tread Water For 15 Minutes
Treading water continuously for 15 minutes helps to measure your endurance. Treading waterworks almost all muscle groups, and helps to measure endurance. To tread water, get into a still pool (without currents, salt or distractions), and keep your head above water without floating, for 15 minutes. This should be an achievable task for most people and shows a good level of endurance.
