How to Do a Tabata exercise to increase swimming stamina
Rest in between long bouts of exercise is recommended, since muscles need time to heal and patch themselves up after tearing (yes, any form of exercise makes micro tears in your muscles that must be healed. These tears are a good thing because once you get patched up, your muscles become stronger than before).
But rest periods within one workout are not recommended. Ongoing work tires you out quickly but that's the point. By keeping up your momentum you'll burn more fat and charge your metabolism.
Watch this video to learn how to do a no-break allowed Tabata exercise.