Do Sprints Once a Week.
Just like in running, doing sprints in the pool can save you from needing to do massively long workouts in the pool. Once a week is enough. Think about combining middle distance swims (like 200s or 400s) with sprint 25s or 50s. An example would be 8x200 at a moderate pace with a 50 in between each one. The 50 is done as 25 sprint/25 easy. That can be the bulk of your workout for the day.
Strategically Use Fins
I have no love for "toys" when it comes to swimming! I prefer minimalism. But fins can help you accelerate your progress with drills. With most drills, you will start to "get it" much faster if you wear a pair of fins when you do them. Make sure they are the shorter-style fins, like Zoomers. Also resist the urge to wear the fins on swim sets later just to go faster.
Not quantity of yards or laps, but the number of times you get in the pool in a given week. You're much better off going three times at 40 minutes each time than to go twice and swim an hour. It's easy to lose the feel for the water, especially if you don't have a long history of swimming workouts. Of course, this doesn't mean quantity at the expense of quality. Try to be mindful of every stroke you take in the pool, especially towards the end of a workout when you are getting tired and feeling like you are falling apart.
With all that you have to do to get ready for a triathlon, swimming training needs to be done in the most efficient manner possible. Focus is the key to swim training in two hours a week and still having a successful and fun race.
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