My answer - the obvious cop out, all of the above! You need some interval work to stretch your threshold and maxVO2 levels, some long swims for basic endurance and mental toughness, and plenty of technique work.
Technique work may be the most important element of any swim training plan because water is thicker than air, and maximizing swimming efficiency has a big pay-off. The pay-off may not be a faster time, but if you can go the same time with less energy, you have more energy left for the bike and the run.
Ask yourself how important it is to win the swim portion of a triathlon compared to how you will perform overall. The longer the race, the less likely it is that the winner of the swim is the winner of the triathlon. But if it takes all you've got just to get through the swim, you are going to face a big challenge completing the bike and run.
This is a plan I recommend for Olympic distance or longer triathletes (1,500 meters or longer swim legs). This plan will work for shorter triathlons, too, but to maximize those performances requires more interval work.
In running terms, compare plans for those racing a mile versus a 5k, 10k, and 1/2 marathon. The 5k, 10k, and 1/2 marathon plan are much more similar to each other than the mile plan. Same for swimming. An Olympic distance swim, 1,500 meters, is going to take 15 minutes (with a good current) or longer. That means the emphasis of the training will be sub-threshold, since the race is at this level. If you go faster than that in the swim, you won't have much left for the bike or run once you do get out of the water.
To use this plan, the athlete should currently be able to:
- Make it to the pool at least three times a week
- Complete at least 45 to 60 minutes of training each session
- Complete a set of 10 x 100 meters on an interval of at least 3:00
All workouts should include:
- 5-10 minutes of easy swimming and kicking to warm-up
- 5-10 minutes of technique work
- 5-10 minutes of easy swimming (and more technique work) to cool-down
Workouts are done in 4 week blocks, then repeated with minor modifications if needed. I recommend separating each swim workout by at least one day (swim every other day or every third day).
Swim with a master's team? Make that your third and/or fourth workout of the week, and take advantage of the coach's eyes and expertise to help you with your technique.
You may want to add or substitute an open water swim for the straight swim every other week as you get closer to your race. This should help you learn some navigation skills and how to work with waves and currents (remember to only do open water swims in safe, guarded locations).
