To quote Gull: What is the right mix of technique and endurance for a Masters athlete (who wants to be competitive, say, at Nationals) with a finite amount of time to train?
Slowfiish,since you aren't training to sprint I wouldn't recommend you sprint,but I would recommened you shorten your distance in your intervals.I'd say start with 50s at your "swim pretty" speed(the speed at which your stroke looks the best.) Make the interval some thing comfortable at first(on the min. on the 1:30 what ever works for you). Depending on your conditioning now do 1 0r 2 sets of 5-10. As that gets easier shorten the interval. When you can "swim pretty for a 100 start adding 100 sets. Then go to 200 sets. When you are doing 200s start trying to "swim pretty" faster. I think it is important to go a speed and distance so that you can keep good technique,but the more you practice the longer you can do that.
Slowfiish,since you aren't training to sprint I wouldn't recommend you sprint,but I would recommened you shorten your distance in your intervals.I'd say start with 50s at your "swim pretty" speed(the speed at which your stroke looks the best.) Make the interval some thing comfortable at first(on the min. on the 1:30 what ever works for you). Depending on your conditioning now do 1 0r 2 sets of 5-10. As that gets easier shorten the interval. When you can "swim pretty for a 100 start adding 100 sets. Then go to 200 sets. When you are doing 200s start trying to "swim pretty" faster. I think it is important to go a speed and distance so that you can keep good technique,but the more you practice the longer you can do that.