best training for o.w.

I don't know about "continuous," but I think if you are aiming at an event that will keep you swimming for 30 minutes or more solid you need at least once per week to swim for that long or longer without really letting up. A short-rest interval set is probably a better way to accomplish that result in the pool than a continuous swim; it gets the intensity up, and the clock keeps you honest on effort and pace. I have been pretty successful in distances up to 5K and I never do a straight 5K in workout. I think you need to train four skills to succeed at OW swimming: 1. Your heart needs to be able to maintain an elevated rate for as long as your swim lasts. You don't have to train this skill in the water, although you can if your skeleton can take the repetitive strain. I like cross-training for the heart because it alleviates strain on the swimming muscles and joints. I used to run; now I go to spin class. 2. Your swimming muscles need to be able to work for as long as your swim lasts. You do have to train this skill in the water, but you don't have to train it through continuous swimming. You just need to make sure that your workouts are long enough, with enough sustained effort overall, to build enough muscular endurance to last the swim. Assuming your goal swim is going to take you 1.5 hours or less, you should probably aim to have at least one workout per week that is longer than your actual goal swim. 3. You need to be able to swim fast in bursts. At the start, you need to stay with the pack that you want to finish with. You might need to pass someone, or get away from some irritating toe-tapper. You have to train this skill in the water, too, through fast swims. Maybe you don't need as many 50s on 3:00 as a sprinter, but you could use a few. This skill is my weakest, but I am working on it by training for (and going to) pool meets. 4. You need to be able to navigate. You pretty much have to train this skill in OW. The better you get at sneaking a look without breaking your alignment or cadence, the faster you will be. If your swim lasts more than about 1.5h, you will probably need to drink and eat during the swim and you need to train those skills too. Likewise, the event will probably require that you have an escort craft, and you will want to practice with that person. I have never done such a swim, though, so I don't have any insight about practicing for one.

I don't know about "continuous," but I think if you are aiming at an event that will keep you swimming for 30 minutes or more solid you need at least once per week to swim for that long or longer without really letting up. A short-rest interval set is probably a better way to accomplish that result in the pool than a continuous swim; it gets the intensity up, and the clock keeps you honest on effort and pace. I have been pretty successful in distances up to 5K and I never do a straight 5K in workout. I think you need to train four skills to succeed at OW swimming: 1. Your heart needs to be able to maintain an elevated rate for as long as your swim lasts. You don't have to train this skill in the water, although you can if your skeleton can take the repetitive strain. I like cross-training for the heart because it alleviates strain on the swimming muscles and joints. I used to run; now I go to spin class. 2. Your swimming muscles need to be able to work for as long as your swim lasts. You do have to train this skill in the water, but you don't have to train it through continuous swimming. You just need to make sure that your workouts are long enough, with enough sustained effort overall, to build enough muscular endurance to last the swim. Assuming your goal swim is going to take you 1.5 hours or less, you should probably aim to have at least one workout per week that is longer than your actual goal swim. 3. You need to be able to swim fast in bursts. At the start, you need to stay with the pack that you want to finish with. You might need to pass someone, or get away from some irritating toe-tapper. You have to train this skill in the water, too, through fast swims. Maybe you don't need as many 50s on 3:00 as a sprinter, but you could use a few. This skill is my weakest, but I am working on it by training for (and going to) pool meets. 4. You need to be able to navigate. You pretty much have to train this skill in OW. The better you get at sneaking a look without breaking your alignment or cadence, the faster you will be. If your swim lasts more than about 1.5h, you will probably need to drink and eat during the swim and you need to train those skills too. Likewise, the event will probably require that you have an escort craft, and you will want to practice with that person. I have never done such a swim, though, so I don't have any insight about practicing for one.