I'm building mileage towards a 20.6 mile swim in 12 to 13 months from now. I started training the end of May, 2007, but was able to complete a mile pretty easily. With Penny Dean's guidance, here is how I am training to get to 80% of the total distance by next July.
I will state right now that warmups are brutal on me. I need a very long warmup, unlike most people. I don't know why, but it just is, so I do it. I also only have access to the ocean, no pool.
Warmup:
1x800 broken by the 400. I even stop for 2-3 minutes at the 400 mark to catch my breath and regroup. The next 400 feels better. At the end of the 800, I hydrate on water and the product Rehydrate. Gatorade just does not help me.
Main Set: (Hydrate every 15 minutes to 30 minutes if possible)
Goal in May was 1-1/2 miles (actual miles) every other day. I broke it into half-mile swims hydrating every half-mile. Hydrating early prevents problems in the upper miles. Once the goal was met, I added another half-mile to reach two miles.
Two miles presented new problems due to poor conditioning. On days I was not doing mileage, I did anaerobic sets and sprint sets in the water. I also had to use small and large fins occasionally as I was fatigued. Fins allowed my body to swim the 2 miles on top of the water thus saving my shoulders from injury of which I have had some surgeries in the past.
June was an interesting month. Goal for June was 3 miles once a week. I would swim 3 days on, 1 day off and repeat this process. It helped a lot. I also use Stretch Cordz in the afternoons after a swim twice a week, but not on an off-day. When I reached the 3 mile mark, then I would lower the mileage for the next several days to 2-1/2 miles, 1 mile, sprint day, 2 mile, then a day off. Then another 3 mile swim. In June, I managed to get to 3-1/2 miles but it was a physical struggle.
July brought a new horizon. A 4 mile swim popped out of nowwhere, but I paid a price later. Couldn't move the next day. This led me to start doing Recovery Swims whereby you swim the day after a hard workout just to "recover." All the soreness/fatigue goes away in this swim. The recovery swim was only 3/4 of a mile and it was magic. The recovery swims helped me to not take days off.
I had to take 3 days off in July so when I returned, I decided to swim until I dropped. I managed my first 7 mile swim. It was unplanned. I wasn't ready but I did it. I went into lactic acid lockup, a scary thing that many runners have experienced. I did a recovery swim the next day of 2 miles, then I lowered the mileage to 3-1/2 to 4-1/2 every other day. Still doing sprints and anaerobic drills on days inbetween.
So now it is August and I am swimming 4-1/2 to 6 miles every day for 3 in a row, then I lower the mileage for the rest of the week. Do a recovery swim, one day off, and build again.
Summary:
Choose a long swim day and try it. Do a recovery swim the next day. Lower the mileage for 3 days in a row to something manageable. Take a day off, or two if you need it. Then build the mileage back up to short of your long swim day. If 6 miles is your long swim day, do 4, 4-1/2, 3 before that long swim. If 3 miles is your long swim, do 2, 1, 1-1/2.
Good news:
you will find that as your mileage goes up, your lower miles become ez and powerful and faster. An enlightening experience and confidence builder.
Sorry this is long but it is a lot of background. Next round will be actual workouts without so much narrative!! Happy swimming!
