Hourglass Dolphin
Open-water swim workout (total time: 60 to 70 mins)
Open-water sessions are fun when done in a group environment and simulate race conditions with other athletes. It's easy to go for an open-water swim on your own and do intervals, but that won't prepare you as well for race conditions (with arms and legs are flying around you and having to do buoy turns and navigation). I get my athletes do their open water sessions as key swims for the week. My advice: Gather a group of training partners and hit the water!
10 to 15 mins easy swimming warm-up
4 x (10 strokes hard, 10 strokes easy, 20 strokes hard, 20 strokes easy, 30 strokes hard, 30 strokes easy, 20 strokes hard, 20 strokes easy, 10 strokes hard, 10 strokes easy); 30 secs rest between each set
4x (20 strokes butterfly, 20 strokes backstroke, 20 strokes breaststroke, 20 strokes freestyle) Descend sets 1 to 4 (first set is easy, fourth set is hard) 20 secs rest between each set
3 to 5 minutes easy swimming back to shore
Main set
8 to 10 x running start out to, and around, buoy and back to shore (approx. 8 to 10 x 150 to 200 m efforts) with 1 min rest between.
- Use a buoy/marker of some sort that is approx. 75-100m off shore
- Start each effort as a group (as you would in a race start)
- Rest is 1min after final finisher
- Stagger start if large numbers (weaker swimmers slightly before stronger swimmers, so they meet at marker together)
- Shore to buoy/marker efforts are the odd numbers
- Buoy/marker to shore efforts are even numbers
- When running out: high knees, strong arm drive, duck diving if possible, high stride rate, good sighting, drafting.
- When racing in: with waves, watching under your arm for wave to pick you up, staying stiff on wave, knowing when to stand up, run up beach hard
- Option: If doing in surf and wave running, then the efforts can be broken into 16 - 20 x 75 m where you race each way (i.e., shore to buoy, rest and re-group and then from buoy to beach trying to catch wave in and run up beach)
- Option: If wanting longer efforts, use buoy further away and adjust intensity (ie., 8 x 300 efforts)
Warm down
10 to 15 mins easy swimming
Source: http://www.ironman.com/triathlon-news/articles/2013/06/ironman-101-swim-workouts.aspx#ixzz5MzU5tdxM