There are generally two types of people who seek out swim help for their triathlon:
1) Novice: This person hardly swims or may not be able to swim at all. They have not done a race yet or have done one but floundered.
2) Advanced beginner/intermediate: This person has done a few races but feels like they don't get the swim portion. They don't have great endurance and become wiped out after a long swim.
To improve, both types should spend some time performing two basic drills: kicking on your side and shark-fin drill.
Side kick: Kick with your hips and shoulders rotated to the side, keeping your head still while looking at the bottom of the pool. Extend the arm closest to the bottom of the pool straight out in front and hold your other arm against the side of your body. When you need air, rotate on to your back, take a few good breaths, and then return to the kicking position. Do the odd numbered lengths on the right side and the even numbered lengths on the left.
Shark fin: Start in the same position as you would for the side-kick drill. Lift your elbow on the arm closest to the surface of the water up toward the sky. Drag your hand through the water until it reaches your goggle line (or until you've made a shark fin). Slide the hand back down your body to where is started, roll onto your back, grab some air and repeat. Remember to keep your eyes looking directly at the pool bottom. Again, do the odd numbered lengths on the right side and the even numbered lengths on the left.
These drills are designed to improve your balance in the water, head position and overall body position.
Novices should practice both drills until they feel more balanced in the water. If you have them, use fins at first. If necessary, I recommend taking a whole month to master these drills before moving on to more advanced drills and swimming sets.
Advanced beginners and intermediates should move on to more advanced drills after working on the basics for a week or two. Your focus should shift to improving stroke technique. You can do this with drills such as swimming with a closed fist or dragging your fingertips as you swim freestyle. At this point you can start mixing in longer swimming sets as well.
Here's a general sample training program for each type:
Novice swimmers: 14-week training plan for next race
Weeks one and two: Side kicking and shark-fin drills for as long as your are comfortable. Try to increase yardage with each pool session. (No swimming)
Weeks three and four: Practice the more advanced drills with some swimming mixed in (75-percent drills, 25-percent swimming)
Weeks five and six: Drills combined with swimming (50-percent drills, 50-percent swimming), while building yardage slowly.
Weeks seven through 10: Work on building up yardage and on some interval training (75-percent swimming, 25-percent drills)
Weeks 11 and 12: Continue to build yardage and work on intervals (80-percent swimming, 20-percent drills)
Weeks 13 and 14: Taper. Back off intensity and yardage (80-percent swimming, 20-percent drills)
Sample workout:
(50-percent drills, 50-percent swimming)
Warmup: 300, alternate kick/swim by 25
Drills: 6x75's, 50 shark-fin drill, 25 swim. Rest 15 seconds between each 75
Main: 4x100's freestyle, build each 100. Rest 15 seconds between each 100
Cool down: 100 swim, breathe every three strokes
Advanced Beginner/Intermediate: 12-week training plan for next race.
Weeks one and two: Start with basic balance drills and move to more advanced drills, slowly adding in swim strokes (80-percent drills, 20-percent swimming)
Weeks three through six: Build yardage. (75-percent swimming, 25-percent drills)
Weeks seven through 10: Peak training. Keep building your yardage and lowering your interval time. (90-percent swimming, 10-percent drills)
Weeks eleven and twelve: Taper. Back off yardage and intervals while focusing on technique. (90-percent swimming, 10-percent drills)
Sample workout:
(50-percent drills, 50-percent swimming)
Warmup: 300, every other 50 kick on your side
Drills: 6x100's, 50 shark-fin drill, 50 swim. Rest 15 seconds between each 100
Main: 4x150's freestyle, build each 150. Rest 20 seconds between each 150
Cool down: 100 swim, breathe every three strokes
Remember, never sacrifice technique for speed. If you feel your stroke is slipping or you're not ready to advance to the next level, keep hammering the drills. There's no hurry. The above training plans are very generalized. You will have to be your own judge of ability and adjust accordingly for your level and your goals.