The debate within the swimming world between high intensity, low volume training and lower intensity, high volume training started in the early 1980s. But within the triathlon community, the predominant approach is toward a lower intensity and higher volume program.
This belief is apparent in the classic 10x400-meter set for long distance training and long, straight swims regularly prescribed by triathlon coaches. These sets focus on training and athlete's aerobic capacity and to build enough endurance to swim 3,800 meters in open water.
Obviously, a volume approach to training requires a lot of hours in the pool every week. But completing 15,000 to 25,000 meters at a slow pace is not a volume approach and is an inefficient way to improve your swim leg. In the swimming world, high volume swim programs start at 75,000 meters a week.
For triathletes, big gains in the swim will come from improving stroke mechanics at the speed at which the athlete wants to race. Swimming 4,000 meters at a slow pace with sloppy technique engrains poor habits in the swimmer. Lastly, as coaches we strive to get the most out of the athlete with the least amount of training. The more efficient way to train for a faster triathlon swim is through a high-intensity approach.
You should structure your high-intensity program around specificity and building an efficient kinetic chain. Swimming faster with intensity and focus will naturally correct many swim stroke deficiencies.
As a triathlete, the fatigue generated from the bike and run and consistency in the water are two major challenges. If the athlete is too fatigued to hold focus and swim fast, then athletes will find it difficult to improve in the swim. Additionally, if the athlete is out of the water for too many days at a time, their feel for the water will diminish.
Athletes should swim at least four days a week to see improvement in their fitness and form, and less experienced athletes will need to swim more frequently. We've included a sample of a weekly swimming training plan for experienced triathletes below. For a less experienced athlete, cut the volume of the main sets by 15 to 25 percent.