Perhaps the greatest difference in strength training lies between the two ends of the swimming spectrum—sprint and distance athletes. Sprint athletes need to harness quick muscle recruitment by developing a greater density of fast twitch muscle fibers. This can be achieved through strength training that focuses on power and speed. Sprint athletes require a longer preparatory phase leading up to their power phase because they will execute more extensive power lifts than distance swimmers. This prep work is necessary so the athlete can learn progressions for power movements, prevent injury, and ensure the proper muscles are recruited using good technique.
On the other hand, distance swimmers need to simulate their experience in the water with strength exercises that emphasize stability and endurance. The repetitive nature of their swimming requires greater stability in the shoulder girdle, hip capsule, and core to create more efficient long-axis rotation. In strength training, this translates to less power work and more stability work. For example, if a sprinter will be doing a bench press using the barbell, a distance swimmer may execute the bench press using dumbbells while lying on a swiss ball (also known as a physio ball). This variation makes the athlete work hard to remain stable during the repetitions. Distance swimmers may execute more bodyweight exercises than sprinters. One example would be doing sets of pushups with upper body rotation to mimic the body position of freestyle.
Middle distance athletes will much more closely approximate the sprinter program. If you swim mostly 200-meter races or less, you will need to integrate power into your strength training.