A couple of notes here.
First, improve core strength and endurance. We all know the power you generate must pass through the core. Once your core fatigues, your form breaks down, compensation occurs, and you lose efficiency and increase risk of injury. Its important to keep a certain pelvic position when swimming, and the only way to do so is to improve core strength.
2. Antagonist work for injury prevention. Swimming places a high demand on the internal shoulder rotators as well as the scapula protractors. The lats and pecs are used heavily during swimming and will hypertrophy at a rate much faster than the external rotators of rotator cuff and the scapula retractors and depressors. So - train your mid traps/rhomboids, lower traps and scaption movement, and your external rotators.
3. Once you have built a better base, then we can start discussing ways to improve power. Obviously exercises that strengthen the lats, pecs, and deltoids will improve upper body.
4. Lower body. Having a large lower body is limiting in the water. It creates drag and will slow you down - thus, keep hypertrophy based lower body training to a minimum (ie. keep reps below 3, use a lighter weight and a faster speed of rep). However, the ability to "push off" the wall when turning is important to swimming performance. To improve this, you'll need to do movements that involve a triple extension: clean pulls, hang cleans, power cleans, etc. Also important will be plyometrics.
Br
