Are you referring to dry land exercises or water? Also, what are the distances you are trying to compete at/complete? What is the stroke you are trying to improve? Are you trying to improve your stamina or your speed? All of the above questions are important when it comes to determining the best exercises to improve swimming technique. The exercises Joanne and Calvin mentioned are very helpful, but I would also agree that hiring a swimming coach would be a great idea as well. If your technique needs to be improved, the coach would be the best person to help you since he/she can observe you in the water.
I have a client who is an open water swimmer whose goal was to improve her swimming strength.
Here is the approach we took as far as training was concerned.
We focused on resistance training for endurance as this type of training transfers well into the water. I incorporated balance exercises on the BOSU ball in a prone position as this is the position that she is in when she swims.
However, the most important thing for her to do was to simply swim.
In exercise science there is a principle that states that the body will adapt according to the way we train it. So, if you want to improve your swimming, swim more.
It probably won’t be a bad idea to hire a swimming coach.
All the best!
If you are referring to dry land exercise that would carry over to the waters, you can always do whip kicks with your feet on glider pads. Other than that, a lot of different core work to improve your body’s co-ordination in the water. You probably want to have movements that will mimic the movements you will likely do in the water. Perhaps the use of the TRX would be an appropriate tool for this kind of training as well.