The TI (Total Immersion) Family of Swim Drills
This series of swim drills mainly addresses balance and streamlining issues. But, once you fix your balance issues, avoid these drills because they tend to slow swim cadence and increase front end glide.
If you have: Poor balance, straight arm recovery, cross-over and/or disconnected shoulders and hips.
Swim 100-yards, the first 50-yards with closed fists, and the second 50-yards with open hands. This helps to improve the catch phase of your stroke, by making you very conscious of your arm and hand positions, following the fist lengths.
If you have: Missed catch.
This helps to improve swimming-specific strength and the catch phase. Using paddles in an aerobic manner, similar to the 50 fist/50 free drill, forces you to become more aware of your hand positions, through the entirety of your stroke.
If you have: Missed catch, weak back end, and/or strength limiters.
Ankle bands shut off a swimmer's kick, forcing them to balance their body in order to create a more productive forward pull. Forward velocity helps create balance and is a function of good mechanics. This swim drill is very effective for most triathletes, as it addresses almost all common deficiencies.
If you have: Any of the above issues.
Tabata intervals are a great tool for improving turnover. Do these once or twice each week by sprinting 25 yards while focusing on high stroke turnover, followed by a 10-second rest, and repeat eight to 10 times. Do two sets with two minutes rest in between.
Single Arm Swimming
If you have: Poor timing and/or low swim cadence.
Single arm swimming is the number one way to connect a swimmer's hips to their shoulders. With one arm out in front, stroke with the other arm. Once you master this, hold the arm that is not stroking at your side.
If you have: Disconnected shoulders and hips.
Swim cord routines are an excellent way for swimmers to help ingrain good arm position and the elusive high elbow. It is always easier to work on these items with the consistency of dry land, than in the multi-variable environment of the water. Swim cords also help to target potential strength limiters in swimmers with relatively low body mass index (BMI).
If you have: Missed catch, weak back end, strength limiters.
Believe it or not, cognitive thought can address all of the above issues. All of the drill work in the world is useless if you are not thinking about your swim mechanics with each and every stroke. For example, thinking "fingers tips down, wrist aligned" early in your swim stroke can help to create a higher elbow and faster cadence.