Originally Posted by giersbergen
are there any suggestions on what distances/practises I should be concentrating on pursuing to improve my overall time for the mile?
Welcome--sounds like you're off to a good start judging from your times. To get faster, here are a few ideas:
1) Make practicing technique (balance, streamline, precise body positions and motions, smoothness, lack of splashing, etc) your main priority. You will gain far more speed doing this than you will by focusing on fitness and working "hard" at your swimming. Smooth is fast!
2) Speed depends on two variables: your stroke length, or how many strokes it takes you to swim one length (SPL), and your stroke rate (SR). Improve one (lower SPL or higher SR), or both, and you'll be faster.
3) Generally, speed comes from swimming shorter faster repeats with longer rests (e.g. 10 X 50m or 5 x 100m with 2:00-3:00 rest between repeats).Endurance comes from swimming longer, slower repeats with less rest (e.g. 5 x 200m with :30 rest between repeats, or a pyramid like 275m-250-225-200-175-150-125-100-75-50-25 with :10 rest between each repeat (that last one is a broken mile set I've been doing lately). I do some of each type of training every week, usually focusing more on one than on the other but including a bit of both each session.
But really, ALL speed comes from consciously and mindfully manipulating SPL and SR. To begin, make sure you are swimming at an efficient range of strokes per length based on your height/wingspan, and make doing that your first priority if you can't do it now--that's where you'll find your biggest gains. Coach Mat has a great introduction to this idea here:
Then organize much/most of your practice by experimenting with different combinations of stroke length and stroke rate. A tempo trainer (TT) can be incredibly useful to work toward a faster stroke rate (lots of good threads on this forum about using a tempo trainer).
Once you have a good range of SPL that you can swim comfortably, you can do sets like this without a TT to practice gears and pacing:
7 x 50m at 13 SPL, 14 SPL, 15 SPL, 16 SPL, 15 SPL, 14 SPL, 13 SPL
Your times will get faster each time you add a stroke, and you'll keep some of that speed as you descend the pyramid back down to longer strokes.
On longer repeats, I'll often pace myself by choosing different SPL for different segments. For example, on a 400 swim, I might do this:
100m at 14, 14, 14, 14 SPL
100m at 14, 14, 15, 15 SPL
100m at 15, 15, 15, 15 SPL
100m at 15, 15, 16, 16 SPL
This will give me negative splits (faster at the end), which is generally the fastest way to pace yourself.
It's really ALL about manipulating SPL and tempo when you are looking to get faster. Enjoy the journey!