Archives for posts with tag: prime numbers

After the time trials last week we are going back to work using some of the information we learned last week, specifically your current Critical Swim Speed (CSS).  As many of you will know your CSS is your lactate threshold swim speed, which is usually the pace you can sustain for a 1,500m swim.  We estimated your current CSS using your 400m and 100m time trial results and this was in the results I circulated last week.  If you didn’t do the time trials then you may know your CSS already but if not the average CSS for lane 1 is about 1m 26s/100m, for lane 2 is about 1m 37s, for lane 3 about 1m 44s and for lane 4 about 1m 55s.

The main set this week is return of the prime numbers set of 100s where prime numbered 100s (i.e. 2, 3, 5, 7, …) are swum on a slightly shorter turnaround than non-prime numbered 100s (i.e. 1, 4, 6, 8, 9, 10, …)  I would like you to swim the shorter turnaround 100s slightly faster than the others.  Aim for a 4s difference between the faster and slower 100s with faster 100s at 2s faster than your CSS and slower 100s at 2s slower than your CSS. This is a good long set and should help work on improving your CSS.

See you Saturday,


Prime numbers are one of the simplest ideas in Mathematics and also one of the most complex to understand.  They are taught in primary school when learning Mathematics yet also stretch the minds of some of the greatest Mathematicians today with some major unsolved problems.  They are used to create beautiful patterns, are the foundation of the security used to protect us on the Internet and also occur is many areas of nature.

What is Rob on, I hear you cry!  Has he hit the Christmas Sherry earlier than usual this year?!  What have prime numbers got to do with swimming?  The answer  to the first question is, alas, “no” and the second question is “not a lot”.  However, you will need to know all the prime numbers under 30 to be able to do the main set in the session this week.  So if you don’t know what a prime number is, a Prime Number can be divided evenly only by 1, or itself. And it must be a whole number greater than 1.  Hence, the prime numbers under 30 are 2, 3, 5, 7, 11, 13, 17, 19, 23 & 29.

See you Saturday!


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