Ironman Mark

I asked myself this question a while ago and came up with the answer of 40s per 400m.  But this was based on a pool swim where there are push off and glides every 25m.  So what’s the difference in open water?

Well I went to the lake yesterday and, after a little persuasion, decided to swim without my wetsuit.  I decided to push one length, which is around 400m, quite hard.  In fact, it probably was “hard”.  Definitely not “all out” but I guess I might have been able to go a fraction quicker.  My watch said 6:43 for the lap.  So how does that compare?

Well last week I did a few lengths with my wetsuit on – very easy, easy and moderate.  The very easy one was 7:30, reducing to 6:40-something for the moderate one.  So the difference between with wetsuit and without is the difference between a “moderate” effort and a “hard” effort. 

But I like numbers so what’s the time difference?  Well, on 11 May I did some intervals in the lake which included 3 hard laps, done in: 5:55, 5:52 and 5:58.  I’ve not done much swimming since Lanzarote so I may well have lost some swim fitness.  But if I haven’t the difference is around 46s or so.  Let’s say I have lost a bit of swim fitness and 6:43 was a little on the easy side of hard then that 46s ties in very well with 40s.

So, I am going to claim that I am 40s per 400m quicker with a wetsuit.  Nice

Last year, I would have said that it was 30 seconds per 400m quicker.  In June 2009, my personal best for 400m was 5:55 without a wetsuit and 5:25 with a wetsuit.  Both of these were done when I was feeling pretty fresh.

Today, I went to the pool to check that the moths had not got to my wetsuit.  I only did the first half of my session with it on because I felt like a boil-in-the-bag.  The fast 400m in the sessions are normally done in around 6:09 to 6:12.  The quickest has been 6:03 on a day when I had some good motivation (someone behind me and I was feeling angry). 

The first fast 400m was in 5:31. I was going fast, but not pushing it fast.  The next fast one was 5:25 (with the first 100m on 1:17, reaching 200m on 2:40).  This was pushing it fast but again not all out.  The last one, without the wetsuit was again pushing it fast and came in at 6:09.  Normally, I would be chuffed at 6:09.  But to get 5:25, wow! 

So how much quicker?  I am not sure because none of the 400′s were “all-outs”.  If the 5:25 was equivalent to my previous best of 6:03 then that is 38s per 400m’s quicker.  I don’t think I pushed the 5:25 as hard as a 6:03, so I am going for 40s per 400m.

That’s 10s per 100m quicker!

But I am not sure that that is realistic.  It sounds too much more than the 7.5s per 100m last year.  So why the increase?  Well, part of it will be differences in perceived effort.  Part of it may be differences at less than “all out” speed.  Who knows.

What I need to do now is do a full session in the suit, see how all three quick 400′s are.  Also see how quick the moderate and easy 400′s and compare them too.  If the moderate/easy ones have the same time differential then I know that I wasn’t going all out on the fast 400m. 

So then the question is how quick could I go if I was doing an all out 400m rather than as part of a 4,000m set?  Also, how quick could I do it if I was feeling fresh rather than my permanently tired state?  I think I could do sub-5:20.  A bold statement but I think that is reasonable.  Once Lanza is out of the way, I’ll give it a try.