Heather Fell: Which is better? This or this? Now, I'm talking about closed versus open fingers.
I've personally had a bit of criticism over the years as I swim with rather splayed lazy fingers.
I thought it was time to look at the science and find out whether I'm actually optimizing my stroke
or are open fingers a little bit lazy. [music]
Depending on when and where you were taught to swim, you might remember
specifically being told to swim with your fingers closed or close together. Now,
I remember being told to make sure that my fingers were touching so the water couldn't
slip through my hands. At that time, that seemed very logical. After all,
we do go on about the catch of catching that water and making sure you've got a hold of it. Surely,
when you're catching something, you want to make sure you've got it securely in your hand.
Well, I am genuinely asking these questions as I don't actually know the answer. I also don't know
why I don't swim with my fingers close together. Today, I'm hoping that science, rather than just a
swimming trend, is going to help us answer this. [music]
I want to start by looking at what happens to the hand as it moves through the water
irrelevant of finger position. In cycling, we have aerodynamics. It's time to look at
fluid dynamics for swimming. The larger the surface area, the larger the drag coefficient,
so if you're moving a larger object through the water, it's going to take more energy to move it.
On the flip side, it can result in more propulsion as a result of moving it. As you move the hand or
any object through the water, it will have a boundary layer of water around it. It's this
layer that acts to resist movement and acts as an extension to the object, or in this case,
an extension to the hand and the fingers. This layer can vary in thickness depending on a few
factors which we'll touch on in a moment. [music]
The final effect of the hand moving through the water is the vortices as the water flows
around and behind it. When you think of the swimming stroke, the speed is actually
not enough, and the amount of water that's flowing isn't enough to have really much of an impact. Add
to that the turbulent water in a pool or open water, and it all becomes rather negligible.
Let's go back to the first point, the surface area. Actually, as human beings, we can't really
do much to alter that. If you think about the hand, you could maybe squeeze your fingers really
close together to decrease the surface area of your hand and you could stretch your hands as wide
apart as possible and maybe get a little increase in that surface area from the webbing between your
fingers, but overall, it all becomes negligible. [music]
It's, therefore, this thin boundary layer that actually has the greatest effect
on the drag coefficient as your hand moves through the water. This layer acts as an extension to the
fingertips, to the end of your hand, but also, if your fingers are splayed,
it's going to add to the area widthways either side of the fingers as well.
The size of this can be affected by the speed that your hands are moving through the water,
the shape of your fingers, as well as how far apart or how close together they are.
Most notably, all factors which you can control. [music]
The evidence indicates that you want to have your fingers apart in order to increase
that boundary layer, which will then increase the drag coefficient, but the big question being
how wide apart do you want your fingers? Well, ideally, in theory, you'd want to have them
double the width of that boundary layer, so you've got the boundary layer of one
finger next to the boundary layer of the other finger meeting in the middle.
If you've got your fingers too wide apart, then the water will slip through them and too close
together and you're simply limiting that potential boundary and potential force of your swim stroke.
The boundary level varies from hand to hand, as I expect you realize with so many variables,
it's going to be hard to have an exact distance. The research comes up with distances from 3 to
8 millimeters. We could get a ruler out for that, but it's fairly small and looks pretty
much like the position of fingers in a relaxed hand. That's kind of handy as, realistically,
are you going to be able to get your fingers at exactly 8-millimeters apart? No, I think not.
Are you able to relax your fingers so they're not touching? Yes, probably. There's enough to
think about when swimming without trying to find a 3 to 8-millimeter gap between your fingers.
Did you pick up the keyword there? Relax. Basically, most of the evidence points to a
relaxed hand being the optimum. If you do manage to find that perfect amount of separation between
your fingers, apparently it can increase your drag coefficient of your surface area by up to 9%.
Having looked through all of this research though, I found very little, well, basically nothing on
the hand entry. I guess, our hand entries do vary so much from person to person and stroke to
stroke. If you think about someone with a straight arm recovery, then their hand is probably going to
be slapping down and coming very much sort of all at once into the water compared to someone
who's got a very delicate finger-first entry. I would just logically think that especially if
you're someone with a finger-first entry, that you want to have your fingers closer together
to reduce that resistance as your hands are going into the water, and then as you start your catch,
that is where your fingers need to become nice and relaxed, distance apart, to make your stroke
as efficient as possible. [music]
I've got one final point which could actually put a spanner in the works of what we've talked
about so far. It's a question. Do you actually want to increase that surface area at your hand?
There's lots of plus points, obviously, for the same stroke rate, you're going to be able to pull
more water on each stroke and therefore go further for each stroke, but you need to think about it.
You've actually got to be stronger to be able to take that extra pressure that your hands
are going to produce. It's almost like swimming with paddles, and that requires
a time of building up that strength and also doing some extra strength and conditioning exercises, so
you might want to think about that one. Anyway, I want to finish by saying that maybe my
lazy hands aren't such a bad thing. After all, a relaxed hand is going to lead to a relaxed stroke,
which makes you more efficient and able to swim without getting tired.
Next time you're in the water, have a think about what you're doing and give it a try
and watch your fingers. Let me know what you're doing. You can do that in the Comments section
below. Give us a like if you've enjoyed it and do follow us on our social media channels,
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