I did a practice shave of my legs last night, to get used to it and also figure out how long it takes me for planning purposes.
Today in practice, I was faster than usual. The most obvious was in my 200 free warm-up. I dps the first 100 and then gradually speed up to about 75%. Usually I am around 3 minutes. Monday, I went 2:51. Today, I was 2:36 with the usual effort level.
My 200 *** warm-up was about 10 seconds faster than usual.
Can shaving really improve things that much? Is some of this because I am tapering?
Also, for those guys who shave your heads, do you also wear a cap? If not, is the bald head better than a cap?
Laminar flow is not necessarily advantageous from a drag reduction standpoint. Consider the flow around a cylinder: www.princeton.edu/.../blunt.html
You actually want flow separation to occur earlier (as in the turbulent case) because it creates a smaller wake. Now the question is whether or not a swimmer in the water is anything like a cylinder. In a streamlined position we should create less drag than a cylinder, but we aren't exactly airfoils, either.
I write software now so keep in mind that my mechanical engineering backgound is very fuzzy. I did like fluid dynamics since it applied well to my sailing hobby. With that in mind, I recall that drag is reduced in turbulent water. That partly explains why swimming in someone's draft improves performance. I used to wonder if it would improve the performance of a sailboat to place a tripwire just below the water at the bow of the boat. The problem with that is the boat isn't a cylinder... it is a streamlined shape and you want to keep the laminar flow and reduce skin drag as much as possible.
Humans are a bit different that boats. We are forced to surface at 15m at which point our streamlined shape is lost. At some point, we are better off on top of the water either because we can propel ourselves faster than we can SDK or due to threat of disqualification. So, we transition from a streamlined shape to a not quite so streamlined shape at some point. If I read the link right, during the streamlined phase, we are more concerned by skin drag. This is where I believe shaving makes a difference if it does at all. Once we break streamline, pressure drag is more dominant and we prefer turbulent water for wake reduction.
As to Chris' links, they sound good but don't talk much about methodology for quantifying the physiological components. I'm sure the referenced papers address that in some way. One comment he made struck me as odd: "Shaving does not reduce water resistance nor eliminate the amount of friction on the skin." That's a pretty bold statement as hair folicles would at the very least increase the surface area on the boundary layer. I don't think anyone is arguing that shaving has no effect on drag... its a matter of whether it has negligible effect or not. I'm also a bit skeptical about whether or not the physiological response (if it exists) is due to a change in how the nervous system senses water after a shave or due to a placebo effect. The write up makes some compelling arguments for the former and I'm hardly qualified to debunk any of this... nor am I up for digging through research papers at the moment.
Laminar flow is not necessarily advantageous from a drag reduction standpoint. Consider the flow around a cylinder: www.princeton.edu/.../blunt.html
You actually want flow separation to occur earlier (as in the turbulent case) because it creates a smaller wake. Now the question is whether or not a swimmer in the water is anything like a cylinder. In a streamlined position we should create less drag than a cylinder, but we aren't exactly airfoils, either.
I write software now so keep in mind that my mechanical engineering backgound is very fuzzy. I did like fluid dynamics since it applied well to my sailing hobby. With that in mind, I recall that drag is reduced in turbulent water. That partly explains why swimming in someone's draft improves performance. I used to wonder if it would improve the performance of a sailboat to place a tripwire just below the water at the bow of the boat. The problem with that is the boat isn't a cylinder... it is a streamlined shape and you want to keep the laminar flow and reduce skin drag as much as possible.
Humans are a bit different that boats. We are forced to surface at 15m at which point our streamlined shape is lost. At some point, we are better off on top of the water either because we can propel ourselves faster than we can SDK or due to threat of disqualification. So, we transition from a streamlined shape to a not quite so streamlined shape at some point. If I read the link right, during the streamlined phase, we are more concerned by skin drag. This is where I believe shaving makes a difference if it does at all. Once we break streamline, pressure drag is more dominant and we prefer turbulent water for wake reduction.
As to Chris' links, they sound good but don't talk much about methodology for quantifying the physiological components. I'm sure the referenced papers address that in some way. One comment he made struck me as odd: "Shaving does not reduce water resistance nor eliminate the amount of friction on the skin." That's a pretty bold statement as hair folicles would at the very least increase the surface area on the boundary layer. I don't think anyone is arguing that shaving has no effect on drag... its a matter of whether it has negligible effect or not. I'm also a bit skeptical about whether or not the physiological response (if it exists) is due to a change in how the nervous system senses water after a shave or due to a placebo effect. The write up makes some compelling arguments for the former and I'm hardly qualified to debunk any of this... nor am I up for digging through research papers at the moment.
