Just wondering how much time an average swimmer drops in Chattanooga with the flow of the river?
I swam IMLP in 2011 in 77 minutes, wondering what I should expect to drop in Chattanooga? (I am on pace now to be like 5 minutes faster)
I swam it in 50 minutes.
Mr PR was 70 minutes in Cananda
I was faster than that, but not <60 shape.
The popular guess was 12 minutes faster.
But its way more important to know the flow rate on your race date.
And it seems incredibly hard to predict accurately.
Just wondering how much time an average swimmer drops in Chattanooga with the flow of the river?
I swam IMLP in 2011 in 77 minutes, wondering what I should expect to drop in Chattanooga? (I am on pace now to be like 5 minutes faster)
There is really no way to say in advance of the day of the race. The race will get whatever flow TVA’s water engineers decide is appropriate given the weather forecast, power production needs, flood control, water quality considerations, etc. You might have zero flow in the river or a high flow that would improve your time by 10-15 min. I used to work in TVA’s water group so I have some knowledge of their inner workings:)
If I remember correctly, at the athletes meeting for the 70.3 in May they said the dam was dumping over 25k cfs for the prior year’s 140.6 but they were targeting 6kish for the 70.3. If the flow is closer to the 6k level I’m guessing you’ll pick up 7-12 minutes. Wild ass guess on my part given I swam 32:29 for the 1.2, which was 4-5 minutes faster than I expected.
My swim in May was a pr by 2 min at 70.3 distance, 25.5 minutes. Current was hardly noticable.
My swim in May was a pr by 2 min at 70.3 distance, 25.5 minutes. Current was hardly noticable.
Yeah I didn’t notice any benefit from current while swimming or with my time afterwards
20 minutes on that day - as others said it depends on what the river is doing on race day.
I swam 5 minutes faster than normal at the 70.3 in May. I didn’t notice much current but what stuck me was how much room everyone had. It was wide open pretty much the entire time with almost no contact with other swimmers. It felt like a practice swim and at times I had to look around to make sure I hadn’t gone off course.
Two of my friends did it in 58 and 60? They are usually around 1:14-1:18 IIRC.
I did it in 1:03 (I believe) and I am usually a 1:15-1:17 full IM swimmer.
As others have stated, it is hard to predict the flow because there are so many factors that influence the TVA’s decisions. Rain is more prevalent in the fall than the spring (in east TN) so it may be that the expected flow would be higher in September than May.
If you get what we got last year you can expect a fast swim. It was crazy fast. I swam 57 minutes and I think I’ll be about 1:20 this year in IMLP.
Honestly, the only thing that can go wrong with a current that fast is that if you get pointed in the wrong direction off the dock it takes some effort to get back on track. You can’t see the dock or the river till you’re practically jumping in. My friend who is much faster than me and we started at the same time - headed off to the right from the dock and by the time he realized he was practically in the middle of the river. So, where he would normally be faster than me he came out a few minutes behind me because he had to get all the way back across the river.
For the 70.3, swimming upstream, my pace was ~1:20 / 100 yd and downstream ~1:05 / 100 yd, so figure 7.5 sec/100 yd or ~2.5 minutes.
I swam about 41 and I am typically a 52 minute swimmer. However I think the slower you are the more benefit you get from the current. I also think it depends on what the TVA does with the river flow on the day of the race. If the conditions are exactly the same as last year I would say 10-15 minutes is a pretty safe bet.
Better question is what time will you get if you just float like a log…
the 70.3 this year was 350 M up stream, then turned down stream.
Not sure if this made too much of a difference. The current was almost nothing race morning.
Curious if slower swimmers do actually benefit more from current than faster swimmers? Is there any science to back this up? Wouldn’t someone with a near perfect stroke be able to add more speed with a current pushing them than someone in the same current with a crappy stroke?
Curious if slower swimmers do actually benefit more from current than faster swimmers? Is there any science to back this up? Wouldn’t someone with a near perfect stroke be able to add more speed with a current pushing them than someone in the same current with a crappy stroke?
Think about this way: if you’re swimming 1 mph in still water, but then race with a 2 mph current, then your speed is around 3 mph (not exactly additive but fairly close). If you are a 2 mph swimmer in still water, then race w/ 2 mph current, then you’re going 4 mph roughly. So for a 2.4 mi swim:
1 mph in still water ==> 2.4 hr or 2:24 swim
1 mph + 2 mph current ==> 0.80 hr or 48:00 swim
2 mph in still water ==> 1.2 hr or 1:12 swim
2 mph + 2 mph current ==> 0.60 hr or 36:00 swim
Thus the 1 mph swimmer is 1:36 faster with the 2 mph current vs the 2 mph swimmer who is only 36 min faster. With no current, the 2 mph swimmer emerges with a 1:12 lead on the 1 mph swimmer, vs only 12:00 with the 2 mph current. So, yes, the slower swimmer gains a huge amount more from the current. QED.
My swimming hasn’t really improved any since I started doing long course - just don’t invest enough time to make gains. So here are my times:
IMFL 2007: 1:03:37
IMCdA 2009: 1:08
IMNY 2012: 44:44 - yeah - down river 
Kona 2012: 1:12:49 - no wetsuit easy cruise
ChoCho 2014 - 48:18
So I’d say Chattanooga was 15-20min faster last year but that is all dependent on how much flow TVA is letting through so it’s all a guess for the future.
Race director promised to have minimum flow this year. I still expect some but don’t think it will help more than 5 minutes…
It’s a non-issue, really. Everyone will get the same boost.