TimbukTOO Team Room

[mathineer]

***Humidity makes a significant difference in rowing difficulty***

Today I rowed my typical 10k at a moderate pace(2:14.5). BUT it felt like it was at a more difficult pace. The only difference being that last night I ate a chicken quasadilla from taco bell and this morning the humidity was at 99%. Its seems like my desert rows were much easier when compared. Maybe I'm just feeling fatigued from the quasadilla OR my revelation is indeed a fact. If the air is denser, heavier, and more viscous I must be correct. Right?

--- Mathineer are you good at dynamic wind load calculations? This humidity thing has me stumped.

Where are the math/physics nerds when you need them?

tick-tock.....tick-tock.....tick-tock....

Inquisitive minds want to know,

TMike

I'm not sure exactly how the C2 self calibrates, but it is supposed to compensate for the damper setting and might allow for air density as well. I think it more likely that the humidity affected YOU. At 99% humidity, it is much more difficult for the body to cool itself, and that would significantly affect the perceived level of effort.

[TMike]

I'm not sure exactly how the C2 self calibrates, but it is supposed to compensate for the damper setting and might allow for air density as well. I think it more likely that the humidity affected YOU. At 99% humidity, it is much more difficult for the body to cool itself, and that would significantly affect the perceived level of effort.

...the C2 self calibrates, but it is supposed to compensate for the damper setting and might allow for air density as well...

I have always wondered about that. How in the world can it do that when there is only one sensor on the flywheel? With just a simple on/off pulse sensor and no air flow sensor or torque sensor I don't see how its possible for the computer to make those adjustments.

...At 99% humidity, it is much more difficult for the body to cool itself,

Ah-Hah! ---> You might be on to something there. I do recall that on the hot sunny days the rowing was much more difficult. Oh well, C'est la Vie.

Thanks for the feedback,
TMike

[ronmardix]

***Humidity makes a significant difference in rowing difficulty***

Today I rowed my typical 10k at a moderate pace(2:14.5). BUT it felt like it was at a more difficult pace. The only difference being that last night I ate a chicken quasadilla from taco bell and this morning the humidity was at 99%. Its seems like my desert rows were much easier when compared. Maybe I'm just feeling fatigued from the quasadilla OR my revelation is indeed a fact. If the air is denser, heavier, and more viscous I must be correct. Right?

--- Mathineer are you good at dynamic wind load calculations? This humidity thing has me stumped.

Where are the math/physics nerds when you need them?

tick-tock.....tick-tock.....tick-tock....

Inquisitive minds want to know,

TMike

The monitor measures how quickly the flywheel slows down between strokes (drag factor) and uses that information with the current speed of the flywheel to calculate work and speed/distance.

Things like elevation, temperature, and dust all come into play. I hadn't thought about humidity before, but it seems to me that the more moisture is in the air, the more the flywheel would slow down between strokes (higher drag factor). If that's the case, then a session in higher humidity would in fact feel more difficult.

The way to deal with it is to always set the damper to give a consistant drag factor; this would mean a different damper setting in the desert than in a region with higher humidity or at a higher elevation.

[damselfly]

Sorry kids, no time for witticisms, just the facts today...

Welcome to returning member Allen Hammer!! Glad to have you back in the boat!! 10 of 53 members (19%) logged 405,823 total meters Friday!

Milestones achieved:
David hit 3.9M, Jim hit 2.2M, Allen hit 250K!!

Approaching milestones:
Kyle is nearing 2.5M (-13,411m), Adam is approaching 1.3M (-44,619m), Yisroel is heading for 1.2M (-27,324m), Allen is closing on 300K (-22,300m), and Warren is on the heels of 250K (-16,530m)


Posted Meters:
Allen H - 277,700 Welcome back!
David W - 50,002 Flexing big!
Jim C - 18,000 Playing with new distances...
Kyle J - 15,026 Nice!
Yisroel H - 14,621 Off to shore...
Adam M - 8,000 Right on!
Kevin K - 7,000 Streak is alive!
Gary G - 6,336 Sweet!
Warren F - 5,000 Back in the groove
Nancy W - 4,138 Cool!

[CONLEJM]

I hadn't thought about humidity before, but it seems to me that the more moisture is in the air, the more the flywheel would slow down between strokes (higher drag factor). If that's the case, then a session in higher humidity would in fact feel more difficult.

Hard to believe, but moist air is less dense than dry air. I remember this from high school physics, that a baseball will travel farther in humid air than in dry air. Here in New England, a high pressure system results in cooler dry air, while a low pressure system results in warmer humid air.

http://theweatherprediction.com/habyhin ... index.html

[TMike]

Thanks for the explanation Ron -- that had me baffled. Ha ha...

Hard to believe, but moist air is less dense than dry air. I remember this from high school physics, that a baseball will travel farther in humid air than in dry air. Here in New England, a high pressure system results in cooler dry air, while a low pressure system results in warmer humid air.

http://theweatherprediction.com/habyhin ... index.html

But wait....I think there needs to be some serious explanation with that -- you are saying that a quart jar filled with humid air would be lighter than a quart jar filled with dry air?

The world is crazier than I ever imagined!


On another note...

Has anyone experimented with Sprint 8/ peak 8 conditioning -- I just did it, and almost died! I think i'm going to add it to my 10k days for that extra metabolism boost.

On a weird note --- I just weighed myself --- Not good. Whats funny is that I AM skinnier than 6 weeks ago when I started, but i weigh the same -- Is it possible to gain that much muscle? I know I have lost 2 inches in my waist. Shorts are falling off, pants that i couldn't even button fit me now, ---humid air is lighter than dry, cats and dogs are living together, I'm skinnier but haven't lost a pound, its mass hysteria, its all chaos!!! What in the world is going on?!?!?

TMike

[damselfly]

Mike, it's probably a combination of fat loss, some muscle gain, and tighter musculature. Any way you look at it though, it's good stuff. Keep up the great work!!

Some won'drous geeky physics goodness on air density affected by humidity
here.

I can also say from experience that weight can change drastically from day to day due to water fluctuation. I weigh myself daily and watch the trend. You need more data points!!

[ronmardix]

On a weird note --- I just weighed myself --- Not good. Whats funny is that I AM skinnier than 6 weeks ago when I started, but i weigh the same -- Is it possible to gain that much muscle? I know I have lost 2 inches in my waist. Shorts are falling off, pants that i couldn't even button fit me now, ---humid air is lighter than dry, cats and dogs are living together, I'm skinnier but haven't lost a pound, its mass hysteria, its all chaos!!! What in the world is going on?!?!?

Weight is not a proper metric to check on your physical condition. It's used by the general population because it's easy to measure. Athletes and people who exercise regularly can't really use weight to measure improvement in physical conditioning - there are too many other factors. A better metric is fat percentage, which isn't simple to measure. The bottom line is that if you are losing fat - like 2 inches in your waist - than you are getting in better shape.

A tape measure may be a better friend to you than a scale.

[CONLEJM]

But wait....I think there needs to be some serious explanation with that -- you are saying that a quart jar filled with humid air would be lighter than a quart jar filled with dry air?

Hi Mike: the short answer to your question is yes. The long answer is found in the link I had provided:

The amount of water vapor in the air also effects the density. Water vapor is a relatively light gas when compared to diatomic Oxygen and diatomic Nitrogen. Thus, when water vapor increases, the amount of Oxygen and Nitrogen decrease per unit volume and thus density decreases because mass is decreasing.

Also, I experienced the same weight-loss conundrum as you when I started rowing. Keep at it, the results will come in time. I've lost 30 lbs since I started rowing and eating better.

Keep up the great work!

[ronmardix]

Thus, when water vapor increases, the amount of Oxygen and Nitrogen decrease per unit volume

I imagine that this is why it's so difficult to get enough oxygen into the lungs during intense exercise when it's very humid.

[TMike]

Thanks for all the feedback. Teamwork in action!

FYI- Here is a GREAT link (from the forum Lisa sent me to) on density and drag of humid vs dry air using baseball as an example. It covers all the bases. Ha Ha!

http://www.exploratorium.edu/learning_s ... ept97.html



OK, knowing what we know ---> And contrary to the old 40's detective movies, cool dry air is more like pea soup than hot humid air. Given this fact, the only explanation for me "feeling" that desert rowing was easier was because the dry air simply allowed my body to cool more efficiently. Hah! Mathineer got it right off the bat. ---> Not so fast there bub --> That only holds true for lower elevations like at Snaggletooth rock outside of Needles,CA (983 ft)

...As you move to higher altitudes, air pressure decreases significantly, about 3 percent for every 1000 feet of elevation. So a moving baseball experiences about 15 percent less drag at the 5000 foot elevation of Denver's "Mile High" stadium than at a sea-level stadium like Boston's Fenway Park.

-->If we take a look at my Reno,NV row my elevation was at 4400 feet. It was cool and dry, but high elevation. Same for Two Guns,AZ at 5,420 feet., And the same for Lordsburg,NM at 4,250 ft. In the end, the cool dry air helped cool my body, but the increase in drag was negated by my elevation at Reno, Two Guns, and Lordsburg. Some folks might say that it was easier after all, at least in some sense. Given equal damper settings there would be less tension on the chain --- but more strokes should be required based on the computers drag calculations, I think. ---->Max damper settings were used at all locations.(Max damper = open all the way)




Examples of a baseballs flight at a fixed angle(55degrees) and velocity of ball leaving bat(165 ft/sec).

401 feet --- standard temp and pressure
799 feet --- in a vacuum
441 feet --- -10% air density(hot and humid)
421 feet --- -5% air density (hot and humid)
381 feet --- +5% air density (cold and dry)
361 feet --- +10% air density (cold and dry)

[damselfly]

And another new body in the TimBukTOO boat! Welcome Vince Miller!! Grab an oar, find a seat, and get comfy. It's a fun boat! Meanwhile, a gorgeous and geeky 9 of 54 members (17%) logged 136,357 total meters Saturday!

Milestones achieved:
Kyle crested 2.5M, and Aditya vanquished 350K!! (There, that gives Izzz a few more verbs to chew on.)

Approaching milestones:
Andy and Adam are teaming up for the assault on 1.3M (-11,502m and -27,119m), Warren is blasting towards 250K (-13,419m), and Vince is nearing 15K (-2,600m). Row like Steve Prefontaine ran!!

This week's frequent rowers (Sat 10/27 through Fri 11/2):
Kevin K - 7
Adam M, Jim C & Warren F - 6
Andy I & Kyle J - 5
Mark E, Matthew R & Mike M - 4

Posted Meters:
Aditya P - 42,195 Loves those long rows!
Kyle J - 18,411 Huge rows all week!
Adam M - 17,500 Found some extra time for a long one!
Gary G - 15,235 Everyone's stretching it out today!
Andy I - 12,427 Sweet!!
Vince M - 12,400 Welcome aboard!
Mike M - 10,000 To fume or not to fume, that is the question...
Kevin K - 5,078 Another day, another row!
Warren F - 3,111 Nice!!

[Quatroux]

New members! Welcome aboard. Glad to have you.
I registered for the local CRASH-B satellite this week. I really have no idea if I'll be sub-7 by then. I've made great progress, but February will be here soon.

[The Blacksmith]

Just did a 5k personal best 20:29.6.-and that's after doing over 20k yesterday. I figure that's not too bad for a paunchy middle aged guy

[CONLEJM]

Congratulations, Mark! It's great to hear about your progress. Keep up the great work!

Andy, I hope you break sub-7 in the next few months. Lots of progress can be made in three months, so I am wishing you all the best.

Hearing about other people's progress is one of my favorite aspects of this Concept 2 website.