New to the whole power meter thing. Noticed that my endurance wattage dropped some 20-30 watts (at least) when it was 102 degrees with humidity yesterday and the day before. I didn’t wear an HRM, but I was holding the same effort for sure. Which leads to my next interesting question… If your HR is the same but your watts are lower, does this mean that the whole counting calories formula hypothesized by Allen Lim (being 1/4 efficient) could actually be wrong in these situations. Could the weather change your body to be 1/5 efficient? Interesting to note, when I ride on a trainer I cannot get my power nearly as high as I can on the rode. I would say that there is actually a 50 watt differential for me. Is this normal? And are the same principles applied?
New to the whole power meter thing. Noticed that my endurance wattage dropped some 20-30 watts (at least) when it was 102 degrees with humidity yesterday and the day before. I didn’t wear an HRM, but I was holding the same effort for sure. Which leads to my next interesting question… If your HR is the same but your watts are lower, does this mean that the whole counting calories formula hypothesized by Allen Lim (being 1/4 efficient) could actually be wrong in these situations. Could the weather change your body to be 1/5 efficient? Interesting to note, when I ride on a trainer I cannot get my power nearly as high as I can on the rode. I would say that there is actually a 50 watt differential for me. Is this normal? And are the same principles applied?
Thanks,
Chris
Your body is most efficient at certain temperatures so if you are in a temperature zone you are not trained to then you are probably less efficient - I don’t have scientific data to back this off hand
I wouldn’t put too much stock in anything Mr. Lim has to say, maybe he is wrong, maybe he isn’t. You need to decide what you need to do.
Most people output significantly less on the trainer due to: inertia, cooling, motivation, etc there are some good articles on this if you search
I forget which masters National TT champ said this but Coggan has quoted the following numbers from him -
He lost roughly 3% of his FTP for every 10 degrees the heat index got above 60 degrees fahrenheit. So 102 degrees would see a loss of over 12%. Maybe a lot over depending on humidity.
I am no expert. What Dave Luscan is saying above makes perfect sense. I don’t know what the actual numbers are, but in reality the power output should drop with a rise in temperature due to the same reasons you cannot put out as much on the trainer due to heat, humidity, lack of cooling, loss of body fluids…I think it applies to cycling just like with running. No one is capable of putting the same performance half marathon at 60F and 85F, now factor in humidity…Daniels pace table have adjustment for temperature over 60F,where pace drops 3-4s/mi for every 5F rise in temp over 60F…I just cannot quantify it in cycling. I did notice that same 260W at 80F and 75% humidity take a lot more life out of me than at a lower temp, 260W being about 92% of my FTP. The difference is such for me that at 80F, 75% humidity I cannot run worth a …where at plain 70F, I can race oly pace after.
New to the whole power meter thing. Noticed that my endurance wattage dropped some 20-30 watts (at least) when it was 102 degrees with humidity yesterday and the day before. I didn’t wear an HRM, but I was holding the same effort for sure. Which leads to my next interesting question… If your HR is the same but your watts are lower, does this mean that the whole counting calories formula hypothesized by Allen Lim (being 1/4 efficient) could actually be wrong in these situations. Could the weather change your body to be 1/5 efficient? Interesting to note, when I ride on a trainer I cannot get my power nearly as high as I can on the rode. I would say that there is actually a 50 watt differential for me. Is this normal? And are the same principles applied?
Thanks,
Chris
Your body is most efficient at certain temperatures so if you are in a temperature zone you are not trained to then you are probably less efficient - I don’t have scientific data to back this off hand
I wouldn’t put too much stock in anything Mr. Lim has to say, maybe he is wrong, maybe he isn’t. You need to decide what you need to do.
Most people output significantly less on the trainer due to: inertia, cooling, motivation, etc there are some good articles on this if you search
Our bodies will put out more power and run faster at cooler temperatures. This effect is pretty much universal. Though it will vary person to person, I am pretty sure not too many athletes would have a higher power at 90 degrees compared to 60 degrees regardless of where they train or what they are used to.
If you are not putting stock in what Lim says in regards to the science of cycling, who can you put stock in? Lim bases his advice in science, which works for us due to the fact that in most ways we are more alike than different. Certainly in a physiological sense.
“You need to decide what you need to do” is based on the often repeated pseudo-science that we are all different. We ain’t.
The inertial loading theory is one guys idea and has been debunked a few times. The real effect going on indoors is AIRFLOW. So many people ride with no fans or only one small fan. You will literally be surrounded by a bubble of hot air in these situations. A sub 70 degree workout area with enough fans to simulate moderate gale conditions will erase almost all of the power differential indoors to outdoors. Proper music will usually take care of motivation. Inertia is bunk. Bigger flywheels feel better, but do nothing for wattage, unless feeling better improves your motivation, which could cetainly be the case for some.
Back to the OP, I would make sure of the calibration between your indoor and outdoor PM, or in the case they are the same, take a look at your airflow indoors. 50 watts is alot regardless of your FTP.
I will let someone else answer the calorie part of your question as this is not reeally something I am overly concerned with.
Definitely - As you train/race with power more, you will see the trend easily. Makes no diff in a race (everyone else has to deal with it), but occasionally (like recently) you might need to adjust your target interval watts a little.
Funny you wrote this today. I rode yesterday and kept thinking my pt was wrong. Most of the ride I was making plans to re-calibrate when I got home, I was easily 10% lower watts with my target HR. I didn’t realize how hot it was until I stopped moving at home, chalked the lower power up to heat and humidity. At least thats what I hope it was!
I forget which masters National TT champ said this but Coggan has quoted the following numbers from him -
He lost roughly 3% of his FTP for every 10 degrees the heat index got above 60 degrees fahrenheit. So 102 degrees would see a loss of over 12%. Maybe a lot over depending on humidity.
These numbers are in line with my experience.
Those numbers agree with my hot/humid SE VA experience. To the OP: if you perform frequent testing or monitor your power on long intervals during training, you shouldn’t neet to apply a correction factor to your FTP because you’ve tested/trained in a hot/humid environment already.
The 3%/10 degrees F degredation should be useful when traveling to a race in a markedly hotter/cooler climate or if race day has atypical weather.
Regarding inertial loading and indoor training, I can’t say whether or not there is scientific evidence as to the effect of inertial mass on sustainable power. I do prefer the feel of the 18 pound flywheel on my Kinetic pro trainer to running that trainer with just the 6 pounder. If nothing else, 18 pounds of rotating mass is closer to the conditions one experiences outdoors and specificity is a good thing right?
"Coggan has quoted the following numbers from him -
He lost roughly 3% of his FTP for every 10 degrees the heat index got above 60 degrees fahrenheit. So 102 degrees would see a loss of over 12%. Maybe a lot over depending on humidity."
Wouldn’t the amount of wattage lost depend in part on the course? If the course is flat, your average speed is higher and hence you should get more cooling effect from the wind. n=1: About a month ago, on a very warm and humid day, I managed my fastest metric century ever, while those who chose the hillier standard-century option seemed to suffer more from the heat. (They started before us, so I don’t think the difference can be attributed to a later time of day.) My average wattage was also pretty high (for me!) that day, although I haven’t had my powermeter long enough to have a lot of basis for comparison.
Right after I read those numbers on another board, I raced a time trial at which I theoretically could have paced at 330 watts if it was cool. It was 95 degrees and humid so I literally FORCED myself to ride 290 watts from the gun.
I beat a bunch of guys stronger than myself who I never came close to before. One 350+ watt fellow told me he limped across the line at 220 watts for the final 10 minutes. Those 290 watts for that 50 minutes felt EXACTLY like a 100% effort, as I’m sure about 330 would have felt at 60 degrees.
Something that hasn’t been mentioned is “where do my watts go?” Your body cools itself with the same fluid that it uses to provide oxygen to working muscles. So as we divert blood to the surface where it can exchange heat, there is less oxygen going to the working muscles. This is why skinny people deal with heat better. More surface area compared to mass. Surface area = cooling area.
Sure. Especially if we are talking 12 mph compared to 28 mph. The numbers quoted above are more of one guys rule of thumb, which I found useful for my typical time trial and triathlon speeds.
Our bodies will put out more power and run faster at cooler temperatures. This effect is pretty much universal. Though it will vary person to person, I am pretty sure not too many athletes would have a higher power at 90 degrees compared to 60 degrees regardless of where they train or what they are used to.
If you are not putting stock in what Lim says in regards to the science of cycling, who can you put stock in? Lim bases his advice in science, which works for us due to the fact that in most ways we are more alike than different. Certainly in a physiological sense.
“You need to decide what you need to do” is based on the often repeated pseudo-science that we are all different. We ain’t.
The inertial loading theory is one guys idea and has been debunked a few times. The real effect going on indoors is AIRFLOW. So many people ride with no fans or only one small fan. You will literally be surrounded by a bubble of hot air in these situations. A sub 70 degree workout area with enough fans to simulate moderate gale conditions will erase almost all of the power differential indoors to outdoors. Proper music will usually take care of motivation. Inertia is bunk. Bigger flywheels feel better, but do nothing for wattage, unless feeling better improves your motivation, which could cetainly be the case for some.
So let me get this straight. Something can very person to person but we are all the same so nothing should change person to person. Then you go on to restate what I said. You have added a lot to this discussion thank you
Our bodies will put out more power and run faster at cooler temperatures. This effect is pretty much universal. Though it will vary person to person, I am pretty sure not too many athletes would have a higher power at 90 degrees compared to 60 degrees regardless of where they train or what they are used to.
If you are not putting stock in what Lim says in regards to the science of cycling, who can you put stock in? Lim bases his advice in science, which works for us due to the fact that in most ways we are more alike than different. Certainly in a physiological sense.
“You need to decide what you need to do” is based on the often repeated pseudo-science that we are all different. We ain’t.
The inertial loading theory is one guys idea and has been debunked a few times. The real effect going on indoors is AIRFLOW. So many people ride with no fans or only one small fan. You will literally be surrounded by a bubble of hot air in these situations. A sub 70 degree workout area with enough fans to simulate moderate gale conditions will erase almost all of the power differential indoors to outdoors. Proper music will usually take care of motivation. Inertia is bunk. Bigger flywheels feel better, but do nothing for wattage, unless feeling better improves your motivation, which could cetainly be the case for some.
So let me get this straight. Something can very person to person but we are all the same so nothing should change person to person. Then you go on to restate what I said. You have added a lot to this discussion thank you
Sorry. Let me dumb it down for you:
Point #1 - It can vary from person to person, but this doesn’t change the fact that physiologically we are essentially the same. So listen to smart scientists, and don’t base things off the very small variability person to person, but rather the enormous similarities.
Point #2 - AIRFLOW is the issue for almost everyone. Motivation is far less of a factor once airflow is attended to. Inertia is a red herring.
I forget which masters National TT champ said this but Coggan has quoted the following numbers from him -
He lost roughly 3% of his FTP for every 10 degrees the heat index got above 60 degrees fahrenheit. So 102 degrees would see a loss of over 12%. Maybe a lot over depending on humidity.
These numbers are in line with my experience.
I don’t doubt that rider’s experience, but I think it simply points out that individuals’ responses to external stimuli are, well, individual… It’s also worth nothing that the rider mentioned above also told me that he has very little deterioration of power at altitude–which is atypical. So while we are all more similar than different, we are also different to a degree.
I took a quick look at my files, which are SRM stamped with temperature–and my own conclusion is that I have zero power drop off between 40 degrees and 92 degrees, with a pretty significant drop off above 95 degrees.
Lastly, my own experience is that of one who rarely sees extended periods of hot weather, but the available research out there seems to suggest that heat acclimatization reduces its effects. While you’re right that I doubt anyone is putting out more power in hotter weather, I think the drop in power is going to range from ‘inconsequential’ to ‘significant’.
So, in short, I doubt that the drop in power is all that formulaic, and I also doubt that it follows a linear progression for everyone.
For some real world numbers, I came from mid to late 20s celcius with an FTP around 380. It is now in the early 40s and I am pushing around 310. Heart rate goes through the roof very quickly. The first say, 10 minutes of a test is generally pretty good but goes down hill very quickly after that. Have reduced some training volume as a result of the heat though which would need to be accounted for. Tests have had to be over 20 minutes and extrapolated of late as 60 mins in the heat is BS.
Test of 1 with no checking by anyone else so is entirely possible it is rubbish due to differing protocols.
