If it's 40 degrees, I'm still training outside. That's comfy once you get the blood flowing and have the right gloves on. Especially for hard sessions and tempo runs. Base pace can be a little chilly. Since I live in FL, indoor training is mostly for either 1) weather that's too hot; or 2) schedule.

I recall a runner's chart I used to have lying around somewhere that showed the "ideal" race temp for long distances as 55 degrees. It had projected performance drop offs in 5-10 deg increments in either direction. If I remember right, though, it was more related to overheating than actual effort.

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This was bike related, for me. But, you're right.

I've been running on the side a little bit this off season. Maybe 1 to 2 hours a week.

I notice a huge change in pace from the 40 degree winter days to the "abnormal" days we get each winter that get up to 70 or 75.

I just figure you can impart a touch more stress without much drawbacks at a cooler temp. Or a higher density in general.

Isn't 200 watts for an hour outside at 40°F the same effort as 200 watts for an hour inside at 75°F?

I believe the OP's point is that the higher air density would allow for higher power output.

^^^----This.

Now, if you can do 220 outside and only 200 inside (or vice-versa)...then one might consider the benefits of a particular environment.

That said, my joints begin to stiffen up from the wind-chill below 40. So, last Sunday I rode on the trainer outside (at 35F) on my deck overlooking the pool and back forest. It was 2x20 day, and I ended up shirtless. :-)

That's a good point

The difference between a 40F day and a 80F is about 8% (assuming 32F dewpoint - very dry)

That would be similar to training at about 2000 feet lower in elevation.

I don't think that would have a significant effect on training

Edit: If you want to download this sheet you can play with the fields in yellow

https://docs.google.com/...1wY/edit?usp=sharing

I meant to ask the OP if that's what he meant, but forgot to. Nevertheless, he specifically asked:



Given the part in bold, I don't think there is any substantive different in the two scenarios.

I don't think the limiting factor in is the lungs ability to take in air but rather the ability of the blood to transport the oxygen absorbed from it. Thus the efforts of cheats to artificially increase this ability using EPO and transfusions.

So, it seems you're suggesting maximising power during training by maximising available oxygen via increased air density. If you can in fact produce more power when the air density is higher, fair enough - But can you?
Bear in mind, many people can produce more power outdoors than on a trainer for other reasons, such as better, cooling or better motivation. That doesn't seem to translate into many people arguing that you get a better quality session outdoors. Your suggestion seems to be equivalent, no?

I meant duration, not intensity. If you'd do 6 hours a week indoors, you'd do it out in the cold instead. But, not adjusting intensity to the extent you alter the system/zone or whatever you want to call it.

I flubbed that one. So, in the colder weather you'd bump your 4 hour base miles power from 150w to 165w or something. And so forth.

Runners, in reading stuff here and on the ever reliable internet, seem to target a good mix of temperature for PB's and records. Usually cooler weather.

So, if you're training an aerobic zone.......the max in that zone could in theory be lifted?

Power production capacity changes by roughly 1% per 1000 ft of change in altitude. The effect gets worse at higher altitudes (eg, 10,000 ft). So, assuming the figure above is correct that we are talking about a density change equivalent to 2000 ft of altitude (I didn't verify), you could expect ~2% increase in FTP and the various training zones in cold temps versus warm (also assuming we aren't talking about a mountain town). That's a change from 150 to 153 watts in your hypothetical scenario. Unless you have really big fans in your pain cave, the cooling effect is likely greater than the O2 content effect.

Running is different, because the PB effect in the cold is due to heat extraction not O2 availability. But, its kind of complicated because heat acclimation includes an increase in blood volume which can cause an increase in VO2max. So, training in the heat and racing in the cold has something of a compounded effect. Its still not that simple, because training in the heat all the time means that you are training slower...so, there's no free lunch unless you mix environments to maximize heat acclimation and training paces for "speed work".

Thanks.

I'm not that well versed in this stuff, and also not elite whatsoever in sport. But, if on top of maximizing my time I can maximize my environment.....all the better.

That's a good point on running with heat dissipation and training "hot" and the VO2 and blood volume.

I guess that's what interests me about the topic. Trying things out to maximize your efforts.

I wonder if the density change for cold air would be same, more, or less than shutting the door on a "pain cave" room and putting a towel on the gap and having the hvac on recirc pressurizing the room. Still run your cooling fans on you, but have the hvac do what you normally don't want........pressurize the room.

Your house is designed to operate at neutral to negative pressure to prevent losing inside air to out. I guess it's harder to draw air in than push it out.

I don't really understand any of this stuff all that well as it pertains to performing at different altitudes (or how that can relate to performing at different temperatures). The questions I have are:

Is air density the difference between performing at sea level and 10k feet?

If so, at what point does air density become a performance limiter?
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WRT the latter question, I guess I assume that if if air density is the limiter at 10k feet, it is because you inhale less oxygen per breath. At sea level, even at VO2 max, you don't even use all the oxygen you inhale. You are limited by what your body can uptake, not the oxygen in each breath. If the oxygen in each breath became low enough, it seems to me that the oxygen per breath would be the limiter, even though your body could uptake more if it were there. It seems like there would be a point where the air density is low enough that the oxygen per breath becomes a limiter instead of your ability to uptake more oxygen. That point may also be intensity specific (do you need high air density when operating at 50% of VO2 Max?). So, in considering your initial question, I wonder if the difference in air density in your basement low enough that it is limiting your performance.

Anyway, my whole train of thought could be way off here. If so, hopefully someone will correct me and I can learn something about air density and performance at altitude.

Apparently it is a thing:
https://www.bicycling.com/training/a20014286/how-cold-weather-might-supercharge-your-workout/


Also, if the aerobic base is based on something 10 to 15w higher........that HAS to be good, right?


Particularly if you cross train running with biking in the colder months. I'd imagine a runner could really optimize or get some gains.

Just my 2 cents but my best triathlons down south in the heat were in the spring off a winter of XC ski racing and training in minus 5 to minus 20C temps at sea level with a lot of really high barometric pressure days. For sure, this allows for more mechanical force per stroke (regardless of sport), given the higher amount of oxygen AND there is no limitation on overheating when training in those really cold conditions. It's a real win win for the high end intervals and TT type workouts. Coupled that with indoor training and treadmill workouts of heat acclimitization and it was the best of both worlds.

High intensity training in the cold under high barometric pressure to me seems like a no brainer for training gains.....it's the opposite end of training to super high altitude in the heat. In the latter scenario, mechanical forces are low and the heat means the mechanical forces are even lower....hopefully the counter to that if you training in Flagstaff (or something like that) in August is that you're getting some major blood plasma expansion due to heat and you're getting a hematocrit bump due to the altitude more than offsetting the limiations form low workload.

In an ideal world, I think you would train at sea level in really cold temps for the super high intensity stuff, you'd train at sea level on the trainer for your 3 weeks of heat trainining too for those adaptation workouts before a heat race (while still doing the cold intensity workouts for workload purposes) and you'd live up at 8000 feet outside of your workouts.

Most houses are not going to do very well at maintaining any worthwhile pressurisation so it may not be very realistic to attempt to raise air density that way.
You could of course just open the window for a while and train in the cold.

I don't know if colder air is necessarily denser. I would think it would be a combination of temperature, humidity and air pressure

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"What's your claim?" - Ben Gravy
"Your best work is the work you're excited about" - Rick Rubin

Usually here, in NC, my reason to not train outside isn't cold........but rain. Don't feel like bashing around Raleigh in rainy low vis scenarios. Also means having to power wash myself and bike if going to Umstead for it.

I could toss the trainer onto our covered screened in porch outside for some fun.

For sure though, I have done and do-do some harder workouts when cold out. Nowhere near as cold as the skiing folks though. That's cold!

Also, when I do plan to do TT/VO2 work.....I definitely drink up on the beet root. Perhaps placebo, but the HR versus amount of legs of fire feeling tends to change.

Colder air IS necessarily denser when composition and pressure are the same.

True. But, he's not really asking an air DENSITY question. He's really asking about the moles of o2 per liter of air. That doesn't change enough locally to matter...becsuee the performance impact of o2 content is only a couple percentage points for major swings in local atmospheric conditions. JFT, and do intense workouts with adequate cooling.

Agreed, I don't see much point in worrying over this one. There are far better ways to use the time than trying to contrive air pressures and densities in case there might be a tiny benefit somewhere. I suspect it'll do your training considerably more harm than good.