dsotm

Do colder temperatures affect how much energy your body puts out? Say if you did two identical rides, one at 70 degrees and one at 30, would you burn the same amount of energy? If so, how much of a difference would there be?

Busta Quad

Colder ambient temps (and wind chill) require your body to expend energy to keep your core temp at minimum levels. The answers to your question are "yes, no". How much of a difference is (probably) complicated. Nature is largely nonlinear.

dsotm

I would expect it vary, not only with temperature, but with wind speed, precip, and how much clothing your are wearing. I'm just trying to figure out if I need to each more (and how much more) after cold weather rides to recover fully. Thanks for the input.

bodaciousguy

Not only do you burn more energy but I think the cold is harsher on your body especially if you're like me and your body is naturally better in the heat.

Snuffleupagus

Hotter or colder, it requires more energy than it would in say 60ish degree weather.

For fun, read about homeostasis: https://www.biology-online.org/4/1_ph...omeostasis.htm

Basically, your body wants to be comfy. If you want it to do work when it's uncomfy, then it's going to burn more energy.

waterrockets 

Lim's recent interview referred to studies of people being able to set endurance records in freezing temps. As long as you're not cold enough to actually be "cold" (like shivering), then it's more efficient to be in the cold when you're exercising.

The quick summary from that portion of the interview was that if you're cruising around at 400W, you're producing another 1200W of heat. Your body consumes a lot of energy moving blood around to cool that heat. If it cools easier (like in the cold) then that's more efficient.

dobovedo

I've heard that for running, the 'centerline' of efficiency is about 50 degrees. It takes more energy moving outward in both directions, warmer and colder, and in roughly equal measures. But this can be minimized to the cold side by making the body more "comfy" with additional clothing.

More than the difference in homeostasis, and because of the higher speeds of cycling compared to running, air density plays a roll in determining how much energy (power) is required to maintain the same speed. Colder air is more dense, and requires more energy to overcome resistance.

An example: All other things being equal (zero wind/slope), I can ride about 20mph at 200 watts in a semi-aero position at 80 degrees. To do the same at 30 degrees takes roughly 20 more watts. Put another way, if I rode at the same 200 watts, I'd drop down in 19.4mph in 30 degrees.

BTW, these are software based calculations, not observable data taken off a power meter. Although the numbers are estimated, the reality is it does take more energy to ride in the cold. You can also add in the weight and increased drag of bulkier clothing. As well as some degree of restriction in movement. Heck, there's even a minor rotational weight factor in pedaling while wearing heavy booties!

Some of these factors may be small, but taken as a whole, they add up.

dsotm

Ok, this makes sense, The only place where I am typically cold, even down to 20 or so, is my legs. Consequently, I am probably not burning more energy there. However, the extra layers and more dense air probably end up adding 30-40 watts to the energy required. It seemed to me as if I was not recovering enough, that may be why. That's a 20% (very significant) increase.