canklecat

Ah, thanks. I must have misunderstood another fellow's explanation of how his power meter worked. I didn't get that it measured effort regardless of external conditions such as wind or road conditions.

Seattle Forrest

Heart rate is only very loosely correlated with how many calories you're burning. I mean how many heart beats are there in a calorie?

A person running a long slow marathon in Z2 is going to burn a lot more calories than somebody watching a scary movie sitting on the couch.

For what it's worth, the only way to get a more precise estimate of your calorie burn on a bike than a power meter is a metabolic chamber. And the power meter doesn't know or care what your heart rate is. Just the amount of work you're doing, and the rate you're performing it at.

Seattle Forrest

There's a guy who posts here, @RChung, who came up with a method of using data from a power meter and speed sensor to "measure" your aerodynamic drag. You have to ride laps and not touch your brakes, because math. A power meter measures the rate at which you're doing work, 1 watt = 1 Joule per second. That's essentially the same thing as an objective measure of effort.

Most of them work by measuring how much something (hub, crank arm, pedal spindle, etc) deflects under load, and how often that load is placed. So your cadence times how much torque you're applying. You'll get the same number for the same effort no matter what the conditions are. But that number will get you a different speed depending on the conditions, which is why you can use them to back into an aero profile.

Mostly they're used for training though.

canklecat

I've found a couple of online calculators that guesstimate power output based on wind resistance/assistance and available data from Strava or other apps. Doesn't factor in road conditions, which vary too much to be guesstimated by online calculators.

Seems pretty close to accurate, or at least it matches the data for other folks I've ridden with who do use power meters, so wind and road conditions were the same. When those riders also happened to be my size and weight their power meter data was very close to the online calculators. But their bikes are a bit lighter, sub-20 lbs, while mine is closer to 25. Not sure how much difference that really makes. Ditto factors such a aero kit, helmets, etc. Not sure how significant that is compared with bike and rider weight. Probably gets into nths of a degree.

Somewhat helpful, especially when the data are used to negate the influence of tailwind and factor in headwind. Mostly confirms my hunch that on a good day I'm lucky to sustain 200 watts. Occasionally I can manage 300-400 for maybe a minute or so. And I loaf, a lot, between hard efforts -- like, 100 watts. Just estimates from online calculators. Might be interesting to try a cycling gym with actual power meters, but the only such place locally closed shop last year. I can't justify the expense of a power meter. The online calculator guesstimates are close enough.

I usually ignore my heart rate as a significant factor because until recently I was taking meds that strongly influenced my HR and BP. It'll take awhile for my metabolism to settle out to any sort of useful baseline. So far the main difference I've noticed is my HR settles down a bit more quickly from hard effort. Before changing meds my HR tended to stay above 100 for hours after finishing a ride or exercise. I haven't tried to recheck my maximum HR since last year -- back then it was 175. Considering my age (61) and health that still seems like a reasonable target.

wphamilton

I'm guessing that you're using perceived effort for which zone you're in? If so, I get the same thing outside when it's 40's and below compared to spring and summer weather. I feel like I'm riding "just as hard" either way, but it's taking a lot more in the colder weather and it's not just the thicker air, and heavier clothes. It seems like my body is just less efficient and that would translate to higher heart rate.

Could be lungs not doing as well in cold dry air, or capillaries not opened up as much or as quickly. Maybe other things as well, but I'm convinced it's a real thing.

MoAlpha

Doctrine has it that the gas exchange surfaces are so deep in the lung and so protected by the airways that they don't see much change in humidity or temperature as a result of environmental conditions. Part of this protection is reflex constriction of the bronchi (with reduced air flow) in response to cold. When this response is exaggerated in irritable bronchi, that's cold-induced asthma and is very common.

JasonD67

No, my HR monitor shows me what zone I'm in on my computer. It even shows you a little bar graph so you can see how much time you spend in each zone at the end of the ride.

For me, my legs just feel weaker in the cold. Hills that I zoom up in the summer are a struggle in the winter. I think my muscles just don't have as much available energy when it's cold. Can't wait for summer so I can compare HRs.

gregf83 

Do you ride the same number of hours/wk in the winter vs summer? Most riders ride more and have better fitness in the summer so hills feel easier.

JasonD67

I ride less outside in the winter...if it's cold (say <25F) or there is snow/ice on the ground I ride on my trainer. Plus, I've noticed I just don't have the same stamina in the cold as I do in the warm (again, I think this is related to the increased HR, you can only stay in Z3 and Z4 for so long), so my longest winter rides are maybe 1.5 hours. I CAN ride longer in the cold, but the physical toll just isn't worth it (I'm no professional).

My fitness level is down in the early spring when it warms up, so I definitely loose something over the winter.

wphamilton

If you're not relating perceived effort to the HR zone, I don't understand your OP. It looked to me like you're saying that the efforts are different for the HR zones inside vs outside, or that the HR zones are different for the same effort. Which both amount to the same thing.

Otherwise it would just be a case of you working harder when riding outside.

wphamilton

I hadn't thought that a lungful of air could warm up that quickly going through the bronchi, but I believe it. It does warm up and humidify just going through my scarf, after all, so that makes sense.

If you have constriction, does less air - lower oxygen - cause the HR to increase?

JasonD67

I ride "normally" outside in the cold: I'm in Z3 and Z4 all the time. Getting into Z4 just requires a short 2-3% grade climb.

I ride "hard" inside: I'm in Z2 and Z3 all the time. Getting into Z4 requires great effort i.e standing on the 53-13 at 100+RPM.

MoAlpha

rubiksoval

Gotcha. Couple of different kinds. Some measure power with strain gauges at the pedal, some at the crank, some at the hub. Keeps things honest.

Sy Reene

You forgot the Arofly method..

wphamilton

So there's a theory for OP then. The colder air outside may irritate the bronchial passageways, lowering the oxygen throughput to his lungs, which could cause an increase in heart rate. For the same effort on the bike, his heart rate is in a higher zone.

firebird854

Unless you have a power meter which you can use outside and inside to ensure you efforts are the same I wouldn't jump to such conclusions.

JasonD67

I don't have a power meter, but there is no doubt in my mind my power is way down in the cold. There's a small 3% hill w/in a mile of my house. When I climb it in the winter I can just feel my legs and lungs giving out as I climb (hitting Z4 in the process - my HR hit 180 last time I did it), even though I left home less than 5 minutes before.

First time I stand on the 53-13 w/in 5 minutes on the trainer, I feel I can go on forever (wish I could). The difference in the feeling in my legs in marked.

Voodoo76

Not enough warmup, when you are cold your body is moving blood to the core so you need a little more movement to counteract that. Try a 15 to 20 min loop at a moderate effort then hit the hill.