i just started training with power and noticed that there is a huge difference between my output in watts on climbs vs flats. for a 10min effort on a steady climb, i'm at about 295W vs about 220W on the flats for the same time frame. for a 1hr effort the disparity is about the same... 250ish vs 200ish. at 66kg, i'm definitely better suited to climb, and i do enjoy climbing much more than hammering the flats, but is such a huge difference normal? are there physiological factors at play or is it mostly in my head? also which number should i use to base my threshold training or should i just two different numbers depending upon the terrain?

Some good stuff here.

https://autobus.cyclingnews.com/fitness/

All power is not equal, there is a relationship between power, force (torque) and cadence. If you have WKO 3.0 or Golden Cheetah you can view a quadrant analysis which displays a scatter of the force/cadence relationship and divides it up into quadrants of high/low force and high/low cadence. Climbing often ends up being a high force/low cadence situation, and that may just be what you are best physiologically adapted for currently. Also there is a big mental aspect, as it can be easier to motivate to work hard on a climb than on flats. It is very common for people to be able to put out more power on climbs but it is not universal.

Also, if you are standing you can "throw" your bodyweight around, as well as bring more muscles into play. If you were not aerobically limited then using more muscles allows you to utilize more of your aerobic capacity.

Although I'm sure there is a lot of "good stuff" there, none of it is remotely relevant to the question that was asked.

Many people, myself included, have noticed the same issue. And yes, it is "in your head": (a) we are used to riding at say 20 mph on the flats, so when we are climbing at 10 mph it feels slowand we try and ride faster and our power output increases as we try and ride closer to 20 mph, (b) when we try and ride 25 mph on the flats at the same wattage as climbing it seems fast and we tend to not push so hard. Also with experience we learn that riding 20% harder on the flats increases our speed much more than 20% harder on the flats because of wind drag increasing as the speed squared.

Learing to ride time trials on the flats is the best way to learn to push your self on the flats....but it take practice and effort

As I said above, there is a large mental aspect but there are physiological reasons for the differences. So it's not necessarily all "in your head"

This makes no sense.

Looks like a typo! Maybe it should be:

Also with experience we learn that riding 20% harder on the HILLS increases our speed much more than 20% harder on the FLATS because of wind drag increasing as the speed squared

And then, there is always the question "Just how are we measuring power?"
Not all meters are equally accurate under all conditions.

I've never ridden with a powermeter, so I have nothing to add, but I'm left wondering:
What happens if you try and ride at 295 watts on the flats for 10 minutes (matching your climbing cadence)? Do you get more tired than you are after a 10 minute climb?

Show me some love umd, jeez.

You? Why? Did you think that link was relevant?

Cadence is a lot of it. Power is a great tool, but so is a HRM. Can't know what the OP is talking about specifically without HR info. We do know from research that maximum power at maximum effort is produced at about 55 cadence. IOW, higher cadences produce higher HR at the same power. HR is the limiter, not power. Max power is the number we see at our limit, so a symptom, not a cause of that limit.

What I'm getting at is that doing an LT interval on the flat, most of us will pedal at 95-100 cadence, while doing the same interval on a climb, we might pedal sitting at a 75-80 cadence. So because of the lower cadence, we'll see more power on the climb at LT than on the flat. That said, I'm not sure why that is. We do tend to tuck when we go hard on the flat and sit up on a climb. That affects lung and heart volume. It would be interesting to hold one's climbing cadence and hands-on-bar-tops on the flat and see if the HR vs. power is the same as when climbing under those circumstances.

wut

Sorry guy, you'll just have to think about it for a while. You might also try what I suggested and report back. The 55 cadence thing is true.

References?

Aw c'mon - google is your friend. Read the study years ago. I'll take a look in my Favorites.

The reason no one pedals that slowly in practice is because your legs only last a few minutes at that cadence and full-on power.

Could he be confusing maximum efficiency which occurs around 55 rpm with maximum power which occurs at cadences of 120 rpm or higher (depending on fiber composition and training)? Of course there's no getting around missing that heart rate is a dependent variable in all this, i.e., it is a response to the load placed on the body, not a controlling factor.

And while I'm thinking about things for a while, I'm still trying to get my head around what possible connection there can be between maximum power (which occurs over periods of less than 10 seconds) and heart rate which takes many times as long to respond to the bodies demands.

You know what would be great? If we could make something like a rigid cage to surround the heart and lungs so that as we change position the space in the thorax wouldn't get distorted and compressed. Maybe we should work on that?

interesting responses... thanks to all. i did go out on another flat ride today and tried to push bigger gears with a much lower cadence and true to the points here the power numbers were slightly up, and i actually felt a little fresher than when i was trying to spin 95+rpm. however, it did feel strange because lower cadence goes against what most people will say is efficient. although i have read that many people like to train for power by pushing lower gears? perhaps i may incorporate some of that into my rides. or perhaps as umd suggested, right now my physiology is such that my muscular endurance is greater than my aerobic endurance? that wouldn't be surprising given my 20+ years of smoking!

regarding HR, i realize that extra data points help analyze things better, but i just hate wearing the damn thing b/c it feels so constricting.

and of course, as i have already discovered with my short time training with power, the most important thing is to not obsess about the numbers and enjoy the ride, slow or fast.

Here's a good recent primer and compedium of studies:
https://www.fims.org/default.asp?pageID=213202031

It's probable that the study I read years ago was done at a moderate power output, at least that's what this compendium intimates. The problem with all these studies is that the devil is in the details. I always try things myself to see if they work. So here we have some highly trained, fully wired cyclists. Have a go at it! I don't have a power meter, or I'd join you. Find a 10 minute smooth climb and try it at 55 cadence and LT, normal climbing cadence and LT, and 100 cadence and LT. Leave about 10 minutes of easy spinning between intervals. See what your power graphs look like and what the numbers are. Hopefully you all are accustomed to muscle tension intervals and have a fully developed pedal stroke.

That doesn't sound normal. It may be common to have a small improvement in hill climb power but 75W is way too much. What kind of power meter are you using?

Keep in mind he is only talking about 10 minute power here.

Basically, what you stated earlier as fact ("We do know from research that maximum power at maximum effort is produced at about 55 cadence") turns out to be incorrect, or at least unsupported. It's not clear why anyone would want to test out your hypothesis. It's unlikely to answer the original question.

He's not using a HRM, so it's very probable that he just isn't inclined to go that hard on the flat. It is much easier to go hard when climbing. One of the truisms of TTing is that concentration is everything.

That link had some good info on power related articles, that is why I posted it.

It also housed additional information which low & behold proves power in cycling isn't everything. The OP might have found the additional knowledge to be helpful.

To determine which cadence produces maximum power, there needs to be a perfect blend of force and velocity & finding the “sweet spot”, this can come at a range of different cadences. You can spin a gear at 160 rpm, but with no force, your not in the sweet spot. 55 rpm doesn't sound right neither.