I have been cycling now for about 6 years and have consistently noticed that I can sustain higher power output when I am going faster. My FTP is somewhere around 275w (3.2 W/kg - I’m 190lbs) and in normal conditions/speeds I can sustain tempo pace indefinitely at about 245 watts or so. But give me a tailwind or a fast group and that sustainable tempo pace jumps to around 270. On the other hand put me on gravel or in a headwind and that sustainable tempo pace drops to about 225. I’ve thought maybe this was just psychological (cuz fast is fun) but over time I am convinced it is real. Maybe a little hard to explain but at higher speeds I can simply feel that I’m not going into the red as easily. And maybe a key observation is that my pedal stroke feels different. Like I can feel my foot’s contact with the pedal carrying momentum all the way through the stroke. So, my question is: is this a function of my muscle fiber type composition? Or (as I suspect) a flaw in my pedal stroke and muscle recruitment that is most noticeable at slow speeds but goes away at higher speeds? Or something else entirely? And second questions: how/what do I train to get the same power and feel at lower speeds that I have at higher speeds.
Is your cadence similar in all conditions?
Higher cadence demands more from the cardiovascular point while lower cadence is more demanding on the muscles.
Most people tend to lower cadence when resistance goes up (gravel/uphill/headwind…) and then you’re using up muscle glycogen.
My cadence stays pretty locked in at around 85-90 rpm. So don’t think its that, but I’ll look at the data a bit closer.
You don’t mention the duration of holding the power for, before fatigue causes you to slow down, ease off.
I’d say these are outputs I can sustain for at least and hour. Probably more, but I don’t regularly have much reason to go at that pace for longer than that. If it helps, my power curve this season is 10m at 271w, 20m at 251, 60m at 236.
This is my cadence for a ride on Sunday that had sustained 20mph winds. Cadence was actually highest in the headwind section.
Robert, this is one of those questions that invites a great deal of discussion. Reminds me the chatting after motorpacing sessions.
I am not aware of any strong evidence in the literature on this topic, so I will answer from experience and observation. It would be worth taking a close look at the quadrant analysis from the activity you shared above. As an interesting exercise, if you’re willing, feel free to share the .fit file with us.
I think you’re right that there are both psychological and mechanical components involved. At higher speeds, even at the same cadence, there is generally more inertia in the system. This is easy to notice on a simple not-smart trainer: using different gear combinations, you can produce the same power at the same cadence using different trainer resistance, and the setup with the faster wheel spinning speed often feels easier.
My hypothesis is that this relates to the small fluctuations in wheel inertia, which become more pronounced at lower speeds. That likely affects torque application throughout the pedal stroke, torque peaks, and the contraction-relaxation cycle of the muscles from one revolution to the next. Remember, we’re talking about identical cadences here.
At higher speeds it is much easier to maintain continuity in the pedal stroke, preserve momentum, and apply torque smoothly and consistently. Combined with the higher cadences that often happens in those situations, this tends to support higher power output.
* This cannot be directly compared to climbing versus riding on the flat, because the constant resistance of a climb changes the issue entirely. In that context, the inertia advantage of riding on the flat turns against this whole idea. This may help explain why many riders can produce better power on climbs than on flat roads with a tailwind. Does anyone disagree?
Several things here really resonate with me and my experiences. First, it does feel like I am more resistant to small perturbations at high high speed. When cruising, if I hit a bump, get a little gust of crosswind, pause to make sure that car isn’t pulling out, I feel like I can just ride through it without it affecting me. At lower speeds it seems like this feels like I put a drag chute out. And mathematically, it makes sense because proportionately, a 1 mph decrease in speed is proportionally much greater when doing 15 mph compared to 25 mph.
Your observation about the trainer resistance is also on point. When riding indoors I almost always ride in the little ring to save wear on the big ring am astounded at how much less power I can put out for the same effort. Occasionally, the trainer can’t meet the resistance in the little ring so I have to shift it and I can put out about 20-25 more watts at tempo pace in the big ring.
And your point about riding up hills is something that confounded me and that I left out of the original post. Despite being a bigger rider, I am a strong climber especially on long climbs. As when going fast, when climbing I feel the pedal through my entire pedal stroke and feel like I am putting out very smooth power.
So I guess the similarity for me is be that on climbs and when going fast, I am facing an even resistance that I can push into with a smooth pedal stroke. On gravel or with a headwind, I am letting those small perturbations of terrain or gusts break my momentum. Big question: is this something I can train to overcome?
Wow, this reply easily makes it to my Top-3 replies ever on the forum.
I was thinking in the same direction with cadence/inertia/resistance/torque fluidity/etc. But I would have never been able to explain it the way you just did!
I’m completely with you on this. Unless someone comes with a scientific proof that it is related to something else.
There is also a lot more cooling at faster speeds. I can put out the same power at low and high speed, flat or climbing, low or high torque, but can last longer at high speed because it’s both fun to go fast and there is more evaporative cooling.
I don’t have any data on this topic at all, but I would imagine that the psychology of it is definitely at play here.
When you are having more fun and putting out less mental effort, it gives you more energy/effort to put into the pedals
@Robert_A_Smail , one important point that we forgot to ask: what happens to your heart rate in the scenarios you mentioned?
Heart rate is the same in both situations. Which does tell me I’m doing the same work for less power at the lower speeds. And this supports your earlier response.
My 2 cents: your power curve doesn’t tell that you indeed put an hour at 270, but matches closer to the one you put in gravel at 230.
Because of aforementioned inertia at speed, it’s possible that you don’t actually pedal at 270 full time, but are able to back off (coast or lower watts) without noticing it or losing any speed. If you did that in a headwind, gravel, etc, you’d notice immediately and bike would slow down.
The other element is adrenaline: at speed, perception of time slows down. What might seem like an hour of hammering might’ve been a 10 min effort before backing off.
The only way to test this is to set a lap timer and go on a windy ride. Time a 20 min segment downwind then turn around and time one upwind. Share the fit files here 
I really like this story as it proves there are so many different riders out there.
I had a fast look at what is the exact calculation when messuring power. Why? Because power output isn’t the same for everyone every time they cycle. Which brings us to components and measures of Watt.
If you have a standard power meter it is defined by the force on pedals x cadence.
If you are getting this right then it really doesn’t say alot about speed. We know this because going downhill at 60kph without moving your pedals gives you 0 watt output!
So to answer your question, it is most likely psychological.
Another question you could ask is what are you doing with those data points? Because in the end they are just numbers.
I strongly agree with the first part. The second part is close, but it’s backwards from my theory.
At higher speeds the torque becomes more un-even. There is a larger peak force output, but for a shorter duration of the pedal stroke. At slower speeds there is a lower peak force, but for a longer duration around the pedal stroke.
In other words, at higher speeds you have to put out a higher peak force, but also have more time for the muscles to recover around the rest of the pedal stroke when the force is lower.
If I focus on “pedaling circles” when I’m moving faster, my legs start to feel it, as if I was going up a hill. That tells me I need practice that more and smooth out my pedal stroke.
That makes sense! Good catch.
Would be a good ideia to look at peanut graphs or other torque metrics.
I experience the same phenomena. Give me a 1-2% downhill and for some reason I can maintain nearly 20% more power. I have always thought it’s mental because it’s “easier”, but trying to hold the same power uphill, my HR skyrockets.
I’m the opposite from the OP, my power suffers at higher speeds especially on slight downhills/tailwinds unless I specifically train in those conditions. I’m much better uphill or into a headwind and if it’s a very steady climb I can easily put out 20% more power for the same effort/HR than in a tailwind. My ideal climbing conditions are on steepish uphills with a tailwind, I suppose because it lets me pedal smoothly against no wind resistance. I always climb seated.
Does efficiency come into it? My efficiency is pretty terrible, as evidenced by my poor out-of-saddle performance compared with seated. Or maybe gravity for some people (like me) who need that extra force to push against to put out their best power, vs those people who can keep pushing right to the bottom of the pedal stroke on flat ground (like the OP).
Anyway it’s quite an interesting phenomenon and I’ve always been amazed at the variety in natural human ability in cycling. There’s always someone in the group who goes backwards when the road goes up (even if they aren’t overly heavy) and others who drop everyone in a tailwind.
@Robert_A_Smail - Just want to say that your descriptions in the OP and this post are very similar to my own experience! I have also wondered about this - although I have never been able to articulate it as nicely as you have here.
I think @Gabriel_Vargas’s explanation in terms of small fluctuations makes a lot of sense. Gravel, head-wind, and even a rough road surface all increase perceived effort, while tailwind, steady uphill, and a smooth road-surface all decrease perceived effort. No doubt there is a psychological component, but I think there really is less “wasted” effort in stabilizing and maintaining the pedal stroke when the counterforces are more consistent.