Power uphill vs. down...
 

Recently, a few people were discussing this on the wattage forum, but I don't feel that any conclusive answers came out of it.

Basically, why is it so much easier to create watts on an uphill? Is it the lower cadence (which, suits me better)? Is it the ability to engage the hamstrings more effectively in that lower cadence? Am I just lacking high cadence training? Is it the fact that on a downhill your power with each pedal stroke needs to increase within that pedal stroke to keep that wattage up because the resistance is, in effect, going away from you (as your speed increases)? Where as on an uphill, you're not accelerating speed-wise, so your pedal strokes can be met by an equal amount of gravity?

I think it's safe to say that I am more strength oriented, and less cardio-fit (genetically, not just from a training or lack of standpoint), but I'm not sure if that plays a role.

This question came up for me as I'm trying to do 5x5 minute intervals at a set wattage. When doing 6x3's at that wattage two weeks ago, I'm not at my limit (although it hurts). However, now that I'm playing with my upper boundaries, if I hit ANY downhill or whatever in that 5 minute segment, and attempt to maintain my wattage, the pain and cardio taxing increase past my limit - I'm screwed. By set #4 today, I was toast.

I'm aware that there are probably drills I can do to increase efficiency at higher cadences, but my gut tells me that there is something else going on here. It's related to why WaterRockets does his WR Intervals (or just the 1 minute test) on an uphill. Why?

Gravity?

Do you think it's that simple? If I can upshift until I'm out of gears, why would it matter? Air resistance is actually welcomed at this point, as it should give me a terminal velocity (short of spinning out in my 53x12).

Would an airplane that is putting out 20,000 pounds of thrust be exerting any more g-forces on it's occupants (take away air resistance, just for a moment) if it's headed upwards at 35 degrees or downwards at 35 degrees?

Maybe it is that simple, I just don't understand why. Maybe I'm one of the few who actually experiences this. It's the power under acceleration, I guess, that is the culprit? Ugh.:twitchy:

going uphill offers a consistent resistance - gravity and rolling resistance don't change much unless the grade does. You can get into a rhythm and evenly put out power.

on flats or downhill, the majority of the resistance is from the air. Winds, even on a calm day are variable, meaning your resistance is always changing. It seems much harder to maintain a certain power because it really is hard without constant resistance.

don't believe me? hop on a trainer. With just a bit of practice, you can hold +/- 5w with ease

No! I believe you, no need to torture myself on a trainer right now, but that makes sense. Just amazing the difference that it makes and how much more painful it is to maintain a wattage on a downhill! :cry:

Thanks for the respones. :thumb:

crank inertia. search for it on the wattage board. varies by individual.

only the straightest and slightest of declines are "consistent." Usually going downhill you have to brake around turns (or not pedal anyway). You then accelerate out of the turns. Then it gets steeper and you speed up. Then it levels out and it's really hard to maintain that 38mph, then,then,then,

Forget holding a consistent wattage -- try to hold a consistent speed. It's hard enough when going 30+ for awhile.

Also you tend to spin faster going downhill. Most people aren't as smooth at 120rpms as they are at 80rpms. That might make it tougher to generate the same wattage, but it IS possible. I find that spin-up exercises up to 200rpms+ will help make you smooth enough so that it's just as easy to generate the same power regardless of RPM. However, muscle-fatigue sets in faster at 80rpms and I can't hold that wattage for as long.

Will do. Thank you.

kudude, that makes sense, just trying to figure out the physiology behind it too.

My strength now makes it easier (but not easy) for me to maintain wattage at a lower cadence. If I up my cadence too much, my cardio is a bigger limiter. So, what you're saying makes sense.

Also, more importantly perhaps, is my inability to even spin up to 200 rpm. I need to find some drills to do to help that. Interestingly, I've raised my saddle a bit in the last two weeks (mm's - not much but very noticeable). I would think that that would help my ability to spin - but I haven't found it to make high cadences easy. Am I wrong in that assumption about saddle height?

Anyway, thanks for the responses! :beer:

Doubt it. I'm good for an extra 20-30 watts uphill over longer distances. I'd always attributed it to better muscle positioning, and constant feedback of power output (you slow down much more noticeably).

Raising your saddle disables your ability to spin. You can spin faster if you lower your saddle a couple of mm.

if you're in the correct range for saddle height, a lower saddle will facilitate faster cadences.

I recently lowered my saddle by about 1cm, and my cruising cadence immediately jumped from ~90-92rpm to ~98-100rpm. I think you've got it backwards. (Though the lower saddle doesn't make it any easier (or harder) to spin smoothly above 125 or so, which is about my (pathetic) limit.)

It really depends upon where your saddle-height was to begin with. Optimally on my track-bike I have saddle so that there's 10mm of gap between my heel and the pedal (with leg-straight and pedal furthest distance from saddle). On my road-bike, there's a 5mm gap between heel and pedal.

So in your case, if you were too low to begin with, then raising it would help. If you were too high, then lowering it helps. But more importantly, it's pedaling-technique and form that really determins spin smoothness. One-legged exercises helps you find the dead spots and trains the brain/muscle memory cycle to apply force more evenly around the circle.

What happens with A LOT of people is that there's a dead-spot on their pedal-stroke and it requires force from the opposite leg to push up the other side. This is wasted energy that could've gone into pushing the bike down the road instead. If you have HRM and wattage meter, you'll find that by concentrating on your pedal-stroke to be smooth and activate the muscles to get through the dead-spot smoother, you'll find that speed & wattage will go up while maintaining the same HR.

A lot of people just have slow feet. I dont work with a power meter but think you all may be on to something, ability to produce power at higher rpm. Do your intervals at same speed but smaller gear.

It is all in your head.

Mentally we are used to riding about 20 mph on the flats, at least I am, when we are clibing at 8 or 10 mph, we are striving to ride at some pace closer to our normal speed and push our selves harder....and for the more knowledgeable rider, they know you will gain more time in a time trial by pedaling at a higher wattage on a climb than pedaling at the same higher wattage on a downhill.

Unless, of course, you happen to be riding where there's gravity. Then the force to raise the upward moving leg is provided by the weight of the downward moving one. The net result is it takes no muscular force to raise the leg.

+1, at least from my experience.

I find that I inadvertently ride much harder going down hill, but in bursts. The steady freddy nice resistance of a climb is much better for riding near threshold. A trainer is ideal, and I can maintain a pretty narrow power range while pedaling at 105-120 rpm, sometimes as little as a 1w variance but normally a +/- 10w range.

cdr

Wow, that's a lot of great feedback. I greatly appreciate all the responses.

I think that's probably one of the best phrases that I've read to describe the feeling of uphill vs. down at the same wattage.

You're right, I do have it backwards. And our limits are about the same!

Hey Danno. I'm not familiar with track riding, but from the advice of raised vs lower saddle, since your saddle is higher for track - I guess power is an emphasis there? (I know that track riders turn wicked rpm's too - IIRC). So for road, which side should I err on? If I create more power vs. the average rider, should I raise my saddle and set up my bike based on that strength?

Or, to put it a different way, if my strength is pedal force and not cardio capability, what side should I be erring on for the road saddle setup - low or high? Cater to my strength, or compensate for my weakness? With force as an asset, am I going down the wrong road by worrying about cadence/rpm? (I know I need to worry about it somewhat, just trying to put it into context w/ overall training).

Lastly, how much one legged drills should I incorporate if cadence/dead spots are a limiter?

Thanks, CDR. I do the same. However, I just don't know how other riders maintain power in longer intervals with the hills we have here in CT. I figure if you're riding for 5 minutes something will likely change incline-wise. Good for training, I guess.

I've been trying to do some steady wattage on rolling terrain. It's hard to find 20-30 minutes of uninterrupted road, even taking right turns etc, and I live in a really bucolic part of CT (someone shot a bear in his backyard a couple days ago in town). When I did some time trial efforts, I did it on a road that rose steadily for 15 minutes and then went shooting up for a lot of the next 30 minutes. I tried to make the easy wattage stay over 200 and the hard bits would end up at 280-400 automatically (hills), going up to 600 or so if I didn't pay attention and tried to accelerate a bit. I'd average about 240-ish, heartrate consistently at about 165 bpm.

I had to turn around one day when it started pouring and I didn't want papers in my wallet to dissolve. I found myself consistently going either 400-600w or 0w on the slightly-downhill road, maintaining 250-300w on the flats and 300+ on the slight rises. My average ended up a good 40w lower, about 200w. My heartrate stayed higher, 170 bpm, and that was totally consistent, like I meant to do it (lol).

It might be that you'll need to find an industrial park or similar (mall parking lot when it's closed?) and ride loops. Or time trial up a road that goes into NY (seems to be longer stretches of road up there).

One-legged drills - I found them to be slightly helpful, after two-three sessions where I do a maybe 2-3 x 1 min on each leg, I find that one legged drills don't do much for me. I can spin pretty fast on rollers with one leg and I think I was doing 600w with one leg on the trainer. It'll let you figure out how "pulling up" feels, that's for sure.

I find I have a LOT more speed with a slightly higher and very forward saddle position (combined with a low bar position), not pedal speed but bike speed. I think it has more to do with torso-ground angle, leg-torso angle, bar drop, and available breathing room. My pelvis tilts forward just a bit, letting me flatten my back better. I used to do this at an even more extreme but all sorts of things would go numb - my hands, crotch, my vision would double/triple (cricked neck), etc. My position is less extreme now. I'd say pedal force is my strength, not rpm, but I can spin fast if necessary. My cardio is suspect to say the least.

My max rpm on the spin bike was with 170mm cranks and the seat dropped all the way down (286 rpm). But with 175mm cranks and the seat similar to my normal height, my max rpm dropped into the low 240s. On my bike, with no weighted fixed gear wheel and the seat up to my "race height", it drops down to about 205 rpm.

cdr

Yes.

Would the effective gear ratio play into this at all?

You would think that it helps since taller gears would help smooth things out. However, from the replies above, and all things that I've felt, not to a considerable enough degree to compensate for the other factors that CDR, Danno and others have put into words so well.