Negative. Slow twitch muscles are good for long periods of slower, repeated contraction whereas fast musculature is better suited toward sprinting shorter distances. You can train either type of muscle fiber...distance runners develop slow twitch efficiency as sprinters develop faster twitch efficiency. The physiological differences in said muscle fibers can be seen in physical size and mitochondria population density.

Either way, just getting on your bike is loading your heart up; unless you're trying to sustain anaerobic cardio for long lengths of time then I wouldn't worry about loading up the heart, that's what it's there for.

like the next time you race Alberto Contador?

If you can make it up the climb however, kudos .... (oh wait, how can I take that back?) Ah, forget it. Congrats to you, my goatlike fellow poster.

Those of us with a history of heart issues might be a bit more concerned with load on the heart ... if I spin too long sometimes my heart rate will spike and then I can't really do much ... standing or sitting ... except maybe sit down, on the side of the road.

I have to stand every now and then, and yes, it still puts a big load on my heart, but the tiny bits of rest between strokes (versus spinning a faster cadence) can extend my climbing capacity just a little bit, so that sometimes i can actually make it up the slight inclines which pass for hills around here.

Not that I couldn't climb a serious hill ... it would just take a while, having to push my bike and all.

If using very easy gears makes me goatlike, I'll take it...

Very well, I understand.

The tests find no difference in efficiency standing vs sitting. So just do what feels good at the time. If you watch the pros climb, they do this.

Define "efficiency." I'm willing to bet none of us are talking about what those studies are.

Nice image. where i can find images like that online. thank you. that is can happens in real. Two riders both is fit but one rider use wrong bike size or have select wrong sizes chain rings and cassette cogs is can happens that the one rider is cant pedal anymore?

Like, ride in a lab with the mask on that measures your breathing gases to calculate your metabolic efficiency. I think it was the GCN guys.

Thank you ... for not pointing out that I am the Last Man on Earth who should be giving advice on climbing.

Right. Metabolic efficiency is all you, cuz nobody else has been talking about that.

If you read the original post you'll find that my reply fits in perfectly.

Oh, I read it, and I disagree. If you'd like to explain how metabolic efficiency relates to the topic, though, I'm sure you could open up a whole new line of discussion.

Nobody cares that you disagree, chaadster.

Stick in the mud! Or is it "stuck"?

Those tests measure what they measure very precisely, but do they measure anything relevant to what most cyclists experience?

Are they using super-fit test subjects who can ride the entire test at a given rpm in a given position at a given power output with some minimal deviation ... something most riders simply could not do?

(And is that really what is being measured? How the body metabolizes fuel in two positions? or is the test measuring energy output through the muscles in two different riding positions? Not sure that is "metabolic" efficiency, more like mechanical efficiency ... a body metabolizes food just fine sitting or standing, I'd guess.)

As I understand it, we are talking about a rider who is working really hard just to make one climb, and who is not interested in "metabolic efficiency" or 'mechanical efficiency." We are talking about a rider using different pedaling positions and rhythms in order to extend his endurance, to more fully use all the different muscle groups by resting some (relatively) while working others relatively harder, and switching back.

The absolute efficiency of either position is not important if the rider simply cannot continue to pedal in that position.

When I cannot spin anymore because I might have heart problems, or when a more fit rider cannot spin anymore because of lactic acid buildup in his quads, he might stand up and mash a little to get some different muscle groups involved. He might then try spinning a little while standing to build up a little speed, if he is physically able, and when that hurts too much he might sit and downshift and try spinning again, and on in that general sequence.

The efficiency of energy transfer in one position or the other would matter if he actually had the option of riding the entire climb in one position or the other (as the test subject s might,) but the actual on-the road-rider is switching out of necessity—whether the one position is more or less efficient than the other in the lab is not pertinent because at that moment he only has the option of riding in one position—whichever one he was Not just riding in.

Those lab tests are useful in some cases, but in this specific case, not so much I think.

OP asked and I think the best possible reply, the one most accurate and most useful, is to tell him to mix standing and sitting, mashing and spinning ... and since that is what the pros do, and also what just about every rider here also suggested ... well, he will have to make his own choices.

I know I simply cannot stand and climb all the way up some of the hills (gentle inclines) I face on most of my favorite routes ... and sometimes I have to stand up because I simply cannot sit and spin. The only efficiency I am considering then is how much more efficient it might be to get off and walk compared to trying to ride.

About the only comment I'd make here.....as it applies to efficiency.....(and I'm no master of it so do as I say, not as I do).......be careful what you decide to do when you do it. Try to memorize how long you can hold one or the other and realize that the safest bailout is sitting.

I often muster the fortitude to stand for a climb, start to choke halfway up and realize I want to be back in the saddle but I know I'm gonna screw myself when I lose momentum by sitting & downshifting....(as quickly as I can and I believe I'm quick on the brifters).....and I'll have to regain that momentum, no matter how little and on top of the physical loss in efficiency, it also pisses me off and gets in my head.

Therapy much? LOL

Whether sitting or standing is best depends in large degree on BMI. Lighter riders will do well standing, while heavier riders will wish that their butts were supporting more of their weight. As per comments above, of course training makes a difference also: one gets better at what one trains to do. With a high BMI of 24, I do better sitting on a long climb and standing on a short pop-over. On long climbs, I'm best at a cadence of ~80, seated with my hands on the tops, back straight, and elbows well bent. I try to gear so that my cadence won't fall below 70 if I can possibly help it. My legs go bye-bye below that.

Regardless of whatever lab testing of the not-me may prove, climbing at the same speed, my heart rate standing is higher than my heart rate seated. Heart rate is a pretty good indicator of which energy sources are being accessed.

Be all that as it may, seated and standing use slightly different muscles, so changing off between these two modes may be helpful on long climbs or long rides. Hence it's good to train both. In any case, it's my practice to stand for one minute out of 10 on really long hard climbs. Even though that may redline me temporarily, for me it's still worth doing.

Another thing to consider is varying your seated position. Pushed back you will engage muscle groups differently than by being forward, " on the rivet " as it were. On long climbs you can get some relief by varying your position. On long climbs, unless you are in a race, momentum means very little, so don't hesitate to shift to a lower gear and give yourself a momentary break before the climb; settle into a comfortable pace. A large part of climbing is psychological and tiring yourself out early on can make getting to the top more difficult.
One reply wondered where the term " on the rivet " came from, perhaps in jest, but I don't think so. Just look at a Brooks saddle

OP, just keep climbing and you will figure out what works best for you, as long as you aren't hurting yourself. It's generally agreed that a higher cadence is easier on the knees, but ther are mashers who do quite well.
Most of us remain seated for most of the climb, but there are those who stand a lot. I climbed a 9 mile canyon here with a guy who stood the entire way, and he was no light climber.
I also rode 10 miles across the valley with a pro who stood up the whole time while I was red-lined.

forgot to add, be sure you have a low enough gear if you are doing any sustained climbs. I climb about 300,000 feet per year and I'm old and fat so I use a 34x29 low gear.

Is that Chris Froome as a teenager?

GH

"when you stand for a short spurt, drop a gear or two for more resistance, but still aim for a medium cadence"

On long hills, combining sitting with some standing for a break and some air, works for me. As 12strings points out, you'll want a somewhat higher gear when you stand, especially as you get into better shape. In my motion to stand I'm up-shifting 1 or 2 or 3 depending on how I'm feeling. I may only take 20 or 30 strokes before sitting down-while at the same time downshifting back to my easiest gear. As has been said, keep your cadence up. There's a mild hill on a loop I do frequently and I try to make it up to the same point each time while standing; in other words setting a goal and increasing that as you get stronger.