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Is there any difference in aerobic effort in gear choice. E.g. In a low gear I am peddling faster to cover the same distance at the same speed that I cover with less revolutions in a high gear. In the higher gear, though the cadence is slower, it requires a different effort. It seems to me that the effort would equal out in energy required? Anyone have any research on this?
 

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I'm no expert, but I'm guessing if everything being equal, e.g. terrain, speed, wind, etc., is the same. it would take the same amount of energy spinning or mashing. It takes a certain amount of force to move an object from one place to another at a given rate of speed. Doesn't matter how you do it.
 

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Mr. Versatile said:
I'm no expert, but I'm guessing if everything being equal, e.g. terrain, speed, wind, etc., is the same. it would take the same amount of energy spinning or mashing. It takes a certain amount of force to move an object from one place to another at a given rate of speed. Doesn't matter how you do it.
True for machines, a bit less true for humans. What you say is perfectly true from the crankarm on. But as we pedal, we need to lift the weight of our legs with each pedal stroke - an energy cost that doesn't propel the bike. Higher cadences mean we need to spend more on that motion per unit distance covered.

For that and some other reasons, high cadences are slightly less efficient that lower ones. However, that small efficiency loss is usually worth it, because the muscles fatigue much more quickly under high loads. It's all about finding the happy middle spot for the conditions, fitness, and recent exercise history.
 

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danl1 said:
But as we pedal, we need to lift the weight of our legs with each pedal stroke - an energy cost that doesn't propel the bike.
If the two legs weigh the same, no effort is required to lift one leg, since the force of gravity on the other exactly balances. If there is an imbalance, the only force needed is to raise the difference in weight between the heavier and lighter leg. This is recovered in the other half revolution when the extra weight of the heavy leg provides some propulsive force.
 

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I assume that a power meter would answer this question. So some PM useres might respond. I know the heart rate increases with cadence. I thought that 20 mph=20 mph in terms of watts regardless as to gear or cadence. There is a difference in heart rate response and muscle fatigue. But this is just my uneducated guess.
 
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StewartK said:
I've read in several different places that higher cadence demands more from your aerobic system while lower cadence/greater effort demands more from your legs.
This is true. Since I have increased my cadence from 78/80 to 90 +, I go a lot faster with less demand on my legs. It took a while to get use to this cadence because it will increase your breathing, but once you get into the rhythm with your wind,your legs will thank you.
 

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asgelle said:
If the two legs weigh the same, no effort is required to lift one leg, since the force of gravity on the other exactly balances. If there is an imbalance, the only force needed is to raise the difference in weight between the heavier and lighter leg. This is recovered in the other half revolution when the extra weight of the heavy leg provides some propulsive force.
Nice in stick-picture diagrams, not so much in the real world. The difficulty arises because we don't apply force in perfect circles. No matter how good we think we are at pedaling, we are still applying muscular downforce well past bottom center. Fighting our own muscles in opposing legs requires energy, but does not produce work. Also, the human body is a nice soft squishy thing, not a hard mechanical device. If we utilize the muscles of the rising leg to pull up to any effective degree, there is the internal, unrecoverable waste of transition from tension to compression (strictly; flexion to extension phases) within the leg. If on the other hand we're letting the rising leg take a free ride, we are, well... Last.
 

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danl1 said:
No matter how good we think we are at pedaling, we are still applying muscular downforce well past bottom center. Fighting our own muscles in opposing legs requires energy, but does not produce work.
Nice feint, but I'm not taking the head fake. The subject wasn't working against the contractile force of the upward moving leg pushing down on the pedal, but raising the weight of the upward moving leg. The two are not the same.
danl1 said:
But as we pedal, we need to lift the weight of our legs with each pedal stroke - an energy cost that doesn't propel the bike.
 

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danl1 said:
Nice in stick-picture diagrams, not so much in the real world. The difficulty arises because we don't apply force in perfect circles. No matter how good we think we are at pedaling, we are still applying muscular downforce well past bottom center. Fighting our own muscles in opposing legs requires energy, but does not produce work. Also, the human body is a nice soft squishy thing, not a hard mechanical device. If we utilize the muscles of the rising leg to pull up to any effective degree, there is the internal, unrecoverable waste of transition from tension to compression (strictly; flexion to extension phases) within the leg. If on the other hand we're letting the rising leg take a free ride, we are, well... Last.
If you are still applying force at the bottom, your butt is going to come off the saddle. If you are bouncing, you know it. - TF
 

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StewartK said:
I've read in several different places that higher cadence demands more from your aerobic system while lower cadence/greater effort demands more from your legs.
Your legs are part of 'aerobic'. You may mean something like cardio-pulmonary??? - TF
 

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Discussion Starter · #13 ·
StewartK said:
I've read in several different places that higher cadence demands more from your aerobic system while lower cadence/greater effort demands more from your legs.
I guess this is what I was thinking. Sort of like the difference between "reps" and weight in weight training.

Since getting backing into cycling, I find I often kill my lungs but never tire my legs. I think maybe I need to up the cadence to improve my conditioning?
 

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CalypsoArt said:
Is there any difference in aerobic effort in gear choice. E.g. In a low gear I am peddling faster to cover the same distance at the same speed that I cover with less revolutions in a high gear. In the higher gear, though the cadence is slower, it requires a different effort. It seems to me that the effort would equal out in energy required? Anyone have any research on this?
Yes, because in a sufficiently high effort/gear you tend towards non-aerobic, so your implicit premise of a pure aerobic effort no longer holds. Which partially explains why sprinters stomp slow-twitchers in the sprints but the latter stomp sprinters in the long climbs.
 

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Since getting backing into cycling, I find I often kill my lungs but never tire my legs.
A lot of people make the mistake when running or cycling, of pacing their breathing with their cadence...i.e. a runner who takes a breath with every step. The faster they go the more they breathe. This can wear out the thoracic diaphragm (the muscle, not the birth control device) and the lungs far faster than the muscles of the legs.

I try to take long, controlled breaths when I am cycling, independent of my cadence. I can take in more oxygen for my muscles and increase my endurance.

Works for me.
 

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TurboTurtle said:
If you are still applying ENOUGH force at the bottom, your butt is going to come off the saddle. If you are bouncing, you know it. - TF
Fixed it for you. If we believe we pedal perfect circles, we are deluding ourselves. Best cyclists in the world can't.

But don't believe me. (page 131 if the link doesn't work as expected.)
 

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danl1 said:
Fixed it for you. If we believe we pedal perfect circles, we are deluding ourselves. Best cyclists in the world can't.

No one said they pedaled in perfect circles, but even Burke is showing very little 'muscular' force applied at the bottom. Lack of bounce would tend to confirm this - at least not enough force to lift the weight of your butt off the saddle. - TF
 

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TurboTurtle said:
danl1 said:
Fixed it for you. If we believe we pedal perfect circles, we are deluding ourselves. Best cyclists in the world can't.

No one said they pedaled in perfect circles, but even Burke is showing very little 'muscular' force applied at the bottom. Lack of bounce would tend to confirm this - at least not enough force to lift the weight of your butt off the saddle. - TF
True. But 'little' is still 'loss', the topic of the day. Lack of bounce only shows that it's not a completely absurd amount.
 
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