power vs cadence?

islandboy

Now that I am back riding after my colon surgery, I have really focussed on spinning. My most comfortable cadence is between 100-105 with light pedal pressure. I can maintain this for up to 115 km - 4 1/2 hours (so far). I find that anything lower than 95 results in "power" riding which plays me out still. Hills are still a bit of a trick, though the short ones I can accomplish easily spinning at 115 - 120.

I was out riding with "the boys" when one of the stronger riders told me I was wasting wattage by spinning so fast. I find my recovery time is good, and I am not winded by the high cadence. As my surgery affected my digestion I have focussed on spinning a fast cadence to focus on lung ability over calorie consumption.

Am I on the right path? I appreciate any advice.

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Steve

Cycletouring through Victoria, BC, Canada?

Alex Simmons

Pedal the cadence you feel comfortable with. No harm in trying out difference cadences time to time but for the most part, cadence doesn't matter. If you are keeping up with your bunch, who cares how fast you spin your legs?

Power = cadence x force (well circumferencial pedal velocity x tangential pedal force) but it's basically the same thing.

So by pedalling faster you are applying less force each stroke. Others prefer riding at lower cadences and applying more force to genrate the same power.

Do what feels right for you.

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Alex Simmons

Your total body calorie "consumption" is only determined by your thermodymamic efficiency (~23% of total energy burned ends up pushing the bike, rest is mostly dissipated heat) and the energy (kilojoules or calories) produced during the ride (determined by avg bike power x time).

Your cadence is irrelevant, it is the ride power and duration that matter. Unless you have some reason to believe your body's thermodynamic efficiency varies greatly with cadence, which I doubt very much.

The only way to burn more calories is to either pedal at higher power level, ride for longer, or both.

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islandboy

Thanks Alex. My body is telling me I am doing the right thing regarding spinning. My recovery time is short and I find I can accelerate with ease when required.

Is there a simple way to calculate power?

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Steve

Cycletouring through Victoria, BC, Canada?

Alex Simmons

1. install a power meter (best way)
2. use power calculator at analyticcycling.com to estimate power at a given speed and gradient.

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mullerrj

"but for the most part, cadence doesn't matter"? I disagree wholeheartedly. In fact, this is actually a good question- power vs. cadence?..and I'll give you a good example of a 100 mile ride I JUST got done..where I think so. First of all, my 100 mile ride was hilly, over 6000 ft of climbing and we averaged 18.5 mph. Secondly, my legs were spent when I was done..you talk about lactate buildup..yikes. When I got done the ride..I downloaded my HR monitor because I wanted to see how long I rode in L4 (LT Zone). To my surprise, little or no time was spent in L4 at all..everything was below L4. That's telling me that I probably could have saved my legs more on the ascents by using a lower gear and spinning higher rpms...albeit maintaining the same pace. It would have driven up my HR a little bit, but so what...it would have saved my legs. In my opinion, you want to strike a balance between power and cadence. Cadence DOES matter...at least I think so.

Alex Simmons

No where did I say don't "spin" or dont "grind", I just said do what feels right for you. If your lower gear on climbs is better for you then go for it! But cadence is over cooked as an issue, power is what matters.

Cadence matters most when it is a ride/race specific issue, like when riding fixed gear on a track, then you have to take it into consideration. Eveyone else has gears to pick whatever cadence they prefer/desire.

I am not surprised you didn't do much L4 during a 100m ride. Not sure you'd really know anyway without a power meter, I found HR quite unreliable as a guide to actual effort and over a long ride like that HR to power would fluctuate anyway. You perhaps did some while climbing though as it is common to lay down more power when going up - sort of a natural reaction to the added resistance of the hill.

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mullerrj

And no where did I say you did (don't spin/grind). Where did that come from? Re-read my post..I'm taking issue with your statement about cadence.

Not surprised I didn't do much L4 during a 100 mile ride? Why is that? I had a 65 mile ride the week before and spent half of it in L4. Re: not really knowing without a power meter..I do know, because I train with a power meter at least 3x a week..just didn't have it on this particular (100 mi.)ride..so I usually know for a given HR and percent grade hill what power I'm producing. I say "usually" because as you know there are many external factors that affect HR: temperature, hydration, etc.

BTW, did you know that the world record 1 hr. TT has NEVER been broken outside the 100-106 rpm range? I think cadence DOES matter..that's all I'm saying.

Frigo's Luggage

I am not an expert because I only had one day of high school physics. However, I think that the physicists on the list will tell you that cadence is one of the componants of power. Simply increasing cadence with a given force and you increase power.

Putting aside the physics part of the equation, training with a high cadence is important from a neurological perspective. The concept is known as motor programming. You have to teach your legs to spin at high cadences for your legs to spin at high cadences. By doing high cadence drills, your preferred cadence will increase and you will increase power. If you do nothing but ride with a cadence of 80...well, you will simply be a triathlete.

The old timers used to say that the guy in the lightest gear was usually the classiest rider.

So, cadence is important.

Alex Simmons

All I was trying to say to the OP is ride the cadence he feel best with/prefers and not to sweat the cadence too much. Not intended to put words in anyone's mouth.

Typically I wouldn't call a 100mile ride an L4 session but if you can do lots of L4 on a long ride, good - I assume lower L4 rather than up near FTP for the distance quoted. Great, you have a PM so you know the HR impacts well, that's cool, you know what I mean. I find PE better than HR to guage power if for some reason I don't have a meter but that's just me.

Perhaps you were fatigued that day and just couldn't ride L4. What was your CTL/TSB like?

And for the hour record - I did say it matters most on a fixed gear/track. So I think we are in agreement there.

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dkrenik

I've read both your posts and you two are not quite connecting.

Alex is saying, if I may Alex, that "don't worry about cadence - it's self selected". You're saying does matter and I agree - to a point. It only only matters if you're looking at doing stuff outside of your normally selected range.

The data re: hour record, only shows that world-class elite riders pedaling at their 1 hour max power tend to favor a cadence of 100-106. Not sure how applicable that is to regular "schmos" like me. We're all wired just a bit differently and need to do what's right for us. Just because Lance pedaled at X cadence doesn't mean it's going to be right for me.

mullerrj

Alex..I guess the other point I was trying to make with one of my other posts was..today I went with a cadence that felt best for me..and when I got done with sore legs from too much lactate buildup I was starting to think..hmmm..maybe I should have spun a little higher instead of mashing a bigger gear up some of those 14% grade hills. Don't get me started on PE..hahaha..I hate that..that's if you're referring to "Perceived Exertion". Just don't like it..since it's too dang subjective. I'm an engineer so I like numbers- quantitative read outs. Granted, HR alone is not a very good tool..but it's all I had on the ride today. I use any tool I can- Power Meter, HR monitor, etc. Today I didn't have a full toolbox.

Nah, I wasn't fatigued that day..just rode with a Cat 2/3 racer..trying to stay on his wheel. Today was no better, my riding partner wasn't a Cat 2/3 racer but rode RAAM last year..so he was no slouch either.

I just thought this was a good thread to respond to since I just got done a ride today where I thought I could have upped the cadence a bit...and saved my poor legs. I probably won't be able to walk very well tomorrow..hahaha Thanks Rob

dkrenik

Force (torque) x Speed (cadence) = Power

I would say that i don't really care whether the increase in power came from an increase in cadence or torque. I just need more power.

Not really. You have to be able to hold the same torque for the increased cadence otherwise there's no increase in power (see above). Just focus on doing whatever it takes to increase your FTP (or whatever) and don't worry about whether or not your cadence is at x rpm.

mullerrj

Food for thought- isn't it? Maybe it is applicable to shmos like us.