Faster cadence on hills means less fatigue, more slow twitch fiber use
The Spinning and several other IC programs encourage a cadence range of 60-80 rpm when climbing. While I do think there is merit to climbing at slower cadences on occasion, such as drills or hill segments aimed at strength improvement at around 55rpm (or to simulate a reeeeally steep hil), for the most part I suggest cadences of 60-80rpm. (e.g. my audio PROfile Got Strength had a song of 55 bpm/rpm, but the purpose was gaining strength, and it was only one song).
I have one student who rides at a fairly low cadence, at times causing her to pull on her handlebars more than she needs to. Not excessive mind you, but time after time, I’ve noticed she prefers cadences in the low 50’s when climbing. I know she mountain bikes in the summer and that she would be much more effective if she could raise her preferred climbing cadence to the mid 60’s or more.
Our bikes are pretty tightly packed so it’s very difficult to walk around, and she always leaves early to get to work by 7:30 am so I haven’t been able to talk to her directly. But what I did today finally (hopefully) got through to her to speed it up a bit on the climbs. Some of the cues I have given to my class to help them focus on the correct cadence (often directed at her) include the following:
- I’m pedaling at about 65rpm, make sure you’re somewhere close to my cadence, give or take a few rpms.
- Look at my feet! If you’re pedaling much slower than me, you have too much resistance on!
- Hear the beat? It’s about 62 rpm. If you want you can use that as your guide for your cadence, but don’t be any slower than the beat of this song.
This morning I was doing hill repeats at threshold, with each hill a suggested cadence between 60 and 70 rpm. I was using some of the above cues, but still she was pedaling around 50-ish rpm. We had just finished a 5+ minute climb to the song The Wall, a remix of the Pink Floyd song. The song gave me an idea that I needed to “educate” them on why a higher cadence is preferable on climbs. Here is what I said while they recovered in between intervals:
OK, everyone. I know the song just said “We don’t need no education” but if you’ll bear with me, I’m going to ignore that and give you a little education! You cyclists will really appreciate this knowledge. If I’m blinding you with science, then shut me out and don’t listen for the next few minutes as you recover on this flat road. I’ll try to keep this short!
Suppose you have a choice of pedaling at 50 rpm or 6o rpm on a given steep hill, and suppose you can do either one at the target heart rate goal (in this case LT). You might think you’re getting more benefit at 50rpm because the slower one will give you more of a sensation of work in the legs. But here’s why it’s important to try to increase your average cadence on hills, especially for those who do ride outside (but it’s also good for those who don’t).
You have two types of muscle fibers*, Slow Twitch and Fast Twitch. The Slow Twitch ones prefer aerobic metabolism and can use oxygen more effectively, and they don’t tire as easily. As you know, today’s hill repeats @ threshold ride has a goal of improving our aerobic abilities at a higher HR, right to your LT. We want to use as many oxidative muscle fibers as possible.
(I got off my bike for this mini “lecture” and wrote 50 rpm and 60 rpm on the white board at the front of the room, and underneath each one I wrote ST and FT).
Your FT muscle fibers are for force generation. You use a higher proportion of them when your resistance is high, such as a steep hill or a higher gear. (You also use them at high cadences in sprints, but that’s because a large amount of force is needed with the big gear that you need to sprint properly – but that’s a different story…) These FT fibers fatigue more quickly, but they are strong and fast. These muscle fibers prefer anaerobic metabolism, and as a result there’s going to be a greater amount of by-products produced – lactate and Hydrogen ions.
(My students know that when I talk about H+ ions, I’m referring to the burning sensation caused by acidosis/anaerobic metabolism, and that the H+ ions can slow them down and hinder muscle contraction when they accumulate above LT).
Comparing these two cadences, 50 and 60 rpm, you will use a greater percentage of FT muscle fibers at 50rpm than you do at 60rpm, and more ST fibers at 60 rpm than you do at 50rpm. The same comparison can be made between two cadences of 60 and 70 rpm, and 70 and 80 rpm. Today our goal is more aerobic in nature. On this particular hill, you want it fairly steep, with somewhat slow cadence 60-65rpm, but not so slow that you really are using too much of your FT fibers, like you will if you’ve got so much resistance on that you are forced to pedal at 50 rpm.
Then I wrote that on the white board. Underneath the 50 rpm, I put an up-arrow next to the FT, indicating a higher percentage there, and underneath the 60 rpm I put an up-arrow next to the ST indicating a higher percentage there. By writing it on the board like this, they got a visual of what I was describing (helping those who are more visual in their learning styles).
I went on…
This, by the way, is one of the reasons why Lance Armstrong worked so hard to increase his cadence on hills over the years. He relies less on the easily fatigued FT fibers and more on the more resistant higher endurance ST fibers. He saves his FT fibers for when he really needs them!
So, for those of you who prefer to pedal really slow, think again! If you have it available to you, if you have another gear, you will be better off with a little less steepness and a little higher cadence!
That ends our physiology lesson for the day. As Pink floyd said, we don’t need no more education – Back to your regularly scheduled broadcast…
And we got on our next hill.
Then while climbing, I thought I should clarify one thing about what I had just said. While we were recovering after that climb, I added…
By the way, there are diminishing returns on that example I just gave you. Yes, a slightly lower gear and higher cadence will be more efficient and fatigue you less over time, even at the same heart rate – and if the change is subtle, you can probably even climb at a faster speed. But you can’t take it to the extreme, and for those of you who do ride outside, you must balance it with how fast you intend to get up your hill. If you take your cadence from 60 rpm to 85 rpm because you dropped into your easy granny-gear, your power output won’t be very high and you’ll slow way down. You’ll drop from, say 7mph on this hill down to 5mph and it will take you forever to get up it!
And no one here wants to be the last one up Vail Pass, I’m sure!
If anyone has any questions about that, ask me after class. It’s time to get on our next hill!
Hopefully you can use a similar explanation to your students to help those who like to ride big gears when climbing. If you, the reader, has any questions about this, leave me a comment below.
* note: I kept it simple as possible, and didn’t delve into the fact that the fast twitch muscle fibers actually are broken into two subcategories – Type IIa fibers and Type IIb fibers. Type IIa fibers are more oxidative and can even increase the number of mitochondria with training, hence becoming more aerobic than their counterpart. These are known as FOG, or Fast Oxydative Glycolytic. The Type IIb fibers are far more glycolytic and are known as Fast Glycolytic and fatigue the quickest. If you want to train your legs to climb longer before fatiguing, use more ST than FT muscle fibers!
8 Responses to “Faster cadence on hills means less fatigue, more slow twitch fiber use”
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I will try not to say absurdity …
Slower pace big gear = a lot of stress for the muscular system, mostly like lifting an heavy load, you use a lot or big muscle fiber FT
Faster pace = less stress on the muscular system, so you use less muscles fiber at a time ST
But what about the cardio system
Slower pace = less blood movements, one problem the pressure in the legs just don’t let the blood move (compression) = more tension
Faster pace = more stress on the cardio system.
Yes faster pace are more effective but until a certain pace, Lance can maintaint his “incroyable” pace because he trained a lot in HIT with faster pace, his body his cardio is now acclimated to faster pace.
One difference between the old and the new Lance is, that he just raised his LT, so now he can maintain higher cadence.
I personnelly don’t climb inside like outside that is pereaps a mistaque but I don’t know. Indoor I am a pusher Vs outdoor I am a spinner.
I think that the load I am pushing inside help me to have a better stroke.
When I do tempo and faster pace indoor I feel it help me more on the flat road ?
But of cause what ever is your pace it have to be smoud so 50RPM if it is smoud why not, but if you have a specific rider who can just ride at 50 yes you have to help him/her to be able to turn a little faster.
This woman rides mountain bikes. The fact is, she pedals too slowly because she chooses too large a gear. She would without a doubt be far more efficient and fatigue less quickly if she raised her average cadence. She’d also probably be faster over time. She’s a masher. It’s better to be a “spinner” when mountain biking (road biking too, really).
Since she rides with me twice a week to train for her mountain biking in the summer, she has an incredible opportunity to improve/increase her preferred cadence while climbing. Remember the principle of specificity of training! It also applies to speed of contraction. In cycling that means training in a similar rpm range to what you will be (or should be) using outside.
Completely separate from raising one’s LT, your gear and cadence choice has a large impact on your level of muscular fatigue. If you want to climb a long time, better to select one gear lower and a few rpm faster.
In addition to that, like you said, raising your LT will also have an effect on extending time to fatigue, but for different reasons. This is not so much muscular fatigue, but metabolic fatigue. A higher LT means a greater number of heart beats before you rely on your anaerobic metabolism. A lower LT means “burning matches” earlier and more often every time you exceed it (I often use Hunter Alen’s match analogy – which I’ll explain in more detail on another post). Basically we all have a different size match book with different # of matches in it – based on our training. A higher LT means less chance of burning matches and fatiguing quicker because you ran out.
Does that make sense?
A personal observation on cadence (related to road riding):
Over the years I have been working hard at improving my cadence as I ride (or, increasing my cadence). I had always been on the lower end, preferring to ride in the low 80’s on the flats and mid-to-high 50’s for climbs.
Keeping my power (or speed if I was riding without a power meter) the same, I have experimented with ‘preferred’ cadence and higher cadence (90’s on flat; high 60’s climbing). Without fail, I have noticed the following (again, maintaining the power or speed and varying the cadence on the same stretch of road):
1. Higher cadence = higher heart rate
2. Higher cadence = less fatigue in the muscles
I am working at the higher cadence and I am seeing my LT increasing over the years. Result is that I am riding further, with less fatigue, at the same speed I used to.
Taking everything indoors, I have found that at a given effort, heart-rate, my cadence indoors is almost always 10 rpm higher than outdoors.
Great observation – and in line with the findings of exercise physiologists.
Indoors it’s just easier to pedal faster with the help of the flywheel – even though we think we are “managing” it. It’s easy to convince ourselves that we are!
My cadence outdoors on the big climbs around (8-10%) here used to be low 50’s on the tougher climbs in my LOWEST gear. Obviously tough on the knees. So my next bike purchase I got compact gearing which gave me slightly lower options for gears. Now I can ride in the high 50’s on the toughest climbs. Still low, but not as low, not as fatiguing, and not as tough on the knees – allowing me to get to the top faster than before by using a lower gear and higher cadence (a few rpms). May be counter intuitive, but it works!
Admittedly, my pride wouldn’t let me get a triple chain ring (giving me even lower gears); It didn’t help when a cycling girlfriend said, “Jennifer, we’ll get triples when we’re 80!”
All that to reinforce what I was trying to emphasize in my post. A lower cadence indoors occasionally will help you with some strength, but too low and you’ll fatigue faster at a muscular level at a given heart rate or power output. The discussion of the FT vs ST muscles is just an attempt to point out the physiological reasons behind this.
By the way, I meant to mention that photo above. It’s clients of mine on the Col de Glandon in the French Alpes. It’s an Hors Category climb (meaning frickin hard), 24 km, average grade of 5% (but that “average” is deceiving because there’s a flattish section in the middle, but there are some extended 10% grades and some sections up to 15%). Often used in the Tour de France (the base is 10 km from the base of Alpe d’Huez). 1,152m elevation gain (almost 4,000′)
You can’t compare two different people, but let’s say a woman rides up Glandon a couple of times over a few weeks and noticed her average cadence was 60 rpm (except for the flat part), but that she often found she had another gear or two (except on those 12-15% sections). Let’s say it took her about 2 hours to complete, and that she kept her intensity just below threshold for most of it (in order to guarantee that she’ll make it to the top), except those 12-15% sections; believe me, on those, you just put your head down and dig in!
Now suppose she goes back, completely rested and tries to do it with a faster cadence, average of 65rpm, using that extra gear if available and not because she’s racing up. [Keep in mind, she won't go lower in gears on the toughest parts because she was already in her lowest gear, and didn't want to go higher in intensity either because she was already at or over threshold, so she didn't raise her cadence there].
Findings: MOST likely she will find that she won’t be any slower in a lower gear, she may even be 5-10 minutes faster, but her overall fatigue in her legs is a little less.
Now that’s a GOOD thing, isn’t it?!
I’m a little late to the discussion but this is timely for me, personally, as yesterday I was talking to a friend about FT vs ST and why he will never hear me say “fast twitch” when I’m teaching a spin class.
I prefer a high cadence indoors and out (and definitely I average higher indoors) and in my small riding group can often get to the top of a hill first regardless of where I started. My friend was asking me questions about my gearing choices and truthfully, I had no idea. “I just keep it somewhere where I can pedal fast without slowing down too much.” Not the technical answer he was looking for but it did lead in to the fast twitch/slow twitch conversation.
This quickly became very confusing in part because of the cues used by several IC instructors. During cadence drills they’ll cue “fast twitch!” as we’re all cranking away. It’s used the same as “keep it coming” or “hammer” etc.
Now I know very little about the role FOG FT fibers in this setting (high cadence, flat road) and so perhaps it’s a reference to THOSE FT fibers, not the OTHER FT…but even if that’s true, I doubt that’s what the ICI’s have in mind when they say “fast twitch.” It’s my understanding (and your article seems to back me up on this one) that it’s actually your ST fibers that are recruited when maintaining a fast, sustained pace – on any given terrain. But I could be way off base.
Can you shed some light on how these 2 (or rather, 3) types of muscle fibers are tapped when the road flattens out?
thanks for the excellent question, Shelly. You are right. The faster cadence requires slightly less muscular force so it relies on a larger percentage of slow twitch muscle fibers. It’s a bit counterintuitive that you use more ST than FT fibers when pedaling faster. But spinning the legs at 75 or 80 rpm on a climb (versus 60 or 70rpm), or even 90 or 95 rpm on the flat (versus 80 or 85 rpm) for long periods isn’t so “fast” that the fast twitch muscle fibers are recruited as much.
FT (glycolytic) are used for force production. They can contract more powerfully against a resistance, so those are the ones used for the steeper, harder climbs (or higher gear choice) at slower cadences. They fatigue more quickly because they rely on glycogen as a fuel and produce more lactate and H+. They are ALSO the ones used for very fast cadence, and very powerful sprinting – but the key in that equation is that there is high resistance in a power move like a sprint. (Which is lost on so many IC students and their instructors who are “sprinting” at 140 rpm with no resistance).
The FOG, the “Fast Oxidative Glycolytic” fibers (Type IIa) have some of the characteristics of the slow twitch muscle fibers, with more mitochondria where aerobic metabolism takes place – hence the term “oxidative” because mitochondria is where the oxygen is utilized. Therefore, they can be utilized at those middle range yet somewhat faster cadences on climbs and flats where you select one or two gears less in order to spin the legs a bit faster. They can even be “taught” to be more aerobic – this is why it’s easier to teach an anaerobic athlete to be more aerobic than it is to teach a predominantly aerobic athlete to be more anaerobic.
By the way, I use the word “teach” in a metaphorical way – what happens is with enough use, you create physiological adaptations that can cause changes in your own metabolism and makeup. Your FOG fibers can adapt to be more aerobic and fatigue resistant if you train them to be. Otherwise they will assist the Type IIb glycolytic fibers, be more powerful, and fatigue more quickly.
It sounds like you’ve been doing this intuitively when you are climbing. By choosing one gear or so less, your legs don’t fatigue as quickly. A higher gear at a slower cadence might allow someone to go at a higher speed, but depending on the length of the climb, there may be diminishing returns as the muscle fibers will tend to fatigue. On the other hand, you have to select your gear and cadence with your desired speed (and power output) in mind as well. Drop down too much of a gear/resistance with too much of a cadence increase and you’ll be passed by grandpa wearing his beret on an old one-speed bike with fenders!
On a flat road it’s the same thing – you can choose a gear that will allow you to pedal at 95 rpm or you can choose a gear that will allow you to pedal at 85 rpm – suppose both options produce the same intensity (HR). A “masher” will choose the latter option and a “spinner” will choose the former. On short distances the masher might come out ahead, but on long rides (especially 50-100 miles) the spinner will arrive at the finish line with less fatigue and most likely with less glycogen use (which in some cases can fend off a bonk, and in most cases will also lead to less fatigue and quicker recovery in the days to follow).
Indoors, we are just simulating these choices when coaching our students to ride at certain cadences.
Sheesh, I didn’t know there were instructors out there who were using cues like “Fast Twitch” when cueing faster cadence drills. That’s the problem when they learn just enough to be dangerous – they misconstrue the information and teach the wrong thing.
Actually, there’s very little reason to teach our own students about FT and ST fibers – their eyes might glaze over! That is, unless you are dealing with athletes who have a need or interest in knowing. I have mentioned it to my own students on occasion, but rarely. On the other hand, I do think instructors should know the difference. It will help in cadence selection and in understanding things like the topic of this post – why, when and how you fatigue faster when using FT than when using ST fibers.
Thank you for clarifying, Jennifer. I somehow cannot imagine myself explaining muscle fibers to my classes, even if they were genuinely interested – the confusion and clarification relating to well-intentioned but inaccurate spin room cues would take up the whole hour!
And yes, I definitely handle my bike in a more “touchy-feely” way than some of my fellow riders. I had a crash course (not literally, thankfully) in gear ratios as they pertain to switching chain rings but that’s about the extent of my technical riding knowledge. But don’t get the wrong idea – I’m not technically inept with regards to the bike itself, the mechanical – I’m just not paying attention to what gear I’m in when I’m actually on the bike.
And for what it’s worth I happen to have a triple (I say “happen” because I bought the bike before I really appreciated what that meant – lol!) and I pretty much would die before using that granny gear. Someone pointed out my triple during our little ST/FT conversation. It did make me smile when one of the guys I was talking to pointed out that I didn’t use that third ring on that day’s ride. (He was the only one close enough to even be able to notice.) lol!