A Scientific Explanation of Why Cycling Hurts

07.7.2009 | 7:11 am

A Note from Fatty: If you missed yesterday’s post about how you can win a cycling vacation in Italy or a pair of top-of-the-line Sidi shoes, you should go back and read it, then enter before it’s too late. Both contests end tomorrow (Wednesday). And you really, really, really want to win these. Really.

As a very popular, handsome, respected, and award-winning blogger, I am frequently asked questions regarding bicycles. Here are some I’ve received recently:

  • What kind of bike should I buy?
  • What are good foods to eat before, during, and after a ride?
  • Is it important that I stretch before riding?
  • How should I select the right saddle for my anatomy?

At first glance, these questions do not seem to have anything in common. However, if you will dig a little deeper, you will realize that these questions do in fact share a characteristic. To wit: they are all stupid and uninteresting.

Let us dismiss them from our thoughts.

Recently, however, I encountered a question that caught my attention, primarily because I am the one who conceived it:

Why does cycling hurt?

The answer is not obvious. Consider other activities, for example. Driving an automobile does not hurt. Watching television does not hurt. Eating nachos does not hurt.

But cycling — in particular, certain aspects of cycling — does hurt.


I am pleased, after considerable research which I suspect will garner me still more awards and accolades, to provide the answer.

Introducing…The Pain Pellet

As most of you know, there are four commonly-known elements, from which all substances on Earth are made. These elements are Earth, Wind, Fire, and Cheddar. The more cheddar the better, but that is the subject for another paper.

What most of you do not know is that there is a fifth element, and it is not the one starring Bruce Willis.

No indeed.

The fifth element is Pain.

Unlike other elements, which can be combined to form other substances (nachos, for example, are a combination of Earth, Fire, and Cheddar), Pain keeps to itself, clumping into small balloon-like spheres called Pain Pellets.

While difficult to see, Pain Pellets are nevertheless easy to detect, for when touched by a human, they (i.e., the Pain Pellets, not the human) burst, splattering you with a certain amount of pain. The larger the pellet, the larger the pain blast radius.

And if one encounters several Pain Pellets while traveling in a certain direction, one will experience sustained pain.

Pain Pellets: Properties and Proclivities

The reason, then, cycling hurts is because cyclists — due to some cosmic accident — tend to frequent places where Pain Pellets generally congregate. Specifically:

  • Pain Pellets adhere to slopes. As everyone knows, an upward slope is in tension with the magnetic forces that some call “gravity” (I will discuss the folly of the theory of gravity another time, but for our purposes today, we can pretend that such a force does exist). A byproduct of this tension is friction, which in turn creates static electricity. Pain Pellets, being very much like balloons in both size and texture, are drawn to this static electricity on upward slopes, and cling to it. The steeper the slope, the greater the density and size of Pain Pellets collected.
  • Pain Pellets settle at the bottoms of treacherous places. Pain Pellets are subject, to a degree, to the normal forces of “gravity,” and will settle where you might expect them to: just below slippery roots, at the base of a three-foot ledge, and just beyond a surprise hairpin are three good examples. Mountain cyclists are particularly adept at discovering these Pain Pellets.
  • Pain Pellets are attracted to heavier people. A surprising fact is that if two people — let’s call them “Brad” and “Fatty” for no particular reason — ride up a given hill, the heavier one (“Fatty”) will encounter more Pain Pellets than the lighter one (“Brad”). Indeed, the Pain Pellets will actually move out of Brad’s way and wind their way toward Fatty. It is almost as if the Pain Pellets are sentient and find heavy people especially attractive. Some of my less-credible colleagues assert that the Pain Pellets find me because I have a greater gravitational mass, but this (of course) relies on the convoluted — and thoroughly debunked — theory of gravitational pull to work. For now, let us say that Pain Pellets like heaviness, and leave it at that.
  • Pain Pellets grow back quickly. Cyclists often attribute the “drafting” effect of riding to the thoroughly debunked notion that the cyclist in front of them creates a slipstream. In reality, the rider in front is hitting a disproportionate number of Pain Pellets, allowing the rider behind to ride the route relatively unscathed. Unfortunately, Pain Pellets reform in their original location in a mere matter of moments.

How to Avoid Pain

Of course, some cyclists find the near-incessant encounters with Pain Pellets sub-optimal, even to the point that the Pain Pellets may impede the cyclist’s progress. “How,” the cyclist may reasonably wonder, “might I avoid the Pain Pellets?”

There are multiple strategies.

  1. Slow down. When riding up a hill, one notices a surprising amount of pain. Further, the faster one rides up that hill, the more it seems to hurt. It is therefore worth noting, then, that one generally will encounter the same number of Pain Pellets, regardless of whether one is going up the hill very fast or very slow. However, since when going slow one encounters the Pain Pellets at a slower rate, the perceived pain may be decreased.
  2. Weave. When climbing a hill, one may reduce the frequency of Pain Pellet encounters by “paperboying” up the hill. Some theorize that Pain Pellets grow in long uphill strands and that by weaving one’s way up the hill, one may avoid at least some of these strands of Pain Pellets. In reality, though, one is actually encountering perhaps more Pain Pellets over the course of the climb, but since one is hitting them at a slower rate the perceived pain is again reduced.
  3. Don’t fall. One universal truth about Pain Pellets is that they remain on the ground. When one remains upright on one’s bicycle, one is merely splattered by the exploding Pain Pellets as one’s bicycle wheels burst aforementioned Pellets. However, when one crashes off one’s bicycle, one is almost certain to land directly on several Pain Pellets, soaking the cyclist in pain. It should be further noted that Pain Pellets do very little to cushion the cyclist’s fall.

In summary, Pain Pellets and the cyclist seem to have a strange mutual attraction. Cyclists are drawn to inclines and treacherous locations, which are the natural habitat of Pain Pellets.

And in short, the question “Why does cycling hurt” has a sensible answer based on pure physics. Cycling hurts because cyclists are drawn to pain.


  1. Comment by buckythedonkey | 07.7.2009 | 7:23 am

    Pain pellets like heavies? I suppose I’m going to hurt then. ;-)

    Amazing stage yesterday…


  2. Comment by Kalgrm | 07.7.2009 | 7:24 am

    Makes perfect sense to me.

    I guess they are afraid of fibre: I know if I don’t have enough fibre in my diet, I get pain pellets.


  3. Comment by Atomic | 07.7.2009 | 7:26 am

    Ha! I knew it couldn’t be because I’m out of shape! I’m just bigger and the pain is attracted to me! You’re a genius!

  4. Comment by DavidV | 07.7.2009 | 7:37 am

    well done

  5. Comment by dslunsford1 | 07.7.2009 | 8:05 am

    Excellent explanation. I always felt them junx hitting me but never knew what they were called. Any word on if they’re working on inventing some sort of umbrella or poncho to keep the rider from getting hit? I’d buy a couple of those. I hate the bubbles bursting under my wheels because they make my chain rust.

  6. Comment by KanyonKris | 07.7.2009 | 8:10 am

    Dr. Nelson,

    Congratulations on the publication of your Pain Pellet theory which I am sure will win you a Nobel prize. Long have you labored to understand this phenomenon (often using yourself as a test subject), surely this day is a vindication of your years of effort. The world will surely be better for your discovery.

    Dr. Kanyon
    Subcommittee Chairman
    International Institute of Paranormal Science

  7. Comment by Flatoutjim | 07.7.2009 | 8:17 am

    OK clever post, but,

    What kind of bike should I buy?
    What are good foods to eat before, during, and after a ride?
    Is it important that I stretch before riding?
    How should I select the right saddle for my anatomy?

  8. Comment by stefano | 07.7.2009 | 8:21 am

    Thank you so much for the explanation. Here I was thinking the reason it hurt so much when I crashed was because the ground was so hard. Now I know that particular theory was stupid and uninteresting. It’s gone from my mind completely. Avoid the pain pellets, avoid the pain pellets; stay upright and ride the flats, avoid the pain pellets. I’m buying a leisure bike!


  9. Comment by David | 07.7.2009 | 8:25 am

    Au contraire! Eating nachos DOES hurt. Or maybe you’re just not doing it correctly.

  10. Comment by axel in texas | 07.7.2009 | 8:26 am

    but why oh why does the butt hurt while riding?
    is it because the rear wheel flings those pain pellets up and that way and I should have fenders?

  11. Comment by Lowrydr | 07.7.2009 | 8:27 am

    I think there were Pain Pellets in my last order of Nachos. At least my wife said I was a real pain after eating them all.


  12. Comment by FatMass | 07.7.2009 | 8:35 am

    Don’t forget that the human body attracts exponentially more Pain Pellets when it is expelling libations that include alcohol.

  13. Comment by Bander | 07.7.2009 | 8:40 am

    I believe pain pellets should be considered not an element but as a Humour…it just makes sense that way. You know: blood, phlegm, yellow bile, black bile, pain.

  14. Comment by Evil Cyclist | 07.7.2009 | 8:42 am

    Pain pellets? How simplistic, primitive and naive.

    It’s so typical to create superstitious explanations for things that aren’t understood. Its time you know the truth.

    I created the Sub-Etha Pain-O-Matic ™ to redirect all pain away from my bike riding out to everybody else’s riding. Thus you all suffer horribly, while I ride of a fantastic cloud of comfort, the Charmin of Cycling.

    I fall down..you get the bruises. I ride a grueling century, my bum is rested and refreshed, you have festering sores. I ride through a briar patch..you bleed.

    Get the picture ? You hurt so the Evil Cyclist can ride in comfort.

    -Evil C.

  15. Comment by GenghisKhan | 07.7.2009 | 8:46 am

    Interesting. Are pain pellets in any way related to rabbit pellets, ‘cuz the theory kinda, well, you know, smells… ;o)

  16. Comment by Clydesteve | 07.7.2009 | 10:07 am

    It is almost as if the Pain Pellets are sentient and find heavy people especially attractive.

    MY head is spinning…. Is, then, my wife a pain pallet???

  17. Comment by Rantwick | 07.7.2009 | 10:16 am

    Wow! I loved that post. I am drawn to pain pellets, and my heaviness brings them to me as well. It finally all makes sense. Someone mentioned Nobel. I agree, and I will look into nominating the Unified Theory of Pain Pellets.

    You know, if you only spelled your name Elbon (come on, it’s only two letters), it would be jumble of Nobel! How freaky is that? I need to lie down…

  18. Comment by LuckyLab | 07.7.2009 | 10:42 am


    On a side note, Twin Six needs a huge thank you from San Jose participants.

    I entered as a virtual participant yesterday and plopped down a little seed money until I could chat with my wife about how much we could afford to donate. I go to log in this morning to find an $80.66 donation to bring me over $100.

    Thinking, what the heck, I look at the team page and realize T6 pushed EVERYONE to $100 for the Team Messenger award. Unbelievable!

    There is still time to get in on the action as the deadline in Thursday at 9 a.m. central time. (And, yes, I am a little competitive.)

  19. Comment by Philly Jen | 07.7.2009 | 11:01 am

    OMG, Twin Six is phenomenal!!!

    Brent and Ryan, you rock more than ever.

  20. Comment by MikeonHisBike | 07.7.2009 | 11:09 am

    I also think Pain Pellets have surrounded my trainer. I tried to clean them all off last winter but they kept coming back on a daily basis.

  21. Comment by Noodle | 07.7.2009 | 11:10 am

    Serious awesomesauce, Fatty. I may have done that LOL thing.

  22. Comment by Saso | 07.7.2009 | 11:23 am

    Dr. Nelson,

    how come that it does not hurt when one is biking downhill on a sharp slope at speed, thus encountering a lot of Pain Pellets on the way?



    You need to read my text more closely: “As everyone knows, an upward [emphasis added] slope is in tension with the magnetic forces that some call “gravity”

    I.e., pain pellets only accumulate on the uphill part of a slope. The downhill part of a slope does not have any, until you fall, at which point several Pain Pellets will rush to you.

    I’m glad I could help.

  23. Comment by bikemike | 07.7.2009 | 11:34 am

    “to the pain”

    “I don’t think I’m quite familiar with that phrase.” – FC

  24. Comment by e | 07.7.2009 | 11:36 am

    Wow. That’s a whole lot of folks in San Jose who now have “raised” $100.66. Thanks, T6! You guys are the best!
    Do you think wearing T6 gear does anything to repel Pain Pellets? I think it might.

  25. Comment by Fifth Column | 07.7.2009 | 11:57 am

    So, nachos are made of Earth, Fire, and Cheddar, but their by-product seems to be Wind. Interesting…

    And thus the universe continues to expand. – FC

  26. Comment by Hamish A | 07.7.2009 | 12:31 pm

    I’m heavy and I no longer feel pain. Is it possible that there’s a natural immunity that builds up? I hope so.

    Perhaps ice cream is the antidote to the pain pellets.

    That would explain a lot.

    Slightly off topic but in addition to the wonderful prizes you are offering the San Jose Team Members I am still looking to give away the Flip Ultra HD camcorder that was very kindly donated to me.

    Just make your donation to my Livestrong challenge page (click my name, it’ll take you straight there by magic) and keep your fingers crossed for an email on Saturday! The more you donate, the more bonus entries you get so don’t hold back! ;)

    My ‘training’ blog can be found here if you want to see what I’m doing to earn your donations: http://100omon2009.wordpress.com

    Good luck to everyone taking part in the San Jose Challenge!

    WIN SUSAN!!!

  27. Comment by SurlyCommuter | 07.7.2009 | 12:49 pm


    Aren’t brats also made of Earth, Fire & Cheddar?


    Yes, but in different proportions. – FC

  28. Comment by mikeb | 07.7.2009 | 1:47 pm

    Pain Pellets…that explains everything. About 10 days ago while traveling at 20+ mph I hit a dog straight on. I believe the beast was carrying a load of said pellets. Stiches in the face, 3 broken ribs, road rash from the nose to knees. The pellets are still releasing on me, especially when I move.

    But I have ordered a new bike and will be ready for Austin in October!!!

  29. Comment by cyclostu | 07.7.2009 | 2:04 pm

    Here I thought that Earth, Wind, and Fire was a supergroup from the 70’s. Turns out they are all scientific and stuff. Who knew.

  30. Comment by Bruce | 07.7.2009 | 2:25 pm

    Sounds very much like some of the theories of the late lamented Douglas Adams. Impressively researched!

    I owe 50% of my sense of humor to Douglas Adams (and because I know someone will ask: 30% to Monty Python, 20% to Steve Martin). I cannot even count how many times I have read the first 3 books of the Hitchhiker trilogy. – FC

  31. Comment by Bandit | 07.7.2009 | 2:40 pm

    I submit that pain pellets do not splatter. Rather, I believe they radiate like electricity. This would explain why my bum is more sore than my knees. The pain conducts through the rubber, metal and vinyl of my bike directly into my bum. It also explains why I do not feel pain when someone rides by me unless they ride so close that they come into contact with me.

  32. Comment by RRockinJ | 07.7.2009 | 3:08 pm

    I surmise that Pain Pellet residue is particularly hard to wash off after you’ve fallen very hard on to said pellets. That would explain why the huge gash on my arm still hurts from sunday’s mountain ride.

  33. Comment by Big Mike In Oz | 07.7.2009 | 4:12 pm

    As a trackie I’d like to add to this whole pain pellet theory. It is a well known (and well covered already today) fact that pain pellets adhere to slopes, the steeper the slope, the higher the concentration of pellets. Now think carefully about the steepest slope you’ve ever seen cyclists continually attack and conquer. Think again. Think clean. Think smooth. Think indoors maybe. That’s right, the velodrome with its 30, 35, even 40 degree banking is a haven for pain pellets. And more than that is the fact that the velodrome is an enclosure means that the pain pellets just keep accumulating. Until some poor soul touches a wheel. Then they land right in the middle of the greatest concentration of pain pellets known to man.

    And… “(nachos are a combination of Earth, Fire, and Cheddar)” … and Wind, but that’s an after-effect.

  34. Comment by Yukirin Boy | 07.7.2009 | 4:27 pm

    Awesome T6!
    may the pain pellets find you unattractive.

  35. Comment by Kathleen@ForgingAhead | 07.7.2009 | 5:21 pm

    These insights are sure to get me through my first century this weekend…thanks Fatty!

  36. Comment by Fat Cathy | 07.7.2009 | 6:07 pm

    The Twin Six guys are incredible. Thank you!

    And I’ll keep this pain pellet theory in mind on July 26 – my first race in almost 3 years. I’ll be chanting in my mind: “it is only a pain pellet, it is only a pain pellet. It won’t kill you.”

  37. Comment by Mike | 07.7.2009 | 6:24 pm

    My only question:

    If you have disconfirmed (spell check is wrong. Disconfirmed just hasn’t been accepted by the dictionary yet.) gravity, then wouldn’t “heaviness” need a new explanation? You are not heavy, but of a larger mass.

  38. Comment by PennyPue | 07.7.2009 | 6:58 pm

    What color should I get for my bike? Does it come in lime green? What about sand stone beige?

  39. Comment by bubbaseadog | 07.7.2009 | 7:08 pm

    fatty did you fall off your bike again….almost sounds like you did …really enjoyed your blog about your day in court but where else can you throw rocks you cant throw em in the city you might hit a car or a bike its not like they provide a rock throwing range. hey maybe there would be a mkt for that you think…winsusan gogo go lance.

  40. Comment by WheelDancer | 07.7.2009 | 7:25 pm

    Ha, too funny! I’ve noticed that the more I ride the less effect the pain pellets have on me so I suspect that their is some sort of immunity that can be built up. I can confirm, unfortunately, that hitting the ground negates any immunity that has been built up.

  41. Comment by Born 4Lycra | 07.7.2009 | 9:20 pm

    T6 once again confirm their LEGEND status. Onya Boys.

    Things are so clear for me now – Fatty you are an educator. I look forward to the upcomming lecture debunking the Theory of Gravity, I understand pain not just mine but everyone else’s and I truly believe you could explain the meaning of life being 42. Todays write up was really good fun. WIN SUSAN

  42. Comment by KanyonKris | 07.7.2009 | 10:59 pm

    And Earth, Wind & Fire make music (well, some people think so).

    Truly you have a dizzying intellect.

  43. Comment by Mike Roadie | 07.8.2009 | 5:11 am

    TWIN SIX is the awesomest!!!

    I remember the video game Paperboy—that takes me back……just like Nachos…….yummy…….

  44. Comment by fitnessbikes | 07.8.2009 | 5:20 am

    Really nice article….thanks! for this.

  45. Comment by Jenni Laurita | 07.8.2009 | 6:18 am

    Let’s all innundate Chalkbot with Win Susan messages! You can follow them on Twitter. I just sent a request.

  46. Comment by MattC | 07.8.2009 | 1:01 pm

    I am just guessing here, but is it possible that the pain-pellets somehow slip up/over/around someone on a ‘bent’ when they are descending or on the flats, yet somehow congregate in even larger quantities for the climbs? Maybe at speed they just don’t suck around fast enough to hit the rider, but at slower speeds (climbing) they hit more. Hmmmm..some study sure is in order here! And funny how pain-pellets look JUST LIKE ROCKS sometimes on the MTB!

  47. Comment by Lyndon | 07.8.2009 | 1:17 pm

    Hi Fatty,

    This surely now must be elevated to ‘Top Posts’

    On a serious note, I had to buy a new saddle last year and found myself asking the question ‘How does one choose a new saddle?’ I am yet to find a satisfactory answer. Maybe you could apply your other-worldly powers of thought to this and provide some insight….

    With thanks in advance.


  48. Comment by blinddrew | 07.8.2009 | 4:45 pm

    Thing is, not so many hundred years ago, this was science…

  49. Comment by jro_rocks | 07.8.2009 | 5:04 pm

    My Canadian friends have a great synonym for the weave. They call it “Pulling out the snake!” As in, “That hill was so steep, I had to pull out the snake!”.

  50. Comment by McBain_v1 | 07.10.2009 | 5:15 am

    “Pulling out the snake” could land you in serious trouble with the local constabulary here in England. I imagine that should you “pull out your snake” the local plod would then introduce you to several pain pellets that oddly choose to adhere to the business end of their truncheons (the latter being a useful item to encourage you to assist the police with their enquiries).

    I’ve noticed that inclement weather also seems to make pain pellets cluster more heavily, e.g. pi$$ing rain seems to make the concentration of pain pellets on steep slopes more noticeable.

  51. Comment by Penny | 07.13.2009 | 4:43 pm

    I personally have much experience with the pain pellets that inhabit the ground. There is also a strange phenomena that occurs when I encounter the pain pellets on the ground…..my cycling buddy simultaneously laughs, crys and snorts snot bubbles. It’s almost enough to make me want to wipe out on purpose just to experience this, video tape it and win $100,000.00 on AFV.

  52. Comment by caeL | 07.29.2009 | 9:56 am

    Why, if pain pellets are attracted to slopes as balloons are to statically charged hair, do we not encounter these pellets on the way down a slope?

  53. Comment by Col | 09.2.2009 | 12:46 pm

    BikeMike’s comment: “To the pain” Was that from the “Princess Bride?”

  54. Comment by Anonymous | 06.28.2010 | 4:06 am

    i know that some of supertitions beleifs has a basis

  55. Comment by mary grace | 06.28.2010 | 4:08 am

    i know that some of the superstitous belief have a basis


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