Take away all psychological factors, including that 100 or 160 km are round numbers. Also take away that a bike is a transportation device (and hence training for 160 km means one can visit towns 80 km away by bike). What is left is purely the physical advantage. What does someone doing 80-km rides gain from doing 120-km or 160-km rides?

Long Question

Runners take special pride in the length of their greatest accomplishment. They might intone "I've completed half a marathon," or they might sigh with a hint of humility "I have yet to run a full marathon."

Implicit are:

  1. Running 42 km is not "just" more arduous than running 21 km. It leaves the human body in a special (better, healthier, ..) kind of shape, or it takes a special kind of preparation to achieve the milestone.
  2. It doesn't quite matter how fast the course was completed, just as long as the speed resembles running more than walking.

Likewise cyclists will boast "I've completed a century," and perhaps qualify it "metric, not imperial."

What's so special about riding 100 km in a single ride?

Context: I ride 80 km once a week, plus two shorter rides mid-week, and I'm gradually making my way towards 100 km, but I'm not sure what it means, besides enjoying more time on the saddle. I am basically looking for motivation to continue increasing the length of my rides. Completing 100 km or 160 km does make it possible to join clubs that ride for these lengths, but let's dismiss that social factor, in particular since those riding longer distances seldom slow down enough to actually chat. These are definitely keep-up-or-get-dropped rides.

Is the answer identical to the accepted answer at the following question?

In other words, do the benefits of base kilometers not max out at some point? Does, for example, riding 100 km on Saturday and resting on Sunday make you a better athlete than if you rode for 50 km on Saturday and then rode again for 50 km on Sunday?


Chris H says:

If you can ride 80km in a day, [..] you could quite possibly go out and do 160km [tomorrow], [..] but you'd be quite likely to suffer for it.

I am most interested in this closing sentence: “but you'd be quite likely to suffer for it.” If I will suffer after doing 160km tomorrow (despite sufficient nutrition and hydration), but I will not suffer from 160 km provided I work my way up to it, then this means that something changes in the body when one trains for longer distances.

The reason cycling breaks away from running is the following. It may, just may, be the case that only a subset of humans have the genes to run 42 km. But anyone, with training, can cycle for 160 km, again with training. If true, it would be a huge boon to cycling. It means a cycling trainer can tell a budding cyclist:

Unlike running, you do not need to have a genetic makeup that is proto-Olympic. You can cycle 160 km, if you just train for it.

But a running trainer, faced with the aching joints and the limited lung capacity of an aspiring Boston marathon participant may turn them back and tell them “you’re simply not made for it.

  • 2
    "those riding longer distances seldom slow down enough to actually chat" I don't know about clubs, but if I'm out with friends, I'll chat. Sure we could beat some PRs if we acted as a team (and very often we do), but I don't like using people as wind shields.
    – jayded-bee
    Commented Sep 9, 2022 at 3:30
  • 6
    Do cyclists really boast "I've completed a centennial"? It sounds like a normal training ride to me and this is the first time I've read anyone use "centennial" instead of "century".
    – ojs
    Commented Sep 9, 2022 at 10:24
  • 2
    I think I covered that in the edit, but I've got a busy weekend of riding coming up and I should be preparing for it - so I might go a bit quiet for a few days.
    – Chris H
    Commented Sep 9, 2022 at 19:22
  • 3
    Years ago I was young (and stupid), I rode a metric century in 3:34 after more than 8 months of the bike, with no training beforehand (unless a 5km spin around the block the weekend before to check the bike wheels still turned counts). Of the imperial centuries I did, most of my training topped out at 80-100km. If you ride 80km once a week and feel good the next day, the only thing stopping you doing 160km tomorrow is mental state and tolerance for discomfort. Learning to listen to your body and understanding the difference between hard work pain and injury pain is key to long distance
    – mattnz
    Commented Sep 10, 2022 at 0:56
  • 2
    Today I got a train to avoid a familiar stretch but boredom isn't normally an issue. Some days I'm not massively in the mood and maybe there's boredom in that. On Audax events I'm often in company and I have an excellent ride buddy for a lot of the other rides. I too prefer to keep my ears on the road - and to save battery
    – Chris H
    Commented Sep 10, 2022 at 19:48

13 Answers 13


In other words, do the benefits of base kilometers not max out at some point?

The benefits of base kilometers scale up to very high volumes of riding. However most people living normal lives (non professional athletes) have lots of accumulated stress from other factors and are limited by time available and ability to recover.

A perfect example of a high volume of base miles can be found in an excellent article by Nils van der Poel (a speed skater not a cyclist - yet) who used enormous volume of cycling (aimed for 30-35hrs per week zone 2 training during his base phase) to build his base for the olympics: https://www.howtoskate.se

Does, for example, riding 100 km on Saturday and resting on Sunday make you a better athlete than if you rode for 50 km on Saturday and then rode again for 50 km on Sunday?

That would depend on your current level of fitness, your goals and even where you are in your cycling season. Long rides certainly play an important part in developing endurance - some adaptations require your slow twitch muscle fibres to become fatigued and this generally happens towards the end of longer rides.

Personally I don't go beyond 4 hours in a single training ride too often as I generally find pushing to 5-6 hours to be destructive (needing several days to fully recover).

Edit: As requested in comments

I am basically looking for motivation to continue increasing the length of my rides.

As you develop your aerobic base and make adaptations a larger proportion of your energy for a given power output will come from fat stores, which in turn means you are using less of your valuable glycogen stores.

This means you can ride further, or faster, or simply feel more fresh/powerful at the end of a long ride

  • 1/2 I was kind of hoping you would answer the present question by saying, for example, that training for, and completing, 200 km results in glycogen stores that are twice as large as those resulting from 100-km training, and that the latter produces twice those of 50-km training.
    – Sam7919
    Commented Sep 9, 2022 at 16:16
  • 2/2 Re: “I generally find pushing to 5-6 hours to be destructive.“ (As a follow-up to my comment on Chris H's answer, in the body of the question) It sounds like you are saying after all that the process of riding 160 km or more, several days in a row, with only the occasional day break (such as in grand tours) is after all also a process of selection to find who has the genes to do it, in the same way that not every human can run a marathon—not even at the ordinary speed of 10 km/h as opposed to the superhuman speeds of race winners.
    – Sam7919
    Commented Sep 9, 2022 at 16:17
  • @Sam training for a 200km ride wont double the size of your glycogen stores. BUT, the adaptations you make might allow your stores to last twice as long at the same power output. That's how the pros are able to put in huge performances at the end of long days - they have amazing fat oxidation rates. We will never be pros, but regular long endurance pace rides can allow us to see some of the same benefits
    – Andy P
    Commented Sep 10, 2022 at 20:42
  • I don't think you're saying that energy can be produced out of nothing, but are you saying that if my cycling computer tells me now (however inaccurately) that a given, say 80 km, ride uses, say, 2000 calories, and, after three years of regular training, it continues to tell me the same number for the same ride at the same speed (how would it know better?), then it will be lying after three years of training, because the adaptations I made would enable me to complete the same route with fewer calories?
    – Sam7919
    Commented Sep 11, 2022 at 13:27
  • @Sam no, for a given power/intensity you will always burn the same number of calories. The difference is where they are burned from. As you develop your aerobic base and make adaptations a larger proportion of your energy will come from fat stores, which in turn means you are using less of your valuable glycogen stores.
    – Andy P
    Commented Sep 12, 2022 at 7:40

If you are doing 80 km once a week right now, I have absolutely no doubt that you can do 100 km tomorrow, if you want to.

What's so special about riding 100 km in a single ride?

Here are some reasons to set yourself a goal of some specific distance (such as 100 km):

  • You have an upcoming ride of that distance (maybe a ride with friends, or a club, or even a race) and you want the confidence of knowing you can complete the distance.
  • There is somewhere specific you want to go, or a specific route you would like to ride, which requires a longer distance.
  • You want to take pride in your accomplishment, and telling friends/family that you "rode a centennial/century" (or for non-cyclists, "did a 100 km ride") is an easy succinct way of telling them what you have done.
  • Humans like nice round numbers. 100 is round.

The ability to ride 100 km does not necessarily mean that the rider is in any special kind of shape or has done any special preparation steps. I believe almost anybody who regularly rides more than an hour or two at a time can stretch that out to 100 km.

  • 1
    In other words: If you plan your own routes, a target distance (and climb) makes for a good way of assessing whether how long it will take, and the state you'll be in afterwards. If you don't, and like to do events, these distances are popular (then you'll know what they feel like if you do start planning your own routes). +1
    – Chris H
    Commented Sep 9, 2022 at 12:24
  • The last point is very significant. There’s a reason that most races, cycling or not, are either between specific landmarks (this is actually how marathons started), or are nice, easy to understand numbers, and it has little to do with anything other than human psychology. Commented Sep 9, 2022 at 13:25

100km is a nice number and it demonstrates that you have put time in to cycling a decent distance. Not everyone wants to put enough time into cycling to achieve a 100km ride, even though my belief is that most people who cycle regularly and have good fitness could complete a 100km ride if they ride at a suitable pace and are prepared to feel a bit stiff the next day.

An imperial century (100 miles) is much more of a milestone, at around 160km, and requires considerably more physical and mental stamina, preparation, fuelling and hydration, not to mention the additional time taken to train and then make the ride. Many people who prepare for 100 mile rides (eg sportif events etc) find the weakness in some aspect of their preparation begins to show towards the end of the day: it is much easier to fail at this distance.

In answer to your new TLDR: The main benefit, if you are not competing or training to compete, will be a scale benefit. Your body and mind are trained for longer rides: shorter rides become easier, faster and perhaps a more common event in your life. Effects on your overall health, fitness and enjoyment of life may not be so easy to measure.


People like to get achievements that others can understand. The actual number is pretty arbitrary - in the case of a marathon, the reasons are more mythological than historical, but that's a sort of upper limit of normal (and as someone who's never run much more than 10km,it seems like a very long way to me).

The numbers are a bit tidier in cycling but the concept is the same, to the extent that an imperial century is regarded a bit like a marathon. A good chunk of a day riding is very different on the body (mainly the joints) to a similar time running. In both cases a random beginner would think that's an awfully long way.

No one has to go for distance though. Plenty of riders are much more interested in much shorter, faster things. Some of us find ourselves more suited to going a long way steadily than going fast, and might not be competitive - we need distance events to satisfy us.

It's certainly possible to do that kind of distance at a sociable pace. Most people riding Audax/randonneuring will settle into a loose group for a bit, or even the whole ride, and that's a setting where 100km is a starter distance and 200km typical. I've done an event where we rode as a team for 24 hours only stopping for food, chatting off and on much of the way. Of course there are others who want to get round even a very long event as quickly as possible; even beyond that, ultra-racing exists.

Long distance events use a slightly different fitness to shorter, faster, events. If your goal is to complete a century, just working up to it will do. If your goal is to get a good time, building the distance on fast rides is likely to be needed.

If you can ride 80km in a day, or 2x50km in a weekend, you could go out and do 100km tomorrow.* You could quite possibly go out and do 160km, especially if you also have a midweek ride or two - but you'd be quite likely to suffer for it. You'd also suffer if you ran double your regular maximum, but in slightly different ways. Both will give muscle aches and pains, and overall fatigue (which I found crippling the day after quite a few rides as I grew my 1-day distance). Running will stress your joints (I had to increase very gradually from 5km to 10km for the sake of my knees, and that's common). Cycling shouldn't, barring poor bike fit. Doubling your distance suddenly will more than double your saddle time and that will place demands that you're not used to on your seat area, hands/forearms, and back. When I got home from a particularly long weekend's riding (Strava link for which you either need to be following me or logged out!) earlier this year, I couldn't even stand up straight until the next day, my back was so weak and stiff.

I suspect that the proportion of people who can run 10km and could train up to a marathon, and the proportion of people who can cycle 50km and could increase to 200km, will be pretty similar. In both cases that's approximately a 4x increase, rounded to the nearest popular distance. They might take lot of training to do so in both cases, but the barrier is likely to be one of desire to train for most people. I say nothing about speed in that. The runners have it slightly harder, so I'd expect a slightly higher rate of people who for reasons like historic injury couldn't do it, and some would need additional exercises/support from a physiotherapist (more so than for cyclists). In other words I don't think there's any more of a genetic limit on running to cycling, when speed is taken out and we consider the ability to just keep going.

* But expect to need more additional calories and water than simple extrapolation would suggest.

  • BTW I also ride multiple hundred km solo. That's a different experience again, and one which I deliberately left out of the answer as the social aspect seems to matter to you
    – Chris H
    Commented Sep 9, 2022 at 6:30
  • To simplify a point I made in the answer: you don't have to ride further than you want to.
    – Chris H
    Commented Sep 9, 2022 at 12:29
  • I first added comments here, but that's really the crux of what I am looking for. Hence I added the comment to the body of the question instead.
    – Sam7919
    Commented Sep 9, 2022 at 16:07

No one has actually said in it any of the current answers, I argue it does not matter. What matters to people is personal, and the more un-important it is, the more personal it is if it matters. It is not like we are discussing why access to clean water and food matters.

Riding a bicycle is pretty un-important is the scheme of life, so how much it matters is highly personal. For a vast majority of the population, it does not matter. For probably most cyclists, it does not matter (those that don't care about long distance, and those that do care and ride it every week month).

George Mallory was once asked why he wanted to climb Mt Everest. His answer sums these things "Because it is there".

  • This. So much this. Commented Sep 12, 2022 at 5:38

Competitions and personal bests: People just like to challenge themselves, set goals for themselves and boast about their achievements.

For some people riding 20km is already hard and they’ll be proud of their achievement. For other people a 120km ride is just another long and boring training session.

Of course distance alone doesn’t tell you anything about the conditions (speed, weather, elevation change, equipment, traffic, drafting …).

Training: There are some benefits to long and easy training sessions, but the definition of “long” and “easy” depends on the individual and length should be measured in time, not distance.

Utility: For me personally the biggest benefit of being able to ride long distances is that it makes certain trips much easier or enables them in the first place. From simple transportation like going to a climbing crag 30km away or visiting my aunt 40km away (in both cases you want to arrive fresh and relaxed and have to go back home) to full blown bike travel where being able to ride >100km every day with 12kg of luggage makes it possible to cover much more ground and see more things.

For me that’s the biggest difference between running and cycling. When I was still able to run I much preferred shorter (5–20km) distances because they are more fun and being able to run 50km without a break doesn’t offer any utility or benefit. I don’t understand why everyone wants to complete a marathon, often needing 4 hours or more and even walking some parts when they could just run 7km at an all-out pace and truly feel alive.

  • 1
    Training: I'm often asked by friends/colleagues "how far did you ride" and they seem quite baffled when the answer is "4 hours easy". Outside of completing specific events I very rarely have any interest in the actual distance travelled.
    – Andy P
    Commented Sep 9, 2022 at 7:06
  • 3
    @AndyP and that's the difference between training goals and distance goals. Riding 4 hours at specific intensities is training towards a goal which is likely to be winning a race (if you race, you have an ambition to win, we hope!). Training for distance is much more simple in that regard, and the distance travelled is psychologicallymore important.
    – Noise
    Commented Sep 9, 2022 at 8:24
  • I'm not sure if hours are the really good indicator of effort for road riding. The same 100 km can be serious effort if you do it solo under 3 hours on non time trial bike, easy ride at 4 hours and any longer means that you probably had a break or few.
    – ojs
    Commented Sep 9, 2022 at 11:43
  • 1
    @ojs The point is you never go out to ride 100km. The distance is irrelevant. You go out to ride X duration at Y intensity. 4 hours at 150W is 4hrs at 150W regardless of if I travelled 70km or 130km
    – Andy P
    Commented Sep 9, 2022 at 12:01
  • @AndyP I don't have a power meter so all wattage numbers are going to be imagined. On the other hand, I usually plan to ride a specific route that has an actual length.
    – ojs
    Commented Sep 9, 2022 at 15:25

For another perspective, sports should ideally have an achievement ladder with goals that are not too far apart in difficulty. Imagine that running's marquee distances were 10km (6.2 mi) and the marathon (42km/26.2 mi), and there were no intermediate distances. There's quite a large gap between the two events. Someone just getting into the sport who relied on organized runs for their motivation would have a big gap after completing a 10km rim.

Similarly, a 100km/62 mi distance is quite challenging for many cyclists, and it offers a stepping stone before an imperial century. When planning an imperial century route, it's often possible to find a shorter one that's about a metric century, e.g. the Tour de Tonka offers 71 and 42 mile rides (and three shorter distances). Unbound Gravel initially started as a 200-mile ride/race. I believe that in 2019, it had a 50-mile and a 400-mile (!!) option, but no intermediate distances. In 2022, they added 100 and 25-mile distances.

In a similar vein, professional road cycling does attempt to offer lower-difficulty races where less advanced pros can attempt to shine. One of the problems in the pandemic was that the less prestigious races were more likely to cancel, which left Pro Conti and lower level riders in the lurch as top riders started competing for the remaining races. There are separate Under 23 and Under 18 classifications for younger riders, the theory being that endurance athletes often take some time to hit full potential.


Your question caught my eye as it really hit home.

I have completed several (metric) centuries this summer (with the help of my local club) but these days, I no longer feel the incentive to go for longer rides. As you, I am quite happy going for several shorter (50-80km) rides during the week.

Back to your question, I think that the completion of a century matters for a lot of people as it is a very common goal that they set themselves to provide motivation to continue riding, which is, in the end, the important thing in my opinion.

From the way you formulated your question, it is clear that it is not the right goal for you so you can pick another one (go on a bikepacking trip, visit a faraway friend by bike, do a mythical climb...)

Do whatever makes you happy :)

  • 2
    +1, whatever makes you happy. I got very happy completing a very wide circle around Hamburg with a little more than 300km within one day on my recumbent. I also got happy riding "only" 60km, but with an average about 45km/h. I also get happy carrying my MTB up 1500m just so I can ride down for more than an hour. For me it's all "Wow, didn't know my body could do that".
    – arne
    Commented Sep 12, 2022 at 10:31

enjoying more time on the saddle

For me this should be the main qualifier! If you lose the enjoyment of riding after eg. 80KM, then just don't.

Sometime it can be fun to push yourself beyond the enjoyment in the moment such that you can enjoy the feeling of accomplishment afterwards. For me that's also a valid reason to increase the ride. Some people call this Type 2 fun. If you don't enjoy that either, just don't go beyond your natural limit!


Having done about 100 km yesterday, to collect my cycle (velomobile) from the place best suited for repairs. In this case I have had to ride my VM there one week to go and collect it the next. My top distance for now is 120 km.

A lot of people who ride the same kind of cycles do longer distances and can go for a small repair or to collect parts in one day, going there and returning in one day.

I try to build up my ability and where last year I needed more than a day to get my VM there, this year I could do it in a day. Maybe next year I can do so much more that I can bring it in the morning and in the evening cycle on to a nice hotel (not much available close to it.) And in two years I might be able to do the full 200 km in one day as well.

So you see, I set myself a target and hope to meet that in time, but not to compete or even to post the results, but to be able to meet my personal needs.


Giving the impressions of an overweight bloke approaching 60.

Completing a century is just a natural goal. I did it with friends back in '79 as the first day of a tour we had planned but had to call off after I crashed on day six. I restarted semi-regular riding in '18, (to support some dietary changes I had made) and gradually increased the distances. Then finally, on July 5th,2020 I managed it again. I did not enjoy hours three and four very much, but then it got a bit better (may be the first snack didn't help, but the second did). You may wonder about the strange loops near the end, but...

Nobody's gonna report back to friends telling that their longest ride of the season was 96k, right :-)

My average speed has improved very slowly or not at all. That may be because even on my usual two hour / 45 km rides I don't constantly strain myself. My lower body muscles have never been strong, and that shows in other sports, too. I don't know why that is so. I ride by myself, and mostly to consume calories and to watch the seasons tick by all around my home county.

A nearby club organizes annual 60/120/250 rides. May be one year I will be prepared to join them on that 120? At this age the goals need to be realistic.

Happy pedalling to all!

  • 1
    I know that "if it's not on Strava, then it didn't actually happen." I also know that much of what we do is driven by what we can demonstrate on this or that social network. But I'm actually much more interested in why someone would ride a century in 1979. In a pre-Strava era, surely no one would pick up the phone, call friends, and tell them they had finished a century. People did it, and, especially, they repeated it many times, for concrete physical gains. What are the gains obtained from a 120-km ride on one day that couldn't be obtained from two 60-km rides on consecutive days?
    – Sam7919
    Commented Sep 12, 2022 at 5:54
  • 1
    @Sam. In '79 the reason was that the first planned camp site along our route was 102 km away. I know, it is silly, really. Call me a compulsive numerologist! Commented Sep 12, 2022 at 6:00
  • 1
    Yes, yes, but focussing on 100 should be left to "just" homo-sapiens numerologists, as opposed to homo-sapiens + aliens of-all-stripes numerologists—the latter do not in general have ten fingers. Hence if we focus on just the accomplishment, rather than on the boasting, then a saner approach, driven by the fact that it's easy to increase the distance slightly but rather hard to double it, is to accomplish 32 km, then 64, 128, and 256. Call me a bits-and-bytes creature with no more than two digits.
    – Sam7919
    Commented Sep 12, 2022 at 6:07

OP here. I can summarize the benefits of increasing one's rides to 100-km from 80-km as follows:

  • First and foremost, it is a test of willpower. If you're an amateur, nothing forces you to finish, and there will be a voice in your head that starts to nag you at some point luring you to go back to enjoy the (already well-deserved) nice meal and fruit juices.
  • Leg muscles become thinner yet, oddly, stronger. This is just an impression, and it may be a placebo effect. If you haven't done it yet, it may be a good idea to keep a record of the circumference of your calf muscles.

Some future questions are:

  • Do you see continually increased benefits when you gradually raise the distance traveled in one trip—to 120 km, 140 km, and then 160 km?
  • Riding longer distances typically invite a day of rest—or at most a short-distance, low-intensity ride. (If we still keep all psychological factors such as boasting and pride out of the equation,) are there benefits to pushing oneself to do two centuries two days in a row? Do the benefits start to have a chaotic element to them, as we can surmise from even the most elite athletes commenting after a stage-race "let's see how I feel tomorrow"?
  • The standard answer to "how can I complete my 20-km ride faster?" is to ride longer distances (at lower intensity). What, then, is the way to complete 100-km faster? Is it to do 180-km, or 250-km (at lower intensity)?

Eddington Number

This is a measure of your participation as a cyclist over the course of your life. It does not measure speed, performance, or any other skill, just that you accomplished this goal.

Your Eddington number cannot decrease, ever. As such it is another comparable metric that does not require power, just doing the rides.

(Arthur) Eddington is credited with devising a measure of a cyclist's long-distance riding achievements. The Eddington number in the context of cycling is defined as the maximum number E such that the cyclist has cycled at least E miles on at least E days.

For example, an Eddington number of 70 would imply that the cyclist has cycled at least 70 miles in a day on at least 70 occasions. Achieving a high Eddington number is difficult since moving from, say, 70 to 75 will (probably) require more than five new long distance rides, since any rides shorter than 75 miles will no longer be included in the reckoning.
Eddington's own life-time E-number was 84 (miles)

The Eddington number for cycling is analogous to the h-index that quantifies both the actual scientific productivity and the apparent scientific impact of a scientist.

From https://en.wikipedia.org/wiki/Arthur_Eddington#E_number

Personally my Eddington number is 73 in kilometres, meaning I have ridden 73 rides of at least 73 km. I need four rides of 74 km or more to increase my number by one. Clearly some of my rides were exactly 73 km long and no longer contribute for a 74 km goal.
My number in miles is only 48.

  • 1
    This is wild. I have no idea what my Eddington number is. Strava should add it.
    – SamA
    Commented Oct 27, 2022 at 13:15

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