Long Distance Competition/Ultracycling, Randonneuring and Endurance Cycling - Centuries are easy -- here's how

A century ride is one of the easiest rides which almost any cycle rider can do without much training.

A number of riders have expressed their intention of completing a century this summer as though it were the ultimate accomplishment and that they were in intensive training to reach that goal. Some have mapped out a plan of increasing their distances each week on a regular basis until sometime in late August or early September they finally ride a century.

At the risk of being branded a fanatic, let me say that such a training pattern is actually counterproductive. If you have ridden a ride of 40 or 50 miles, you are already capable of doing a century. However, there are a number of factors which might make you think that a century is impossible at this time. Perhaps I can enumerate a few things which might help you do a century sooner than you had anticipated.

1. A century is a distance which stretches your mind more than your physical strength. If you can ride 40 or 50 miles you have the physical strength to ride 100 miles. It is the thought that this is a formidable distance that needs to be overcome. Lots of people (not just the strong athletic types) have done a century with very little training.
2. Be sure your bike properly fits you. Although you could do the ride on any bike, you will be more comfortable on one that is fitted to you. If you don't know if your bike is the proper fit, get in touch with a good bicycle shop or members of a local cycling club.
3. Forget about those riders who tell you that they completed a century in under five hours. Plan on a ride of ten or eleven hours. In the future you can try for a sub-five century; but for your first century, aim to complete it at a reasonable average rate of about 15 km/hr (10 mph).
4. Map out your ride by riding 50 miles to a particular town and then back again. This is a preferable ride than a circular route. When you arrive at that town, stop at a food place for something to eat. On my first century, I kept thinking about the ad which offered two big hamburgers for $5.00 -- I could hardly wait to take advantage of that bargain. I like to spend 30 min. or more relaxing with my lunch.
5. Start your ride at 8:00 am. You will probably arrive at the 50 mile town around noon.
6. Be prepared with the right equipment: two water bottles (one with Gatorade and the other with plain water); a couple of energy bars (I like fig newtons); a small tool bag with minimal tools; a cell phone for dire emergencies and to call home to say you have reached 50 miles and are planning to come back.
7. Take sips of liquid frequently. You should finish at least three-quarters of your liquid by the 50-mile town.
8. Wear the right clothing: padded cycling shorts, wickable jersey, helmet, cycling gloves, jacket if necessry, tights if necessary
9. Use sunblock
10. Use a good lotion to prevent crotch and butt rash.

Perhaps there are some things I forgot to mention. Those of you who ride lots of centuries, perhaps you could add a few items.
For those of you who are not "century believers," you might want to give it a try before you respond negatively.

A century ride is one of the easiest rides which almost any cycle rider can do without much training.

A number of riders have expressed their intention of completing a century this summer as though it were the ultimate accomplishment and that they were in intensive training to reach that goal. Some have mapped out a plan of increasing their distances each week on a regular basis until sometime in late August or early September they finally ride a century.

well, just as a slight rebuttal -- you're talking about being able to do a DIY century with little or no training, and I would partially agree. Anyone who's comfortable with 50 miles can probably do a 100 if they back off on their average speed, pace themselves properly, eat appropriately, and have the luxury of picking a pleasant route.

What's worth pointing out, though, is that a lot of folks who posted here asking for help either a) have just started returning to riding and still haven't gotten to the point of being comfortable with 50 miles yet and/or b) are planning on doing an organized century. So they don't get to pick their routes. The most frequent rookie mistake that I and other friends had committed was undertraining and, say, just riding a lot of flat miles without climbing. Then we'd get surprised by all of the hills that we'd have to do. Training up to being able to ride 70 miles, instead of 50, imho, gives a beginner an extra cushion of conditioning to offset the fact that we might naturally train on easier terrain.

Otherwise, yeah, it's more of a mental challenge than a physical one -- which is why the other piece of advice that we've given to folks is to break the ride down into smaller pieces and just focus on completing each piece individually. It's not a 100 mile ride. It's ten 10 mile rides. Or four 25's. etc.

Great advice, and even though I have not rode a century yet, I plan to commit several of your elements to my plan. I will be riding at least one more metric before I do the charity ride century and did one a few weeks ago.

I do however think your liquid recommendation is low. I would expect to refill the water bottles at least twice in 100 miles... For a total of 6 bottles of fluid for a 100 mile ride. There should be plenty of places to refill.

If a rider gets to the 50 mile point without emptying two large bottles at least once, I think that most riders would be dehydrating.

Again, thanks for the advice!

I do however think your liquid recommendation is low. I would expect to refill the water bottles at least twice in 100 miles... For a total of 6 bottles of fluid for a 100 mile ride. There should be plenty of places to refill.

If a rider gets to the 50 mile point without emptying two large bottles at least once, I think that most riders would be dehydrating.

Again, thanks for the advice!

The general recommendation is one 750 ml bottle of water and/or sports drink and/or other beverage every 1 to 1.5 hours, depending on the weather conditions and the amount of effort you are putting in.

So if your century takes you 8 hours, you should aim to have downed approx. five 750 ml bottles (unless it is really hot or windy, in which case you might want more) ... for a grand total of about 4000 ml (4 litres).

Now I also count the tall glass of apple juice or whatever I drink before the ride in that total. So how it tends to end up working for me on a century is that I drink about 500 ml just before the ride, plus about three 5-600 ml bottles of something which I might pick up at a convenience store, and which I'll drink while I'm standing or sitting at rest stops along the way. All that adds up to about 2000 ml (2 litres). Then I get the rest from my bottles. Each of my bottles is about 750 ml, one contains water, and the other HEED. I usually empty the water one once throughout the entire ride (not fond of plain water), and the HEED one approx. twice.

I will take several exceptions to the OP's recommendations:

1. Giving any hard guidlines regarding how much fluid to drink is dangerous. In Texas, you would need quite a bit more than 2 bottles/50 miles on a summer day.

2. An out and back ride is no easier or harder than a loop. Many people, myself included, enjoy loop rides more than out and back routes. A better strategy is to map out a route that avoids difficult hills, passes evenly spaced convenience stores, avoids heavy traffic, has interesting scenery, etc.

3. Setting speed averages without knowing the rider is not a good idea. A better strategy is to use a herat rate monitor to determine ones exertion level for 80-85% of MaxHR and try to average this heart rate during the ride. The idea is to ride in a manner that conserves glycogen so a bonk is less likely.

4. You do not stress calorie intake except to recommend a bottle of gatorade and a couple energy bars. this is insufficient calories. A person who has done no more than 50-60 miles is a prime candidate for bonking on a long ride and should be taking in ~250 cal/hr.

Your basic premise that a person in reasonable conditioning can do a slow century is sound. And your recommendations regarding equipment, bike fit, and clothing are also good for century riding, as well as any riding.

Another recommendation for the novice century rider is to take frequent breaks and to stretch muscles to help avoid cramping. In hot weather, taking breaks at stores allows one to get inside some air conditioning to help cool the body down. This may not be a big deal in Alberta, but in Texas and most of the Southern US, heat exhaustion and heat stroke are serious dangers on long rides - especially for someone who has never done a century - as much of the riding must be done in the heat of the day.

Yep, before I completed my very first century (100mi), The Solvang Century many years ago, my longest ride ever up to that point was only 50 miles....

2. An out and back ride is no easier or harder than a loop. Many people, myself included, enjoy loop rides more than out and back routes. A better strategy is to map out a route that avoids difficult hills, passes evenly spaced convenience stores, avoids heavy traffic, has interesting scenery, etc.


Most people like to have a target. Going 'somewhere' and back is a good way to do a ride, otherwise you might as well ride round your block 1500 times. I've found that a loop route usually gives too many opportunities to shortcut when you are going through a bad patch...

3. Setting speed averages without knowing the rider is not a good idea. A better strategy is to use a herat rate monitor to determine ones exertion level for 80-85% of MaxHR and try to average this heart rate during the ride. The idea is to ride in a manner that conserves glycogen so a bonk is less likely.


This is an interesting point... I have never considered using a HRM for a century, but now I may.

However, it would seem that 80-85% average for 5-8 hours for someone used to a significantly shorter distance might be riding pretty hard. Do you really advise riding in that range for a first century rather than allowing for a more casual pace? If so, why?

It would seem like a hard mental challengeto ride 50% farther at a pace that is possibly as fast as (or faster than) the previous long ride of say 70 miles.

This is an interesting point... I have never considered using a HRM for a century, but now I may.

However, it would seem that 80-85% average for 5-8 hours for someone used to a significantly shorter distance might be riding pretty hard. Do you really advise riding in that range for a first century rather than allowing for a more casual pace? If so, why?

It would seem like a hard mental challengeto ride 50% farther at a pace that is possibly as fast as (or faster than) the previous long ride of say 70 miles.

I suggested 80-85% because 80% of MHR is the typical heart rate recommended for "aerobic" exertion levels where you are predominately burning fat for energy. this also allows for the typical increase in heart rate trying to maintain speed going up hills.

However, the main point is that a person should determine a sustainable heart rate for them and try to maintain that heart rate.

I dunno

I can can do 40-50 miles before breakfast without any problem (and do this a few times a week), but I still find 100 miles to be difficult. I dont know if its my age (40), bike fit or saddle, but my lower back and butt start to ache enough at 80 miles to want to call it quits.

In hot weather, taking breaks at stores allows one to get inside some air conditioning to help cool the body down. This may not be a big deal in Alberta, but in Texas and most of the Southern US, heat exhaustion and heat stroke are serious dangers on long rides - especially for someone who has never done a century - as much of the riding must be done in the heat of the day.

As a Texas rider, I have often used one water bottle just to keep the jersey wet and cool down the core body temp. If the skin gets prickly and dry, its time to pull over. Even on a shorter ride in the heat of summer, I often carry extra water in a rack pack or just wear the camelback. My theory is that you can't have too much water in the summer.

I dunno

I can can do 40-50 miles before breakfast without any problem (and do this a few times a week), but I still find 100 miles to be difficult. I dont know if its my age (40), bike fit or saddle, but my lower back and butt start to ache enough at 80 miles to want to call it quits.
So do mine, but at about the 87 mile point, but shortly after the ache hits, I get the endorphin load and off I go so far for another 50 easily! My first and second century+ rides were accidental! I'd gotten so "in the zone" that I didn't really even think about the miles I was riding, I just rode them! I'm looking at a double century this August and am planning it in about a 15 hr period.http://www.yatoula.com/gif/smiley_2/smiley_853.gif

Centuries (and longer) can sometimes be tedious, tiresome more than tiring for me.

There are lots of different kinds of centuries. They are not all created equal so you can't say riding a century is easy. Some are some aren't. Depends on conditions, terrain, bicycle etc. I can assure you that a century here in Kansas today with the current temp at 103 F, would not be EASY!

Albany,
My guess the problem is with your bike fit.
I am 64 and find no problem doing a century.
I am not fast. I take my time and enjoy the ride.

I dunno

I can can do 40-50 miles before breakfast without any problem (and do this a few times a week), but I still find 100 miles to be difficult. I dont know if its my age (40), bike fit or saddle, but my lower back and butt start to ache enough at 80 miles to want to call it quits.

Have you got yourself a Brooks saddle yet? I think the saddle is one of the first things you need to check. You see ... several years ago, my good ol' cheap-but-comfortable saddle broke, and I was forced into the position of hunting for a new saddle. I knew about the Brooks, but thought they would be painfully hard to ride on, so I tested a bunch of different saddles.

One saddle I tried was the Selle Italia Ldy ... and I could hardly imagine a more painful saddle. It wasn't so much that it was uncomfortable to sit on - I could do shorter rides fairly comfortably - it was that my lower back was in PAIN!!

I analyzed all the comfortable saddles in my past, and realized that they all curved up in the back. The flat saddles offered no support, it felt like my back was just hanging there. With a curved saddle my back could rest.

Now I know that the Brooks looks flat when you get it out of the box, but it will curve. Whether you end up with a Brooks or not, you might consider a different shape of saddle and see if it helps.


As for your age ... when it comes to long distance riding, 40 is a mere baby!! The average age on the PBP in 2003 was 49 years old. There were a lot of riders between about 45 and 55, but there was also a significant number over 55 ... all the way up into their 80s. So ... age is no excuse!! :D

And BTW - I'm 39 ... and I'm one of they younger randonneurs. :)

I also don't think that you have to ramp up the distances too high - you need to focus on quality miles rather than quantity miles. However...

1) You need to have at least a couple of 4 hour rides under your belt before you go for the century, so that you can get your hydration and nutrition plan working well.

2) 85% of HR max is *way* too high for even trained riders. My training (Carmichael-based) puts my endurance training zone from 50% to 85% of my 3 mile TT heart rate average. That puts the high end of my aerobic range at about 82% of my max. My "ride forever" HR is closer to 120, or around 70% of my max.

I do like the concept, however. Unless you've trained in HR ranges, it can be hard to limit yourself to a specific heart rate range.

3) I don't see a lot of point doing your first century self-supported. It's a lot nicer not to have to carry all your food, to have mechanical support if you need it, and the chance to find somebody to pass the time with.

4) Don't spend a ton of time resting. The amount of time it takes for your legs to stop hurting when you restart is roughly equal to the amount of time you spend stopped.

3) I don't see a lot of point doing your first century self-supported. It's a lot nicer not to have to carry all your food, to have mechanical support if you need it, and the chance to find somebody to pass the time with.



Sometimes you've got no choice!

I did my first century self-supported ... and also about 90% of them since. Counting it up, I've only had maybe a dozen supported century-or-longer rides.

It can be nice to have support, if the support is done correctly. I've been on several century-and-longer rides where it was not.

The local century in Winnipeg, for example, used to be a really well supported century, then the last few years I rode it, the level of support dropped right off. When I first started riding that one, I would have recommended it as a "first century" event for any cyclists who had not yet done a century, the last couple of years I would not have recommended it for anyone who was not fairly well experienced at centuries. What began to happen in more recent years with that one was that the racers would come out and ride it, and the volunteers and rest stops would cater to all the fast riders.

Everyone (volunteers, ride organizers, etc.) would all pack up and go home by 7 hours ... so if you were still out on the course after 7 hours, tough luck. The one year I rolled it just before the 7 hour mark ... everything was all packed up and they were all about to leave ..... and I had to practically beg the support crew to drive the course backward to see if there were other cyclists out there. I knew there were a couple dozen still behind me, but the support crew kept trying to tell me I was the last one out there. And as for the food at the rest stops, because they expected everyone to ride fast, the last 20 or 30 of us got nothing. The food was all gone! In one case, even the tables and tents and everything were completely gone ... packed up and driving away as I rolled up!!



Personally, I think I'd rather do a self-supported century as my first (which I did) because I could do all the planning and there would be no pressure to ride faster or to eat unfamiliar foods, etc..

I didn't eat well on my first century ... I didn't know about the 250 calories/hour thing back then ... so the biggest thing I'd recommend to new century riders is to eat 250 calories/hour all the way through the century. But I think my choice of route was a good first century route.

I don't remember the exact details of it, but I know that it started by going from my house (on the edge of the city) into the city toward the downtown area, through a park and along a scenic route next to the river. That was a route I often rode in the evenings so it was familiar to me. Then I returned and cycled past my house out of the city to the next town down the road. That was another route I often rode in the evenings. Then I headed back into the city, past my house and back into the park, but by a different route, through some other neighborhoods. And I kept doing that (approx. 4 entire loops) until I was done. I stopped at my house a couple times to use the toilet and grab something to eat, which was very convenient ...... and the really nice thing about the whole route was that it was all familiar to me, and at no point did I feel like I was stuck out in the middle of nowhere with the possibility of being forced to fight my way back or anything. I knew that if I really ran into some kind of trouble I could stop. And with that knowledge tucked away in my mind, I kept going and rode my first century. :)

3) I don't see a lot of point doing your first century self-supported. It's a lot nicer not to have to carry all your food, to have mechanical support if you need it, and the chance to find somebody to pass the time with.

There actually some advantages in doing a long ride on your own.

Doing your own ride lets you choose the route. Many organized rides may seek out some extreme terrain in the area to help attrack riders with the challenge of riding up "Killer Hill". By setting your own route, you can choose to bypass Killer Hill if you like.

By setting your own route, you can usually route yourself past convenience stores at regular intervals so you need not carry excessive food or liquid.

Riding alone allows you to more easily stick to your plan and not overexert yourself. In organized rides, there is a natural tendency to ride harder to keep up with others. However, riding self-supported doesn't require you to ride alone. If you are in a cycling club, you should have little difficulty finding another rider to join you.

I don't see why a century ever needs "supported." I've never ridden anything but solo. I stop a couple times to refill drink bottles, and maybe grab a piece of fruit. I carry bars, etc. on my person.

As someone else said on this thread, I too did my first century (after a lapse of a few years) somewhat inadvertently.
I planned on a Saturday ride to a town about 35 miles away and back.
When I go there, I figured it was only another 15 miles to the next town at 50 miles and I could simply limp back home if I had to.
I was ready for 70 miles, so another 30 (I argued with myself) should be icing on the cake -- and it was.
Since then, I have done several centuries out to that town and back as well as 200km and 300km brevets.
Now I think of a century as a training ride for a brevet.

Lest I be misunderstood, I need to point out that I am 64, overweight, and I have never been a sports jock.
I am an average couch-potato with a somewhat sedentary job.
But I love to cycle.

I feel kind of silly replying since I've only riden one century (so far!). I had never riden more than ~40 miles before, and had never riden a loaded bike, but it was still much easier than I thought it would be. That's not to say it was easy, but I didn't feel any pain that day, and was only a little sore the next day. We took our time, stopped for a long lunch, and kept a relaxed pace. I have to agree with the OP that the barriers are largely mental.

Next week I'm doing another century (http://www.bikeforums.net/showthread.php?t=211063), perhaps my opinion will change!

I don't see why a century ever needs "supported." I've never ridden anything but solo. I stop a couple times to refill drink bottles, and maybe grab a piece of fruit. I carry bars, etc. on my person.

My experience as well.

Can your body really make use of anything you eat at the halfway mark? I know it takes around 12 hours for your stomach to clear itself after a large meal, so does eating anything after the first hour really make sense?

Can your body really make use of anything you eat at the halfway mark? I know it takes around 12 hours for your stomach to clear itself after a large meal, so does eating anything after the first hour really make sense?
in a word: yes.

Obviously it depends on the pace that you maintain, as that will determine the number of calories that you will be burning. But, in general, for me, almost anything that I eat in my stomach will fuel me for 15 miles (30, if I really push it and don't care about bonking). So, that's the interval at which I remind myself to eat something. Also, keep in mind that when riding, it's better to nibble often rather than gorge infrequently. Even if it takes 12 hours for your stomach to clear a meal, it will usually process and metabolize the calories at a much faster rate. That's why you get hungry at noon rather than 12 hours after you've head breakfast.

great post. i'm the guy who's always, "dude, you'll never make it" ... but mostly because there's some time limit or ridiculous speed goal. at my first organized century, they were tearing down all the concessions when i got to the finish.

so yes. planning to go out at a reasonable, easy to moderate pace is key 'specially if 50 miles is what you've put in. the sense of accomplishment at the end is worth it.

Can your body really make use of anything you eat at the halfway mark? I know it takes around 12 hours for your stomach to clear itself after a large meal, so does eating anything after the first hour really make sense?

Eating during the ride mantains a base level of calories so that at the end of the ride you have enough energy to eat and sleep or your body will be to weak to recouver correctly ,, also you should drink enough water before the ride --the night before and in the morning so that your urine runs clear , that way all the waste products and toxins are out of the body and don't run to the muscles as your body slowly dehydrates at the beginning of the ride ---- the national cycling team also states that you must eat within 2 hours of heavy exercise or your body will just eat itself - the muscles-- to stay alive

suggested 80-85% because 80% of MHR is the typical heart rate recommended for "aerobic" exertion levels where you are predominately burning fat for energy.

Not true, aerobic burns glucose, fat burn zone around 55-65% burns primarily fat.

Can your body really make use of anything you eat at the halfway mark? I know it takes around 12 hours for your stomach to clear itself after a large meal, so does eating anything after the first hour really make sense?

It most certainly does NOT take 12 hours for food to clear from your stomach. It is anywhere from 20 minutes to 2 hours. Food may be digested slower during periods of exertion because much of your blood is diverted to your muscles, but it doesn't take 12 hours to clear.

Can your body really make use of anything you eat at the halfway mark? I know it takes around 12 hours for your stomach to clear itself after a large meal, so does eating anything after the first hour really make sense?

When I'm worn down, I can feel the energy coming back within 15 minutes after eating. I don't know where you got 12 hours from.

Did a century on Friday!

First century for me in about 20 years - when I did two centuries back to back on a Toronto - Montreal trip.

Funny thing - the first 70 k was MUCH harder than the last 100 k of the ride. At the 70 k mark I found a golf course that had food, and loaded up. I waited about an hour after eating and then took off. I found that my average rolling speed increased by several km/h (I am pretty slow - my avg speed for the first 'half' was 19.8 km/h, and by the end my overall avg rolling speed was 21.9 km/h) over 15% faster!

It was a hot day for central Alberta (high was 31 C), and there was little or no traffic, and there were no facilities to speak of. For a 150 km stretch there were exactly TWO places where I could buy food/water, and I managed to find one outhouse in addition to that beside an abandoned church (came in real handy!).

For the record I drank over 5L of fluid over the day including 3L of water, 1.5 L of half strength gatorade, and 1L of orange juice (acid is a problem but much more potassium than gatorade). I ate an energy bar (250 kCal), 2 trail mix bars (150 kCal each), and a pretty solid lunch (probably about 700-1000 kCal).

Thanks for the advice Machka, I think it really helped me.

In terms of my training, I have been commuting between 15-25 km every business day since about september, with a couple of one - month breaks, and I have not ridden more than 60 km in a day for about 20 years (I am 37 now).

It seems that you really don't need to train specifically for a century if you take it slow and keep the calories and water coming.

R

P.S. the aftermath has been minimal, my quads, glutes, and arms are a bit sore, and I have been sleeping a lot in the last couple of days, but no injuries to speak of.

P.P.S. BTW my equipment is a Marin Larkspur (urban hybrid) with a fairly upright posture, and 1.25 in semislick tires. I'm sure if I had my touring bike here I could do the centrury significantly faster.

4) Don't spend a ton of time resting. The amount of time it takes for your legs to stop hurting when you restart is roughly equal to the amount of time you spend stopped.

I stop about every 10 miles after the first 15-20. But I keep my stops short and don't sit for long.

If I take too long a break I have a hard time getting going again.

About drinking-nutrition: Keep in mind your size and conditioning. I don't have a set formula other than drink alot when sweating alot. I carry a salted nut roll because chocolate melts really bad and then I have to basically suck it out of the wrapper.

Oh yeah, help the local economy and stop at convenience stores -alot. Get treats and a big gulp (diet cherry coke for me, please) and loiter a bit enjoying the air conditioning.

3. Forget about those riders who tell you that they completed a century in under five hours. Plan on a ride of ten or eleven hours. In the future you can try for a sub-five century; but for your first century, aim to complete it at a reasonable average rate of about 15 km/hr (10 mph).




10-12 hours? Does that include a 4-5 hour nap?

Cat4ever,
Not everyone can complete a century in 6 hours as you intimate.
Especially a first century.
The original intent of this thread was to encourage those who have never done a century to give it a try.
In the past, many of these riders have done a half-century; but a full century seems to be unattainable.
Many of these rider average about 13 mph (20 km/hr) riding time and they can calculate that a century would take them almost 8 hours not counting the stops.
When they hear that someone did a century in 5 or 6 hours, they suppose they have to be able to ride 17 to 20 mph with no breaks (or even faster if they stop for a bite to eat). That's quite a burden to put on someone thinking about riding a century for the first time.

While completing a century in 5 hours might be a goal for some, I personally think it is not something I would want to attain. I enjoy completing a century in nine hours including a 30 minute stop for lunch and the sand box.

The purpose of cycling, for some, is to reach a personal best. That is especially great for young people with fast-twitch muscles.
For others, the purpose is to enjoy the scenery and complete the ride.

Randonneuring rides are not races. That's the beauty of randonneuring. As such, it stands in contrast to the current sporting mentality which promotes "winners." Even in the Olympics, it is important to get the gold, silver, or bronze (the other competitors are "chopped liver," I guess). But with randonneuring, everyone who completes the ride within the time-limit is a "winner" and receives the same "prize."

Thus, the important thing is to complete a century regardless of the speed. Then, a century becomes a training ride for the primary brevet of 200 km.

10-12 hours? Does that include a 4-5 hour nap?


Not everyone wants to RACE a century. Some of us like to smell the roses along the way! :) Some of us prefer to look at the scenery rather than the road right in front of us. Some of us like to stop at interesting little restaurants or shops along the way for a bite of something good to eat rather than consuming powerbars the whole way along.

And new century riders in particular should be encouraged to just take it easy out there and not push the pace. After a person has done a few centuries then he/she can decide if he/she wants to race them, or continue to ride them casually.

Most people will need a LOT more water.

Heck I can go through a 100oz camelback in 2 hours if its a little warm out.

Another thing that most people are neglecting is that century times vary a lot based on factors other than rider skill. For example, the amount of climbing and whether or not you are drafting. When I finished a century with about 8K of climbing in 7 hours (including stops), I was pretty happy with myself. On a flat century with a good paceline going, it isn't hard to average 22 or 23 mph (probably 5 hours total time). Particularly if you are with strong cyclists who don't mind you not taking a pull very often.

I did my first century quite unprepared and survived (although, being kilometric, I didn't know I was doing one), so that would seem to confirm what you say.
Back then all I had was my old heavy 5-speed. I rode 170 km with about 1500m climbing. I carried nothing to drink and nothing to eat (being totally unaware of anything called dietetic or metabolism). I stopped once to buy a few cookies and drink a bottle of coke - I'm not sure if I had money for more than that anyway. When I got to the end, I still had a 200 m climb to do. I was so weak I didn't even have the strength to walk my bike up there. Fortunately, I could grab the shoulder of a friendly moped rider and get myself hauled back to base.
I survived because I was 15 - probably in such circumstances an adult would have ended up in the hospital.
The second century I did a few years later, with very little or no training. But that time it was less hilly, I had a somewhat better bike, and I stopped on the way for a full meal. I was barely better at the arrival, though.
Now I am 42, I ride 10000 km a year, and a century is no more an issue. But it has lost some of its magic.

I usually ride alone but today I invited a much better rider for a training ride meant to be 60 miles. Ended up a full century. 27 kmh average (not counting breaks !) Nice experience having a wiser guy to pace the trip.

do centuries really need anything other than any other short ride? i mean, a lot of the advice that's being put in i do for short rides. just asking...