milkbaby

I'm a marathoner who likes to cycle for fun. I've run 13 marathons but only ridden one century. IMO, the marathon can physically beat your body up worse than a century. Due to having my saddle too low (it's now at least 4 cm higher, DOH!), one of my knees was blown up just 20 miles into the century, but I still was able to finish the last 80 miles. Not sure I would've been able to continue running if I was just 1/5th of the way into a marathon with the same knee pain. The weight bearing impact nature of running induces more eccentric muscle damage and eventually your body may shut you down. Of course, when you hit your limit riding, the same can occur but I think you get more chance to recouperate during the ride by soft pedalling and coasting. Most people also have less difficulty taking in nutrition while cycling versus running.

You'll have an easier time with whichever event you trained best for. My marathon times the last 3 years have all been about 3:12 +/- a minute but it took me a disappointing 6 hours to ride 100 miles (blowed up knee and all). However, that was after only doing "training rides" of 39, 67, and 83 miles to "prepare" for a century which I did 6 weeks after getting a bike -- obviously not optimal preparation... On the other hand, it could be argued that all my running was prior crosstraining for the century. Now I've ridden more, I think I could get in under 5 hours without much stress riding with a group (as long as it's not all uphill into the wind!). I may be biased being a runner who crossed over into doing a little cycling, but I think that is the easier path rather than a cyclist getting into running. However, I'm sure anybody who can prepare and train properly without getting hurt can successfully enjoy either event.

One interesting experiment to try: One day ride 100 miles then run 26.2 miles. After recouperating enough days, the next time try running 26.2 miles then riding 100 miles.

bobthib

IMHO - Century = Piece of cake. Did my first at 61, after 9 months of riding. 19 mph ave ride spd. Have done 2 more and numerous metrics. Did one Century at over 20 and could have gone 40 mi more easy (it was an organized charity ride and we had a police escort. Only stopped 3 times at rest stops)

Marathon = hell. I'm not sure I could run much more than a mile. I have neuropathy in my feet, and they hurt 24/7. I can't imagine beating them up for 4 o 5 hrs.

unterhausen

I think the **** measuring contest is going on in foo

daveF

[One interesting experiment to try: One day ride 100 miles then run 26.2 miles. After recouperating enough days, the next time try running 26.2 miles then riding 100 miles.[/QUOTE]

It's not as difficult as it sounds. A lot easier than an ironman. I've done several 50k's then gone to work. Then, the next day or two done 90 to 135 mile rides. I could do that relatively easy, but couldn't figure out how to put together a good nutrition plan for an ironman. I think I've figured it out now while training for a 100 mile mountain bike race.

milkbaby

My question isn't whether it's doable -- like you said the distance is further in an ironman tri -- but whether switching which event is done first and which second makes the entire distance more difficult. Whether 1) running the marathon first then biking the century is harder or 2) whether biking the century then running the marathon is harder (and I'm not talking on separate days, but one immediately after the other). The reason IM triathlon is set up swim/bike/run is so when you're exhausted at the end you just start walking or flop over on the side of the road instead of crashing your bike or drowning in the water (also easier to lifeguard a mass swim start rather than impossibly spread out over multiple hours).

daveF

It's easier to run 1st day, then cycle the next rather than the other way around in my experience. Easier to cycle 100 miles when your legs are beat up rather than run.

superdex

something like this? https://bicyclerace.com --

Finish Elevation 14,130’
(4,307 meters)
27.4 miles from start
Net vertical gain
6,575’ (2,004 meters)
6,915 climbing feet
Course Records
Men – 1:41:20
Tom Danielson, 2004
Women – 1:59:19
Jeannie Longo, 1998

FrenchFit 

I've done centuries with no more pre-thought than filling a couple water bottles and grabbing some cliff bars. It just isn't a big deal. However, if you are focusing on quick times or repeated / contant hill climbing, then it probably is a big deal. Still, biking v. running, I can't see any comparison. Running long distances requires serious training and lots of physical and mental issues that have to be right - or epic fail.

Bacciagalupe

Having done several centuries and not much running I feel very comfortable saying that a century is much easier than a marathon. I'd say that with about the same level of training for both sports, a half marathon on a hot day is a little bit harder than a century on a cold day.

Even if you're trying to do a sub-5-hour century, the bottom line is that cycling is low-impact and running is high-impact. No amount of training will even these two aspects out.

Or, think of it this way. Let's say I spend 3 hours on the bicycle, riding in the aerobic zone (70-80% of max HR), and the next day do a 3 hour run in the same HR zone. The run will still beat you up far more than the bike ride.

unterhausen

I really don't think that an easy marathon is that big of a deal for a properly trained runner. If a runner's mechanics aren't good then no distance is easy. A good runner doesn't exactly beat themselves up on a run of any distance, the people who don't know what they are doing might.

Boudicca

Girly???

Come on? Can't you find a better adjective than that?

I will cycle rather than run any day. Sure the hills are harder, but you get to rest on the downhills. You can have microrests on the flats for that matter. Even the downhills are work when you run.