Running back to back marathons
 

In the summer I'm doing a charity ride - 160 miles. It's a long way but I've done 150 before so it's not impossible even for me.

A friend compared it to a marathon which got me thinking.

When I run at 5mph for an hour I burn about 1200 calories according to my HRM. So a Marathon would take me 5 hours or 6000 calories (assuming I could keep going at 5mph).

Cycling (between 12 - 16 mph) burns about the same per hour. However cycling 160 miles is going to take at least 10 hours at 16mph so that's at least 12,000 (again, assuming I can keep going at this speed).

So, from a simple energy expended in calories point of view, this bike ride is going to be as tough as running back to back marathons. It may not be so tough on my joints, but it's going to take some energy.

Maybe I need to give this more respect than I have been. I'd be training like a crazy man if I were doing a double marathon on June!

What is certainly true is that part of your training will include learning how to eat while riding. You certainly don't want to go 150 miles on reserves.

150 miles is a serious ride. But if you train correctly, learning how to eat, you might live through it. :D

On a charity ride, they'll be rest stops with food, and liquids to replenish your bottles every 20-30 miles. Eating on the bike isn't that big a concern.

Last summer, at age 58, I rode a 175 mile 2-day charity event. 100 the first, 75 the second. I've run two marathons back in my late 20s, but not back to back.

IMO, your bike event will be easier than running just one marathon. I started day 2 of the bike event with about a two mile flat before the first climb of any consequence. I rode along that flat at about 14 mph to get the stiffness out (and did a few laps around the staging area before that). Everything was fine after that. After each marathon, I tried an "easy 5" run the next day, and suffered like you wouldn't believe. I couldn't imagine taking on another 26.2.

While 160 miles in one shot is a little bigger effort, cycling is easier than running. Less stressful on the joints. People generally don't stop at rest stops in marathons. Running downhill, you can't coast, and it actually puts more stress on your legs than running uphill. Getting off the bike for up to 5 minutes can work wonders, but you don't want to stay off too long. Use the porta jons if you have to, grab a snack (they love to hand out peanut butter sandwiches with honey on these rides), refill your bottles, and get back on your way.

You've done 150 in one shot solo? You shouldn't have a problem with the extra 10 on a group ride.

Or Ranulph Fiennes 7 marathons in 7 days on 7 continents 4 months after a heart attack... :O

Well, if you lay around the house for 3 or 4 days, you'll probably burn as many calories as running a marathon, but that doesn't mean the two activities are comparable in any way.

There's a number of factors that come in. One of the main ones is that when people talk about running a marathon, they normally have in mind that you do it at some minimum speed, but when they talk about cycling, they omit that concept. "Running" a marathon and riding a 200k are probably pretty comparable if you take 13 hours to do either one.

I'm not sure about the calorie counting. Depending on your weight I'd be very surprised if you would burn 1200 calories in 5 miles. In my fanatic runner days (60-70 miles/week) the figures are recall for a 190lb runner were on the order of 120 calories/mile.

Back-to-back marathons at a race pace would be excruciating in my experience; maybe at a very slow jog not so bad, but your joints do take a beating; might be different for a slight of build elite runner.

I've never ridden more than a Century, but I can see riding 160 miles if you can tolerate the discomfort. Around here a 160 miles ride would involve a lot of climbing which is entirely a different matter.

Remember food quality as well as quantity.
It would be hard to ride 160 miles on Cheetos and beer.

Doing the math and thinking about it from all angles is all part of the pre-event tension.

Staying in the saddle for 10 to 12 hours would be a real struggle for me. When I tour, I'm looking for a campsite after 6 hours.

Riding and running do not compare in any meaningful way at our (yours and mine) speed. I run long distances half marathons) a little below sub 12 a mile. Te same pace you posted. I ride almost any terrain (reasonable ups and downs based on 40 miles lets say) at let's say 16 mph.

i assure you beyond a shadow of a drought it's easier to ride at that pace for 6 hours than to run at that pace for 2.5 hours. Fr me anyway.

Thanks for the replies. Even ignoring my hrm and using a generic calorie calculator jogging and medium cycling are fairly equivalent in terms of calories burnt.

I know that running a marathon and riding a century don't really compare - I was in much better shape after cycling 450 miles in 4 days than I was after running a half marathon in 1 day, but it was just interesting to do the math(s) on the calories.

When I say Charity Event - what I mean is I challenged my friend to a race and we agreed to do it for charity. It's organised by us so there are no manned rest stops, but we will have a friend in a land rover providing support (and carrying food). I've read that I need to put half my hourly calorie expenditure back into my body each hour

If you're interested, you can read more about it here: www.bigmndrace.com

That's false on the calorie replacement.

i don't have the book with me as I am traveling this week, but there is a limit to the food calories you can actually process in an hour. I think it's in the 300 calories per hour range.
peating more than this simply puts distress on the system.

i suggest you go to hammer nutrition website and read the articles on endurance fueling. It doesn't matter if you eat the foods or oatmeal, the science is the same and they do a pretty good job of laying out the science of all day racing and fueling.

The point I was trying to make is that many people find they can't eat certain food while riding. It wasn't the availability of food that I was worried about.

That being said, I missed where the OP said he did 150 miles in one shot. That suggests he knows how to eat while on a long bike ride. :)

For what it's worth I reckon on about 200 calories per mile for moving on foot (walking, jogging, running, all much the same energy per mile) while I rate cycling at more like 40-50 calories per mile. Cycling at speed burns more because there's more air resistance but I'm not going to be doing that kind of speed for a long ride.

So on that basis running 26 miles (I wish!) would burn something like 5200 calories and cycling 160 miles would burn about 6400-8000.

Certainly you'll need to consider taking on some form of fuel along the way, whether that's in the form of energy bars/drinks/gels or rest stops at cafes.

Calories per mile (From various older BF threads, for example this one, reporting 35 per mile at 17 mph average.)

Riders with a power meter get an accurate report of power in kilojoules. 1000 kilojoules is pretty close to 1000 calories, since the body wastes a lot of calories as heat insteat of work.

They tend to be around 40 calories per mile. But of course, it depends on how hard they are pedaling.

One reply said to add 22 calories for 100 feet of elevation gain. (That sounds about right, since my rule of thumb is 200 feet is about the same as riding another flat mile)

Heart rate monitor calculated calories are usually way off, often double the actual number.

And I jumped to the conclusion that it was an organized charity ride with food handouts. :D

From my data you burn more calories/hr than I do. Dang it!
I burn ~800/hr at 17 mph on the bike for a "flat" century or 5.5 mph for a half marathon on my feet

Good luck on the 160 miles.

Good luck with the big ride! Look forward to a ride report when you are done!


vesteroid, thanks for the link, I really need to read up on that kind of stuff, the last big ride I did, I know I messed up on the fueling side! I hit a wall and really struggled towards the end. :(