Wednesday, December 29

Short Bike Commutes Can Be Costly

Andy Cline, at Carbon Trace, has a short bike commute. He knew where he was going to be working for many years to come and picked a house nearby. I confess that, despite a slight bittersweet taste when ending a memorable commute, I was quite pleased to trade my 20 mile v2 commute for my 7 mile v3 commute. However, I have discovered that there really IS no such thing as a free lunch and that a shorter commute does carry some cost. You might wonder, HOW is anyone worse off in any respect whatsoever by suddenly living closer to work without even having to have moved? Andy Cline might wonder, “Have I missed something?” Well, yes.

I have now made my new v3 commute long enough to project my weekly commute mileage. Conveniently, I also tracked my weekly mileage on both the v1 and v2 commutes. I find it interesting to note that the results do NOT show I double my bike mileage if I double my commute length, but the bike mileage does increase. In the case of a bike, decreased bike commute mileage means decreased calorie burn. Decreased calorie burn means either one must cut down food consumption or make special trips to go work out to maintain equilibrium. Acch. Diet and exercise!

That is bad enough, but it transpires that I can be more specific than that. Since I’ve kept commute logs, I can quantify things and determine precisely the penalty I shall have to pay for my new, short and easy commute.


Published Calorie Expenditure Chart
 To start off, if you look at the published table, riding a bike will cost somewhere between 40 and 50 calories a mile for the vast majority of us. While wind resistance plays a role, going slower doesn’t help much with basic rolling along, and few of us are going to be riding to work at an average speed over 20mph. For purposes of the analysis, energy expenditure on a bike commute is about 45 calories per mile and I use that for the calculations below.

The NEXT table shows how my own, historical daily average mileage related to different commutes. Remember in this table that daily average mileage uses seven days per week while the commute takes place in five (if you work seven days a week, we need to talk). In addition, you don’t commute when sick, on holidays, or vacation. Finally, remember that working at a more remote location means there will be more days in which driving is needed, simply to make it to appointments or other things where the bike simply isn’t fast enough to make it between two distant points in the needed time. The really short commute assumes that I’d be able to ride even a bit more frequently than my new, 7 mile commute. Even if you work at home, there will occasionally be appointments and such that simply mandate a motor vehicle, whether it is an owned car, a taxi, or a rented car.

Bike Commute Cost Comparisons
The table sorts things into increasingly long commutes. As you can see, based on historical numbers, commutes start to require significant payments as they get shorter, and the penalties in weight gain for not making those payments get more severe as well. Of course, there are many ways to vary the payments; for example, I personally could avoid the 17 pound gain by omitting 2 cheese sticks per day. Looking at the table, I thank my lucky stars that I work in an engineering job rather than the barista or Walmart greeter jobs that might fall within the theoretical “very short” commute. I’d be stuck going to the gym twice a day every day or undergoing serious food deprivation. How DO those motorists (and Andy) stay slim and trim? Perhaps they dollarize their time savings and spend it on bariatric surgery and Jenny Craig…

The Cost of a Short Commute - Extra Workouts, Dietary Rationing, or Weight Gain!

7 comments:

Oldfool said...

I believe that one does not eat to live but for entertainment. My average daily consumption is between 1800 and 1900 calories a day and that includes 500 to 700 calories of red wine. So you see I'm not eating much solid food. Most of those calories are in the form of grease to make the fiber slide down easier. I know this because I keep a daily food log.
My only activity is biking, cutting firewood,working in the garden/shop and fidgeting. I think I need to increase my fidget level. I never worry about starving to death. I can lick the inside of a potato chip bag and live but only one, two will make me fatter.

Apertome said...

I enjoyed this analysis. Funny stuff!

Chandra said...

Very nice post with data! My GPS shows that I burn roughly 490 calories per a 10.01 miles ride, on the average and I know my bike is heavier than yours and I probably am heavier than you as well.

Anyways, I am curious if you were to load up your bike (somehow), that will not benefit in two ways: 1) more calories will be burned and 2) possibly that might help you future self-supported bicycle tour?

Peace :)

Justine Valinotti said...

I'm glad you provided this data. And your discussion is interesting.

I also think of another trade-off one makes for a shorter commute. It's psychological: When I had longer commutes, I could really unwind at the end of a day.

Big Oak said...

You know, if you gain more weight, you'll burn more calories per hour. Or if you commute at racing pace (>20 mph), you'll burn a ton more calories.

John Romeo Alpha said...

This post is well done with data and analysis. It is on target for someone who monitors their activity and calories daily, and is health-conscious, and understands the calorie input/body weight/activity balance. With that understanding, you already know that if you ride less, you need to cut back on something. Maybe the cheese stix.

RANTWICK said...

This resonates with me, man. My commute of roughly 4.5 miles one way simply isn't enough to keep weight gain at bay. This is a bad thing since my diet sucks and riding is pretty much my only exercise. In summer I stretch (about double, usually) my commute and that hepls, but in Winter I generally don't. I am heavier than I have ever been at this precise moment. Happy new Year's resolutions!

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