The answer to that question may seem obvious if you look at it from a time standpoint: it's much exerting and tiring to run for ten minutes than to walk for ten minutes. However, if you think of it from a distance perspective, the question is harder than you think. You could walk five miles in ninety minutes, or run five miles in thirty minutes. Sure it's more tiring running, but you're exercising for three times longer if you walk. Now it doesn't seem like a straight forward question does it?

Jumping to the conclusion: You burn more calories running the same distance than walking, but the speed at which you run doesn't matter as much unless you run very fast.

Here is the plot comparing calories consumed walking and running at different speed (click to enlarge):

191 pounds is the average male weight ages 20-74 years, and 164 pounds is the average female weight ages 20-74 years in the US (source). The calorie consumption per minute for each of the running and walker speeds were taken off the Healthstatus.com website (I entered 100 minutes for each activity then divided to get the extra significant digits).

As you can see, you spend more calories running the same distance than walking, but there is no clean correlation between speed and calories spent. In fact, you spend less calories if you walk briskly or too slowly than if you walk at a normal speed. On the other hand, you spend more calories running slowly or running very fast.

The above comparison falls short, however, since each exercise takes different lengths of time. Since the human body consumes calories while resting (or even sleeping), in the above comparison the runners are not given the benefit of finishing early and burning calories after the exercise.

For the following graph, I set the total time to be 150 minutes (how long it takes to walk five miles at 2 mph) and added the resting caloric consumption for exercises that don't take as long (I chose "reading" off the Healthstatus website since resting wasn't available).


As you can see the benefits of running is now further exemplified by adding the extra resting calorie consumption. Nevertheless, there still isn't much benefit in running fast, unless you run very fast. Of course this completely ignores the benefits of extra time which enables you to do things like lifts weights or blog.

In conclusion, lessons learned from this number crunching exercise:

1. Run if you can, you burn more calories than walking the same distance.
2. Don't worry about running fast, unless you run very fast or you want the extra time for something else.
3. Fast walking is counter-intuitively unproductive. Try to step it up to a light jog.

If you want to play around with this more or just want to double check my numbers, here is the Excel spreadsheet I used to create these charts.

Labels: exercise, health, random calculations

My coworkers and I just ran a back-of-the-envelope calculation on the societal cost of all these people waiting for the iPhone:

150 Apple Stores in the US. Approximate, but close. If someone wants to count: Store list.

100 people per Apple Store. While the NY and SF stores are getting all the attention, the Apple Store in Palo Alto has more than 150 people waiting. I actually think this number is conservative.

10,000 AT&T stores in the US (Source). I’m not sure how accurate this figure is (and if it includes authorized resellers who aren’t going to be selling any on the first day), but we’ll go with it for now.

20 people per AT&T store. It seems like the AT&T stores aren’t getting the same love as Apple stores, but 20 feels like a conservative estimate.

8 hours waiting per person. While the “iLoser” decided to sit in line 100 hours before the release, I think most people started first thing in the morning today.

$20/hr per person. This may seem high, but the average salary in the US was $15.54/hr in 2004, and you have to have some financial clout to afford a phone that’s going to cost you $2000+ in the next two years. I’m sure the mayor of Philadelphia makes more than that too.

What does it all add up to?

(150 Apple Stores x 100 People/Apple Store + 10,000 AT&T Stores x 20 People/AT&T Store) x 8 hr/person x $20/hr = $34,400,000

So there you have it. $34.4 million in people’s waiting time for the iPhone. To be fair though, it seems like some people were actually working while waiting in line with their EVDO cards and laptops (and others were waiting as their jobs).

Nevertheless, we need to come up with a new paradigm for buying release day products so that we don’t waste so much time. Any ideas?

PS Sorry for the long hietus. I should have some extra time in the coming weeks and have some ideas lined up to blog about.

Labels: iPhone, random calculations

You ever wonder what would happen if you could record everything you heard and said in your life? Put it into one large text file so you could search through and remember how you rejected on your first date?

So how much do you say and hear in your life? Okay, so this is the shadiest number in the equation, but how many words do you think you hear and say in a day? Not a foggiest idea? Me too.

So, here is a bench mark. Shakespear's Hamlet is about 27,000 words, and it's about 3 hours long. Now that includes scene directions and character headers, so you can take it down a notch to, say 24,000 words. In other words, an hour of full blown conversation is about 8000 words, or 133 words a minute.

Now there is no way you spend 16 hours of your waking time engaging in, or listening to full blown conversation. Not even 8 hours. But let's slightly over estimate and say you hear 3000 words an hour on average and 3000x16 = 48,000 words a day.

48,000 words a day, 17,520,000 words in a year, 1,401,600,000 words in your 80 year life time.

A word is about 4 letters long on average, and you need a space to separate the words, so assume you need 5 characters per word. So in your life time, everything you say and hear can be stored in 7,008,000,000 characters.

A character is a byte, so you're looking at 7 Gb for everything you say and hear in your lifetime. And that's not taking into account any compression you apply on it, which could drop it easily down to less than a Gb.

So it quite doesn't fit into any of the USB memory sticks shown above, but there are ones out there larger than 8 Gb. Really, your life fits into a collection of plastic, silicon, and copper the size of a quarter.

So what does this mean? I don't know. But really makes you wonder sometimes.

Labels: random calculations