Long tempo ≠ Elite (Great South Run)

This past weekend I ran at the Great South Run. I was not 100% happy with my performance at the half marathon, so I wanted another chance. I couldn't find a half marathon, so I figured a 10-mile race was close enough. I wrote to the "contact us" link on the Great South Run web site and asked for an elite number. Five days later or so, they wrote back and said I could have one!

Unfortunately, I didn't recover very well from my half marathon, so I was feeling pretty bad in the few days before the race. I couldn't even do two-minute pickups in my regular runs. For the race, I decided to try out my "shoulda, woulda, coulda" plan from the half marathon: I felt I had gone out too fast, and I ran the last few miles significantly slower than the first few, so in this next race I would go out slower and then pick it up.

When I checked in, I got this awesome bracelet. It would soon become clear that the other elite athletes were far more elite than I.

Lies!

I had a bit of a crisis in the morning. When I woke up, my Garmin watch was frozen at 7:29:44. No matter what button or combination of buttons I held down, I could not get the screen to say anything else. I was afraid that using it as an alarm clock (set for 7:30) had messed it up somehow. This was a significant problem, because I was depending on my watch to know how fast I was running. Big races in the U.S. often have time clocks at the mile markers, but this one didn't (probably because of the multiple-wave start). So without this watch, I would have no idea how fast I was going. Luckily, one of the elite men said "the same thing happened to my friend's watch this morning; I can fix it" and he did. Apparently, the time change (Daylight Savings Time ended) had messed up many people's Garmin watches. It turns out that if you simultaneously hold both left buttons for 15 seconds, it shuts down. Whew!

I warmed up with Sophie, a runner from near Oxford. (You may recall that I placed second in the Witney 10 and in the Oxford Half. Sophie was first in both.) We ran back and forth in the closed-off starting area, because there was a sea of humanity everywhere else. (There were 25,000 runners.) One minute out, one minute back, repeat.

All 28 elite women went to the starting line. It was cold and windy, near the ocean. There were a lot of cameras, and it was apparently on live TV ("on telly"). When Kelly Holmes fired the gun, everyone just took off. I was last by about 10 meters, and according to my watch I was still going 5:35 pace. Seriously, people, you are not all going to run 56 minutes. There was a helicopter getting the view from above. All the spectators I was running past probably thought I was in the wrong race.

Anyway, I started off in last. I soon caught up to the second-to-last woman, around the mile mark. Just before that, I passed the woman at whose house I had stayed the night before. She cheered for me very quietly, just after taking the picture below, and I waved. That was nice. Otherwise, no one in Portsmouth knew me.

About to go from last to second-to-last

The bad thing about passing that runner was that there was a huge gap ahead. We were running through the seaport, past the historic ships (the H.M.S. Victory and others) and around corners, and I couldn't tell which way the course went until I got there. I could only occasionally see some people way ahead. I was trying to keep a tempo effort at the beginning so that I wouldn't go out too hard, and my HR was about 170 for the first few miles.

The water stops at this race, and at the half marathon, gave out bottles of water. The nice thing about this is that it's easy to squirt it into your mouth, much easier than with cups. One bad thing is that it creates a lot of waste. The other bad thing is that you have to take off the cap and pull out the nozzle thingy before you can drink. At the half marathon, they handed out water bottles with the cap off, ready to drink. At this one, the caps were on. My fingers were cold, and I actually couldn't do it. I tossed the intact bottle back toward a volunteer. I tried again at the next water station and managed to take off the cap and drink. Small victories.

I was slowly reeling in the third-to-last runner, and finally caught up at the 5-mile mark, when we were back near the start/finish area. The fourth-to-last runner was not too far ahead, and I recognized her as the one who had said, on the starting line, that she was aiming for 60-62 minutes. That was apparently not going to happen (she ran 63:51). Even though so she was not that far away, it took me two miles to catch her. When I did, right around mile 7, she stayed right next to me. We ran side-by-side for a while, until I finally pulled away a bit.

A few minutes later, I was a little confused because from the way the crowds were cheering, it sounded like she must be right behind me. I was pretty sure that she would be farther back at that point. All became clear when the wheelchair competitor passed me. That was a first! We turned onto the final two-mile straight part along the ocean into a headwind, and I briefly wondered if it would be possible to draft off of a wheelchair competitor, or for him to draft off of me. However, I passed him and then didn't see him again.

The last two miles were not very much fun. It was a long, straight road with a stiff headwind and no spectators. My feet were feeling pretty beat up at this point. I was simultaneously thinking two things: "This pavement is so rough; it's really hurting my feet" and "This pavement is probably totally normal; my feet are the problem." That idea of starting off slower and picking it up totally failed, as it is not possible to make up lots of time when you are running into a headwind. Also, I didn't have anyone to chase. I could barely make out the next runners in the distance (they finished a minute ahead of me). Solo time-trialing does not lead to my best performances.

I crossed the line in 63:12, almost two minutes slower than my 10-mile splits from the Oxford and the RnR half marathons. The officials indicated for me to leave through a gap in the fence, where the rest of the women were standing and sitting. Some of them were collapsed, having run personal bests. I was fine, having essentially done a tempo run. It was anticlimactic, for sure. I watched the finish of the men's race, which was close, but not that exciting.

I went with some women who were cooling down, and made a new friend. She commented that we didn't get a race goody bag. I commented that we didn't get a medal. I asked her if she would like to try to obtain these things with me, since after all we had done the race just like the other 25,000 people. We found the place where they were handing out goody bags to the masses streaming across the finish line, and though we were separated from it by a fence, we got someone to throw us goody bags with size-small shirts over the fence. Success!

Then we wondered where they were handing out medals. Maybe 1 in 20 people was wearing a medal. That seemed really strange: usually, either everyone is wearing a medal, or no one is (if the race doesn't give out medals, or if they haven't gotten to the medal-giving-out location yet). So I asked someone where she got her medal. "It's in the bag." That's brilliant! The volunteer hands out a bag, and it contains your shirt, your medal, and a bunch of free food and promotions. Three in one!

The only thing left to do was to get pictures with famous people. I got this awesome picture with Abel Kirui in the elite tent. Oh, by the way, the elite tent was actually a temporary building, inside a medieval castle, which looked more like a fort or barracks than a castle. Pretty cool.

With Abel Kirui (silver medal in London Olympic marathon)

Then my new friend and I found out that we were allowed to eat in the VIP tent. Sweet! We had delicious shepherd's pie, couscous, hummus and copious desserts. We waited around a while and finally the women's winner, Briton Jo Pavey, came and was interviewed about her race. And we got pictures with her! I was going to leave, but then my friend said I should also get a picture with Kelly Holmes. I didn't know who she was (not being British and all) but I did get a picture, and I looked her up afterwards.

With Jo Pavey (British Olympian)

With Kelly Holmes (won gold in 800m & 1500m in Athens)

After the race, I returned to where I had spent the night and got a lovely massage from my host, who is a massage therapist. If I am ever in Portsmouth again, I will certainly get another one. If you are ever in Portsmouth, you should strongly consider getting a massage. It was awesome. Then I took the train back to Oxford. The end.

How to avoid getting cancer

Even before one of my favorite people died of cancer two days ago, I was obsessed with how to avoid cancer.

Everyone has their thing they're worried about. Some people have a family history of heart disease and heart attack, and try to eat a low-cholesterol diet. Some people have relatives with Alzheimer's disease, so they try to eat certain foods and keep active minds. Some people just don't want to get fat. In my case, almost everyone I've known that has died has died from cancer, and other people close to me have had it and survived it, so I'm somewhat obsessed with avoiding cancer.

Here are some strategies for avoiding cancer that have been clearly shown to not work.

• Eat lightly of mostly organic vegan foods, exercise every day, be skinny, enjoy your job.
  
  
• Eat lightly of hearty American foods, exercise every day, be skinny, and live in a close-knit community.

Well, I could go on, but you get the idea. I have a bone to pick with cause and effect.

Lately my strategy has been to eat foods without ingredients. Tomatoes. Apples. Nuts. Milk. I think this is a good first step, because processed foods are kind of weird. You never know exactly what's in there. (Corn derivatives, most likely.) Of course, single-ingredient foods can still be bad for you.

I think the other part of the solution is to live a happy, stress-free life in a close-knit community. I don't know how feasible that is in our society, but I think that (like running) it would add years to one's life and also life to one's years.

Anyway, this is my current question. I don't know if the answer matters.

Tang potato salad

Once upon a time, I refused to eat potato salad, because I thought mayonnaise was disgusting. About a year ago, I started making potato salad and eating it because I realized that potatoes are delicious and mayonnaise is not all that bad.

During my time in England, I have discovered a way of making extremely delicious potato salad by using sweet potatoes and vinegar. Here it is.

Ingredients:
2.5 pounds of white potatoes (about 12 small and medium)
1.5 pounds of sweet potatoes (3 or 4)
3/4 cup or 150 ml sour(ed) cream
an equal amount of mayonnaise
vinegar
6 eggs

Cube the white potatoes and boil them until soft. Meanwhile, liberally stab and then microwave the sweet potatoes about 10 minutes until thoroughly soft.

Scoop the hot orange potato part out of the sweet potatoes into a bowl. Mash them and then mix in the sour cream and mayonnaise until it is smooth and creamy.

Drain the white potatoes and then pour vinegar liberally all over them. Stir and repeat until you have poured in a lot of vinegar. I have poured in more every time I have made this recipe, and it has never been enough. If you are using 100% real British potatoes, I recommend 100% real British malt vinegar. Otherwise, you can use whatever vinegar you want.

Boil the eggs and chop them up.

Mix everything together (white potatoes with vinegar, orange mixture, eggs).

Delicious potato salad

My housemate calls this "Tang potato salad" because it turns out orange.

I think this is the most delicious potato salad because the sweet potatoes make it... sweet. I have to stop myself from eating more than is prudent in one sitting.

By the way: Because I have lots of friends who are vegan or allergic to dairy, I tried modifying this by mixing olive oil with the sweet potatoes and eliminating the sour cream and mayonnaise. Epic fail. It was not at all delicious. I am sure that it is possible to make a vegan potato salad, but that is not how to do it.

My 15 minutes of fame

Well, folks, my 15 minutes of fame has officially come to an end. I think it's time to step back and review (i.e. document for future reference) what has happened.

This pretty much sums it up 

(views of the video during my 15 minutes of fame)

Here is a rundown of all the awesome things I have been fortunate enough to experience due to my PhD video over the past few months.

June 15: I showed the video to about 60 early-career mathematicians at the AMS math research community on discrete and computational geometry in Snowbird, UT. The entire audience burst out laughing when the sentence "My theorem works!" appeared on the screen. A friendly audience indeed.

June 22: I showed the video to the undergraduates at the Summer@ICERM REU, to explain my research to them. Definitely more effective than a whiteboard explanation.

June 26: I showed the video to a group at the Exeter math conference. We tried to come up with other theorems that could be demonstrated through dance, which was difficult, but the Sentry Theorem was an obvious choice.

July 2: The GeomBlog mentions my video in a guest post by a mathematician from the Snowbird conference.
Finally a shout out for my favorite screening of the session- Diana Davis showed us her entry for "Dance your Ph.D thesis", which drew much approval from an audience worn out by the excessive number of dry beamer and powerpoint presentations we've seen.

July 2: Someone submits the video to reddit/math. It gets 118 votes and 25 comments, most of which are math-related ("what is the genus of the double pentagon surface?"). The YouTube version of the video got over 1500 views in one day.

July 5: The Aperiodical writes a post about the video.
As a mathematician (and not just any kind of mathematician – a PURE mathematician), I heard of the “Dance Your PhD“ contest and immediately burst out laughing. As much as there is some nice pure mathematical dancing out there, the idea that someone’s mathematical PhD research could be conveyed via bodily gyration was both fantastical and hilarious. However, like any good scientist, I’m happy to be proved wrong and in this lovely clip, Dance Your PhD 2012 entrant (and pure mathematician) Diana Davis explains some lovely maths [...]

July 9: Math Munch, written by a participant from the Exeter conference, mentions my video in a post about how mathematics and mathematicians take many different forms.
Let me point you to the “Dance your Ph.D.” Contest. It’s exactly what it sounds like—people sharing the ideas of their dissertations (their first big piece of original work) through dance. Entries come in from physicists, chemists, biologists, and more. Below you’ll find an entry by Diana Davis, a mathematician who completed her dissertation at Brown University this past spring. Diana often studies regular polgyons and especially ways of “dissecting” them—breaking them up into pieces in interesting ways.

August 11: The Williams College math department posts about the video on their web site (later edited to include the contest result). The Brown math department also links it from their web page.

August 23: My friend Dan Katz posts about my video on Facebook. 18 people re-share it, which is way more than when I posted it myself. He is well-connected among mathematicians and this really gets the video out there. Several hundred people watch it embedded on Facebook.
This video, created by Diana Davis, a grad student at Brown, is her entry into a "dance your thesis" competition. It is probably nothing like what the organizers are expecting, and probably much much cooler. You should watch it, and then watch the potentially even awesomer FAQ video she posted later (it should appear as a link up top when you load the first video). Great job, Diana!

August 25: howthebodyworks writes a short post about my video.
“Dance your thesis” by Diana Davis, is the first interpretive dance of group topology I’ve ever seen. Homework: do an alternative take as a slamming dancehall track.

August 30: A mathematician emails me to say he likes the video, and suggests making video games that take place on surfaces similar to the double pentagon.

August 31: PhD+epsilon links to my video in her post about "performance math":
A friend of mine recently shared with me a video of an interpretive dance of a theorem in Diana Davis’ Ph.D. thesis. As her note under the video says, this was created for submission to the “Dance your Ph.D.” competition. I haven’t seen other submissions, but I really love this one.

September 5: A mathematician emails me to ask if it is okay if he puts the video on his web page. Yes!

October 1: The contest closes. I start to get nervous.

October 4: The Brown Daily Herald wrote a front-page article about the video. Several hundred people watched my video embedded on the BDH web site.
Imagine walking in a straight line on a torus, a bagel-like geometric shape. It would be possible to go through the hole and end up where you started, walk around the perimeter and end up back at the beginning, or to walk in spirals and zig-zags. These are the surfaces that serve as the subject of thesis research for Diana Davis GS, who is studying in the Department of Mathematics.

October 5: A shortened version of the BDH article appears in Russian.
Представьте, что идете прямо по валику, по форме напоминающему бублик. Можно пройти через дырку «бублика «и прийти, откуда начали путь, пройти по периметру и оказаться в начале, или же идти по спирали или зигзагами. Такие «бубликовые» поверхности служат предметом диссертационной работы для Дианы Дэвис с кафедры математики университета Браун на Род Айленде.

October 5: Brown Graduate School posts about the video on their Facebook page.

October 9: The 12 finalists are announced (3 in each category). "Cutting sequences" is among them. Whew! Several hundred people watch the video.

October 12: I was secretly notified that I had won the Physics category and had not won the entire contest. The contest organizer and I went back and forth with many emails. He told me that I should definitely go to TEDx Brussels since Oxford is so close to Brussels, and he got me a free ticket (TED, not plane).

October 14: The winners are revealed to the world. 1,000 people per day (!) watch the video.

October 14: I do a phone interview for BioTechniques.

October 14: hyperbolic crochet writes a long post about Veech surfaces, including pictures of models she made to better understand the double pentagon.
By now it is 3 am, and I am still thinking of Veech surface. That dance gives a very nice illustration how this surface can be otained by identifying sides but I cannot visualize. I am trying to get back to sleep but I am still puzzled with what I read in Hubert's and Schmidt's paper: " An easy Euler characteristics calculation shows that it has a genus two. As a genus two surface it has a hyperbolic covering."

October 15: BioTechniques publishes an article based on the previous day's interview.
To create her winning submission, Davis screened multiple versions of her video to family and friends without backgrounds in mathematics to ensure that her research was being explained in a clear manner. “With earlier versions that I thought really explained my theory [well], other people would say, ‘What is going on?’” said Davis. “I was sort of discouraged. It went through a lot of iterations.”

October 15: I email a mathematician to ask about a postdoc job for next year, and he already knows about me because a colleague shared the video with him.

October 16: W.A. Veech, the mathematician who discovered Veech surfaces, sends me an email. (!!!)

October 17: Brown University posts about my winning the contest on their Facebook page. Almost 100 people like it and 51 re-share it.

October 17: I do an interview via Skype for the Physics Buzz podcast. It hasn't come out yet. I just hope I don't sound like a jabbering idiot.

October 18: Marlborough School posts about the video on their Facebook because Libby Stein, the wonderful dancer, went to high school there. She told the school about the dance and the video:
"Last fall, I took a multivariable calc class taught by a Ph.D student here at Brown ... She told me about a contest called 'Dance Your Ph.D.' where any graduate student can submit a dance explaining their Ph.D. She asked me if I would help her compete and of course I agreed ... I just wanted to let you all know about this because my love of math really started at Marlborough. I would not have even considered taking a college math course if not for the amazing experience I had with Marlborough's faculty and staff."

October 19: A mathematician emails me to ask if he can use clips and stills from the video in a colloquium talk. Yes!

October 21: Brown University features the video on the home page just above the Dalai Lama, and writes a press release about the video.

In conclusion: The video has been watched about 10,000 times, which is probably 1,000 times as many  people as read the math paper where I proved the result. This video has spread the word about my research far further than I ever could simply by proving theorems and writing papers, or even by giving math talks. All of the mathematicians I have heard from seem to love the video, which makes all the hard work we put into it pay off. It has been a wonderful experience.

Thanks again to Libby and the rest of the dancers for making this possible.

---

Update: Brown linked to the news article about the video in the Brown Insider, an email sent to all alumni. Over 1,000 people watched the video as a result.

Spike in views due to Brown's email

How to run a 51-second PR and still feel like a loser

I almost never write blog posts about races that went poorly. If you read through this blog, you probably get the sense that my racing career consists mostly of winning small races and setting PRs, and I never have a bad race. That's because it's really hard for me to sit down and spend time writing about things I did poorly. Well, here goes.

In reality, the Oxford Half Marathon didn't go that poorly. As mentioned in the title of the post, I ran a 51-second PR. I improved my time to 1:21:10, which is certainly no jog in the park.

However, I spent more than three months training for the race, so I didn't just expect it to go well. I expected it to go really well. I wanted to run under 80 minutes. I wanted to win the race.

Neither of these things happened. One reason I didn't achieve my goals is that I ran the first mile too fast, which is a rookie mistake. To have done three months of hard training and have it compromised by poor decisions over the course of just five minutes is tough to swallow.

Anyway, the race.

Conditions at the start were perfect: sunny and 40°. Conditions in the several hours before the race were decidedly arctic. I could see my breath. There was frozen mist floating through the air. I had not prepared for this, so I shivered for a while.

In this news video you can see me twice, standing on the starting line.

Roger Bannister sounded the air horn and I ran what I felt was a reasonably quick, yet not difficult pace. Many men passed me, but no women. The first mile was gradually uphill, and it didn't feel too bad. Just before the mile mark, Sophie caught up and passed me. I got to the mile marker in 5:44.

I am in the middle, in a green singlet and sunglasses

I assumed that the mile mark was wrong and decided not to worry about it. I got behind Sophie and ran just behind her for the next few miles. She was going about the pace I wanted to go, so I just tucked right in and let her set the pace. We went through the next few miles in 11:54 (6:10), 17:57 (6:03), 24:01 (6:04). My goal pace was 6:06, so this seemed pretty good to me.

This is how it was from mile 1-4

Between mile 4 and 5, a gap opened between Sophie and me. I wasn't sure if she was speeding up or I was slowing down, but I felt I was exerting the right amount of effort.

I missed the 5-mile mark, which I am mad about because I really wanted to know how fast I was going. One thing I didn't like about this race was that the mile signs were attached to fences or posts well off the road, so you really had to be looking for them to see them. I didn't see mile 5.

The sixth mile was a gradual uphill. Even though I didn't feel like it, I got my Gu Chomps out and ate three of them (I dropped the fourth on the ground accidentally).

I got to the 6-mile mark in 36:43. What?! Did I really average 6:20 miles for the past two miles? That would be horrible. I had decided not to start "racing" until mile 8 or 10, but I was determined not to get stuck in a 6:20-pace rut, so I injected some purpose into my running for the next mile.

I got to the 7-mile sign in 42:10, meaning that I was averaging 6:01 pace since the beginning of the race. You have got to be kidding me. Either the 6-mile sign had been late, or I ran a 5:27 mile (not likely). I was pretty sure the 7-mile mark was in the right place, so the good news was that I was apparently running a fast half marathon, and the fact that Sophie was well ahead of me was not my problem.

At this point I was really, really wishing I had just worn the darn Garmin. I didn't wear it because during my previous 10-mile race it beeped well before each mile mark, and beeped earlier and earlier as the race went on, so I didn't want to deal with the discrepancy between an actual mile and a "Garmin mile." However, an "Oxford Half Marathon mile" apparently has a huge standard deviation and sometimes does not exist at all. Not cool.

Running along the towpath

Miles 8-10 were my favorite part, around the towpath along the river. I was running alongside this guy, and I would alternately pass him and he would pass me, based on who was feeling good. I missed mile markers 8 and 9, but I knew where 9 should be, and I got there in 54:57. At this point I didn't know what to believe, but I can believe I had slowed to 6:20 pace (which, it should be noted, is still not that slow).

I was hoping I would get to 10 miles in a good time, because I knew the 11th mile would be difficult: it had a switchback, which always slowed me down when I practiced it, and most of that mile was a long, gradual uphill. I got there in 61:20 for a paltry 4-second PR over my RnR split from August.

Running along the scenic towpath

At this point, Sophie had disappeared into the distance. I could still see her until about 7 miles, but now she was gone. Fortunately, there was still room for me to achieve my goal of a PR, because I had purposely run slowly in the last 5k of the RnR half. The half marathon is basically 10 miles plus a 5k, so if I ran 20 minutes for the final 5k, I would run 1:21:20 for the race and beat my 1:22 PR. I basically did exactly that.

The last few miles were not very much fun. I ran around the switchback, up the long hill (6:40 for that mile) and then through the roundabouts in the last few miles of the race. I was mad at myself for running too fast in the first few miles, because that mistake was clearly affecting me now. Finally we approached the stadium.

Seeing 1:21:06 on the clock; finally finishing the race

I was happy to see 1:21 still on the clock as I approached. That's not that bad. I crossed the line and it was over.

Just after I finished, I met up with someone I knew from a local running group. He was happy I had finished second lady. On the starting line, he said he wanted to run 1:25; he had run 1:19. I wish I had exceeded my goal by six minutes!

As I walked out of the stadium, several people congratulated me for being the first lady. I temporarily entertained the notion that Sophie might have dropped out, but it seemed unlikely (she didn't).

I got my race T-shirt from the volunteers. As I have mentioned, in the UK, T-shirts are for finishers, not entrants. The nice thing about this is that the faster you run, the more likely you are to get the size you desire. I got a small. They were all men's cut, though. Apparently women's-cut race shirts do not exist in the UK yet.

Then there was a crowd of people standing around these machines. You type in your race number, and it tells you your time and place!

The cool device to see your race time

And if you touch your name on the screen, it prints out a receipt with this information. Very cool. This is a great benefit of chip timing, and it eliminates the huge crowds of people around the results taped to the wall. This is mostly because there are no results taped to the wall. We should do this in the U.S.

Well, actually the big crowds in the U.S. around the results on the wall are replaced by big crowds in the U.K. around the magic machine. But at least it's instantly available! No waiting for the timer man to get a full page of results, print them out, and tape them up! And you can take it home! More dead trees for everyone!

I ran 1:21:10 and I have a receipt to prove it

Then I was thrilled to see that Sir Roger Bannister was still around! I thought he might have gone home after finishing his duties starting the race, but no, he and his wife were still there. I ran to the baggage claim, got my bag, fished my camera out, and went back to where he had been. He hadn't gone far; luckily for me, he is a little slower now than in 1954. He said he was looking for the women's winner, but since he couldn't find her, he was happy to talk to me. He asked me a series of questions that seemed prepared -- what was your time? are you happy with it? what do you do? what are you doing in Oxford? how many miles a week do you run? -- which seems to me a brilliant method for dealing with frequently talking to people who want to meet him. And he let me take a picture with him!

With Sir Roger Bannister!

Then I cooled down a bit and went to the awards. I was surprised to learn how close behind me 3rd and 4th places were. If I hadn't run a PR, I would have been 4th. The 3rd lady could almost certainly see me for much of the race.

The long and short of it

The prize was the most money I've ever won in a race: £200 (about $323)! Unfortunately, it was in the form of a gift certificate to a local running store, to buy Brooks products. Well, I'm sure I'll find some good things to buy there, and I'll just tuck them in the closet to wear far in the future when I am no longer a New Balance athlete. I also got a very comfy Brooks sweatshirt. Don't worry; I only wear it indoors where no one can see me.

I briefly entertained the notion of finding another half marathon in two or three weeks, and then wearing the Garmin and sticking religiously to 6:10 pace for the first 8 miles. However, I've decided to move on. It's cross country season. I'm going to break out the spikes and see what happens on the muddy fields. See you out there.

---

Update: I did find myself a 10-mile race (the Great South Run), and stuck to 6:10 pace for the first few miles. The result was a 63:12 10-mile, almost two minutes slower than my 10-mile split from this half marathon. I started at 6:10 pace and slowed down from there. So in retrospect, I am pretty happy about my performance at the Oxford half marathon, and I'm not that mad about my 5:44 first mile. If you're going to slow down, you might as well slow down from a faster pace than from a slower pace.

Exact change

Everyone likes exact change. If you're buying something that costs $2.57, for instance, it's nice to give the cashier $3.07, instead of a $10 bill.

That makes sense. However, British bus drivers take this logic way too far.

Crazy change experience #1: Taking less than the price, rather than making change.

Shortly after I arrived in England, I decided to do a race about 15 miles away. Happily, the city bus had a route that would take me within a mile of the start. Great! I tried to look up the fare online, but to no avail. All I could determine was that the maximum possible return fare was £4.80. So, just to be safe, I brought all the change I had (£3.80) and £50 in bills besides. I had learned that England is really expensive, and I was not about to take the chance that I would a 10-mile race and then have to run 15 miles home due to running out of money.

I got on the bus and told the driver where I wanted to go. "That'll be £3.90," he said. I handed him a £10 bill. 

"Don't you have any change?" he asked. I poured all of my change into my hand and held it out to him.  He quickly counted it up. "That's only £3.80," he said, "not enough."

"Right. That's why I gave you the £10." I held it out again. "Don't you have any other change?" he asked. "No. This is all I have." (What, would I hide coins because of some secret agenda?) He sighed and took the £10 bill. Then he changed his mind, handed it back, and took the £3.80 in coins instead.

Crazy change experience #2: Taking all my money and not giving me change.

I was going to meet my parents in London for the day, so I got £20 from the ATM. The return bus ticket cost £13, and I figured that the remaining £7 would be enough for my expenses during the day in London.

I got on the bus at the head of a line of people and handed the bus driver my £20. "Do you have £3, so I can give you a £10?" he asked. "No, sorry, this is all I have." "You don't have any other change?" I poured all the change out of my wallet into my hand and held it out. "You don't have any pound coins?" "No, sorry." 

He sighed, took my £20, and handed me two receipts, then started to move on to the next person.

"Excuse me, I need £7 change," I reminded him. He took one of the receipts back and showed it to me. "Give this to the bus driver tonight, and he'll give you the £7," he said.

I looked at the receipt. It was essentially an IOU from the Oxford Tube to me, for £7 (about $11). 

Really? Is this even legal? They just take my money, and then instead of giving me change, they give me this slip of paper. Awesome. So if I lose it, then they never have to give me my change. Also, I now had no money for my day in London. (Of course, I could still use a credit card -- which is not as simple as it seems, and provides enough material for its own post.)

That evening, I got on the bus, showed the driver my ticket, and then gave him the IOU for £7. 

"Do you have £3?" he asked. 

"No! If I had £3, I would have given it to the driver this morning!" I was getting a little fed up with this racket.

"But you must have spent some money in London today, and gotten change," he said.

"No. The bus driver took all my money this morning, and just gave me this piece of paper."

He literally argued with me for another 30 seconds, expressing disbelief that I didn't have change, and refusing to give me my money. Finally, he gave me £7 -- a £5 bill and a £2 coin. Was that so difficult?

Let me help you with that

In the past week or so, it has happened twice that people have asked me math-related questions for which I felt unqualified. Both times, it ended up being awesome. Here goes.

---

My housemate: "Hi, Diana. I really need your help. I can't understand the T-statistic that Excel is outputting for my data analysis."

Me: I don't even remember what a T-statistic is. I guess I can look it up online. "Sure, I can take a look at it."

Housemate: "I spent six hours today looking it up online and I still have no idea."

Me: Oh, no. "Okay, show me."

Housemate: "See, it says here 2.58E-10. What could that possibly mean?"

... so we had a little discussion about scientific notation, and he was good to go.

---

Dinner guest: "So, you basically do knot theory, right?"

Me: Um, no. "Well, I do geometry, and I study surfaces, which is kind of similar."

Guest: "I have a knot theory question for you. You might not know the answer, but I've been wondering this for a long time."

Me: This is highly unexpected. "Okay."

Guest: "Can you explain, in layman's terms, what an unknot is?"

... yes, that I can do. (It's a circle.)

---

That's all for this time! Diana's wealth of high-level mathematical knowledge, improving the world one question at a time!

How to run faster

There are two ways to run faster. They are very simple.

1. Increase your stride rate, so you are taking more steps per minute.

 2. Increase your stride length, so you go farther with each step.

Your speed is (stride rate) x (stride length). Very simple.

Some months ago, Alan noticed that I have a very high stride rate, or cadence. The rule of thumb is that you should take 180 steps per minute, or 90 with each foot. Most people take fewer than this, and try to increase their stride rate up to this apparently ideal 90. Alan noticed that my cadence was approaching 100 when I was doing strides. That's pretty high.

Now that I have a super-fancy GPS watch with the associated accelerometer foot pod, I can collect data on this stuff. (Thanks, Gary at Garmin! Thanks, Rhode Runner!) As you can see from the graph below, I usually have a cadence of 95-96, and the faster I run, the higher it goes, up to 104.

This graph just shows averages for entire miles. I actually have a cadence over 110 when I am doing strides (sprints) sometimes.

A high cadence is not necessarily bad. However, it could be bad, if I were taking lots of tiny steps when I run fast. In particular, it would be bad if I were increasing my stride rate without increasing my stride length.

Luckily, I can figure out my stride length from the copious GPS data as well.

Did you think the first graph had pretty good data? Did you think it was pretty linear? You hadn't seen nuthin' yet. This is some of the most linear data I have seen. And it came from real life!

From this graph, we can see that as I run faster, I also increase my stride length, from a normal length of about 3.5 feet to well over 4 feet when I am going fast. By the way, that means my footprints would be 3.5-4 feet apart (it's not measuring right foot to right foot).

So, I don't need to worry: I'm increasing both stride rate and stride length as I run faster. That's exactly the way it should be. As for the high cadence, it's much better than low cadence, and it puts me in good company with many elites who have cadence near 100.

Pretty cool.



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Every day is an adventure

"Every day is an adventure" -- I've been saying that a lot recently, because I'm living in a different country, and every day I'm going places I've never been, often places that I've only seen on the satellite view on the computer.

Left: Oxford Half Marathon course (one of two sides).        Right: OUCH Handicap Run course

When I go exploring in a new place for the first time, I bring a map. Usually it looks like one of the maps above.

"You might get lost," someone said to me. "Don't worry; I have a map," I said. "Let me see the map," the person said. I handed it over. "I don't think this map will do you much good," I said.

These maps make perfect sense to me. They are completely topological; one inch equals 100 feet in one places and two miles in another place (which is why I often put in mile markers). They are covered in road names. A squiggly line means a river crossing. A shaded area means a hidden footpath through trees. A circle with lots of lines coming off of it means yet another (!!!) roundabout.

I have a ton of these little maps on scraps of paper, because of my project running all the roads in Deer Isle. I decided I liked them, so I kept them in a pint glass. Maybe someday I will make them into something. Some people cover a wall with paint or wallpaper, others with race bib numbers; I may cover them in crumpled scrawled maps.

The aftermath of 8 laps around Christ Church Meadow

"Oh my god! You're covered in mud! What happened?"

(it was true)

"Well, I ran through a puddle, and then I ran through it again, and then I ran through it again and again and again."

"Sounds like a psychological issue to me."

The plan was repeats of some distance like 2k or 1.5 miles, so I chose to run around the perimeter of Christ Church Meadow (1.33 miles, as it turned out). I like running around Christ Church Meadow because it's a dirt path, it's a beautiful place to run, and there aren't too many people (especially when it's raining). I put off my interval workout until the afternoon, conveniently after a few short rain showers had turned the dirt path into a long ribbon of yellow puddles.

Puddles don't really bother me. I noticed that my feet occasionally got wet, but it did not occur to me to check my legs and back for mud. As it turned out, I was covered in yellow mud, which turned into caked-on dried yellow mud. It must have some special properties, because it stuck on pretty well. When I took a shower after the run, the washed-off mud in the bottom of the shower was approximately 3 inches deep. (I actually got stuck in it and I am writing this post from the shower.)

Let me tell you a funny story about Christ Church Meadow. I ran in it one of the first days I was in Oxford, and found it to be a lovely shady park. I ran along the river, beneath a canopy of trees the whole way. I thought it was a great park full of trees.

Then I looked at the satellite image later, and discovered that the park actually has barely any trees:

The blue marker is the garden where Lewis Carroll told fanciful stories to young Alice.

As it turns out, Christ Church Meadow is a meadow. They graze longhorn cattle in the middle of it. English longhorn cattle, not Texas longhorn cattle, if you were wondering.

There is another lovely park in Oxford, whose perimeter is coincidentally exactly the same 1.33 miles. The experience of running there is also of a tree-filled park. In fact, it also has barely any trees. It boasts a cricket pitch and multiple rugby fields. However, all the paths are lined with trees. Very misleading.

The park is called "University Parks." When people refer to it, they use the plural. "Let's meet at Parks." "I did some lovely loops around Parks." "Parks is good if you want to run on the dirt."

No dodo birds were created or destroyed in this Parks

See you all later. I'm going to go run around a Parks.