Day: April 29, 2005

Polar HRM

What's this?

The Polar S7xx family of bike computers has a handy feature that allows you to download your exercise data to a PC running Windows. Thanks to the work of Dave Bailey, the Polar family now runs on Linux, too. Dave provided software to read Polar data into the PC and to display it in graphs. Later, he added a Perl interface to the library that makes his work accessible from scripts.


I am not really the greatest Perl programmer in the world, but there were a few things I didn't like about Dave's graphs: they are fixed size, which means a short ride gets the same width as a really long one, and that the altitude changes are not reflected in the graphs. This means that a ride with an elevation gain of 100 feet may look on a graph just as steep as one across the Sierras.

So far so good. Turns out, though, that the Perl script to create the graphs that I wanted was really short. Even after I added a few twists (like stitching workouts together for those pesky days when the monitor decides that your 'short' rest warrants a new workout), it ran just above 4k. How's that for efficiency? (more…)

Reading Windows HRM Files

Some of us have started working out on the Polar series before Dave had completed his software. Then we are stuck with two different file formats that are entirely incompatible, since the Windows software saves a stripped down amount of information into files with the extension .hrm after download.

The HRM file structure is fairly well documented in a related project, called Polar Viewer. The author, Stefan Saring, did a wonderful job of creating a C# UI for the viewer using the MONO project framework. If you can use that, please do so – the UI is much easier to use than the text mode utilities here. I found getting Mono to run a little awkward, and I wanted automatic generation of web pages (see project HTML Tree), so I wrote an extension to the srd utilities to get the job done. (more…)

If you want to read up on the file format of HRM files, or if you want to contribute to decoding them, please check here.

Half Dome Trail, Yosemite, CA

{moszoomimglink:Nothing stops you for}Yosemite in the early summer is a wonderland of incredible beauty. The wildflowers are still in bloom, the waterfalls are strong and powerful, and the temperatures are high enough to allow for a quick dip in the water. What better time to explore a great day hike than this?


Four Mile Trail, Yosemite, CA

{moszoomimglink:First view of Yosemite – El Capitan and Half Dome}Have you ever gone to Yosemite? Well, I had been living in California for years before I took the time and drove there. It was a chilly autumn morning, the leaves were already brightly turning and I had nothing better to do.

I left early and stayed no time. To a certain degree, I only wanted to say I had been there. Tell myself, that is, since there was nobody else who would have cared.

A year later, it was Thanksgiving, I had just come back from Hawai’i. My housemate surprised me by saying he had rented a room at Yosemite lodge for the holiday, just to escape the cooking. We would drive up on Thursday morning, have dinner at the lodge, and maybe do a hike or two.

{moszoomimglink:El Capitan}Things worked out beautifully. It was unseasonably warm, maybe five degrees above average. We got there in the early afternoon, went on a short hike to Vernal Fall and had dinner at the main restaurant. Mountain air, excellent preparation and the comparison with home cooking made it a real feast. The room was understandably full, but waiting times were close to nil – reservations were not required.


Kilauea Iki Crater, Big Island, HI

The Big Island of Hawai’i is famous for its volcanoes. It actually is not one, but five volcanoes that are joined by overlapping lava flows. They vary in age and activity, and the youngest and most active of them has been the center of attention ever since mankind reached the islands.

{moszoomimglink:It was really flowing} Kilauea means spewing, and no volcano on Earth could be as true to this name. Kilauea has been spewing incessantly since 1992, and to this day you can hike up the brank new lava and see the red flow coming down the mountain.

{moszoomimglink:From Jaggar museum, looking into the caldera} The summit area of Kilauea is currently just a hickup in its much larger sister mountain, Mauna Loa. A dozen or more craters are lined up in an amazing cluster, the most prominent being the Kilauea caldera itself, a gargantuan gaping hole in the ground, with another smaller but deeper hole, Halema’uma’u, considered to be the house of the volcano goddess, Pele.

Slightly to the East of Kilauea is a much smaller, but still very impressive crater known as ‘Little Kilauea’, or Kilauea Iki. This crater has been dormant for a few decades, but was the location of the most amazing eruption of 1959, when a gigantic fountain of lava shot out of the side of the crater, filling the crater until it had turned into a lava lake. The eruption then stopped and moved to another vent, but the lava was trapped and took a few decades to cool down for real.


Haleakala Crater, Maui, HI

{moszoomimglink:12-49 Focus on the cloud and the sky turns blue} Maui is made up of two volcanoes joined at the hip by a low-lying valley. The Western volcano, aptly named ‘West Maui Mountains’ is old and weathered, while the Eastern one, Haleakala, erupted as recently as 1790.

Haleakala is a gigantic presence in the backyard of Maui. Its gentle slopes carry nature from the tropical paradise of the Hana coast to a harsh, almost Alpine summit. In between, you’ll find cowboys tending herds and flower farms, wild rivers and incongruous deserts.

The grandest sight, though, is the crater itself, the summit of the ancient volcano. It is witness to the power of nature: the destructive power, but the power to transform even mere rock into items of beauty.

This is a fairly long hike either in the cold clouds or in the blazing sun of 10,000 ft. You must be prepared to both, and pack clothes covering your whole body, sunscreen, food and plenty of water. Remember: the weather shifts very quickly, and you may end up sweating on one section just to freeze on the next one!


Awaawapuhi Trail, Kauai, HI

Reading up on Kauai you get easily turned on by descriptions of its marvelous natural beauty. They call it ‘the Garden Isle’, and it is so special that even Hawaiians will trek out there to visit. Kauai is the backdrop for innumerable movies as well as the scenery behind a great many honeymoon pictures.

{moszoomimglink:21 Kalalau Valley from high above} There are plenty wonderful hikes in Kauai, from short paths to a lighthouse to multi-day excursions to Kalalau Valley, a miracle of inaccessible beauty. A great many wonderful hikes are concentrated around Koke’e state park, on the West side of the island, up on the mountain that forms the core of Kauai.

Of all the hikes in Koke’e, then, the most spectacular is the hike on the Nualolo / Awaawapuhi trails. You’ll get to see scenery and colors you won’t find anywhere else; you’ll walk on a razor’s edge with nothing on your side for a thousand feet; you’ll walk under a gentle waterfall; you’ll be standing on top of a vertical cliff so scary, it will make you think twice before you follow my advice again!


The Big Island

{moszoomimglink:Waipi’o – tiny Hi’ilawe falls} I am writing this fresh from a one week vacation to Kona, spent mostly exploring and marveling at the miracles of this biggest of the Hawaiian islands. It is so big, indeed, that it would easily fit all other islands combined.

{moszoomimglink:All of Mauna Loa} Like all other islands in the chain, Hawai’i is formed by volcanoes that rise up all the way from the bottom of the sea. While underwater, the lava cools very quickly, generating a mountain that is very steep. Once the ocean surface is passed, the lava turns out to be very fluid, so that the aerial part of the islands is quite flat. Don’t expect the volcanoes to look like Mount St. Helens or Vesuvius: they are gentle in slope, and the only really steep grade is where erosion has eaten away a chunk of mountain.

{moszoomimglink:Kohala} The five volanoes that comprise the island are very different in nature. Kohala, the oldest, is weathered and looks already a little like Kauai: deep valleys on the windward side, dry shrubland on the leeward side. Mauna Kea, the next oldest and highest point in the state of Hawai’i, is the steepest of them all, looking on a clear day like a dome. Hualalai, which dominates Kona’s skyline, is not really very remarkable. Mauna Loa, just a hundred feet shorter than Mauna Kea, is so huge in mass, you barely notice it has a slope at all, looking at it from a distance.

{moszoomimglink:It was really flowing} The fifth volcano is the reason most people want to visit the island: Kilauea is the most active volcano on Earth, and on a good day you can actually see the lava flowing almost under your feet!

As for my personal impressions: Hawai’i is evidently the poorest of the main islands. Some areas (such as East of Hilo, in the Puna district) are so depressed you can barely tell the cars from the volcanic soil that turns rust red after a few millennia. And when you talk with people, they all tell you they’d rather live in Kauai, Oahu, or Maui, but – alas – can’t afford those places.

Now, being poor in Hawai’i is still better than being poor anywhere else, and I love how genuinely happy everybody seems. There is no fake smile for tourists, but I have seen none of the ‘stink eye’ that so many guides mention. And I have seen it all, having toured the island four times in nine days.

{moszoomimglink:Lava black, rest in the sun} Highlights? If you visit, you MUST go to the volcano. If you come back and tell me you haven’t seen it, I’ll ship you right back via FedEx. You just can’t imagine how it feels when you look into a crater whose floor is a frozen lake of lava that still steams. What was a downside to me my be an advantage for you: I found it all too manicured and perfect, with trails that had signs at every crossing, and roads that must be the envy of any San Franciscan (or New Yorker).

{moszoomimglink:The bottom is paradise} Second, pick one of Pololu or Waipi’o valleys to get a glimpse at what a lush tropical valley looks like. Most books favor Waipi’o, but I find Pololu to be more accessible, just as beautiful, and much less crowded. Wouldn’t you want to hike down a trail that passes a guava forest, and a jungle on the way to the next valley?

{moszoomimglink:It is turning dark} Finally, if you have even the slightest interest in Hawaiian culture, history and art, you have to see the Puuhonua o Honaunau, an ancient temple complex South of Kona. You have to go, and you have to walk on the lava shelf and bathe in one of the pools formed by the tides.

{moszoomimglink:Sunday triathlon 02 start} Of course, the biking situation was a big hit for me. And I found dozens of bikers and triathletes on the Kona side – from the pros to the amateur. The town of Kona is full of souvenir shops, the promenade in front of my hotel was crowded in the morning with two dozen triathletes meeting for a training ride, and Queen K, the highway to Waimea, was at all times of the day frequented by a few riders. Nothing like Foothill Expressway, of course, but good enough to keep me interested. Unfortunately (for me, not for the triathletes) the island is fairly flat and the roads barely make a nudge to the up or down.


Oh, what a surprise! You won’t know what you missed in life until you got to Kauai.

{moszoomimglink:Wailua falls}The Northernmost major island of the chain, Kauai is the one that gets the most water. It is the oldest, too, so that the flanks of the volcano that makes up the bulk of its mass are eroded into deep valleys with sharp razor-edged mountain ridges to separate them. There is, as usual, a wet side and a dry side to it. The wet side is so wet, it is famous for being the wettest spot on Earth. Mount Waialeale is not the highest point on Kauai, but surely the wettest. I am positive that Waialeale must be Hawaiian for “watch out, it’s slippery!”

{moszoomimglink:04 Kirk Mark and Camy having fun}The dry side is home to Waimea Canyon, the Grand Canyon of the Pacific. Looks nothing like the Grand Canyon, but it’s really a wonderful sight. Additionally, you’ll have the pleasure of an immense beach on the dry side. Polihale beach goes on and on for miles and miles, one of the few such beaches on the islands.

There aren’t many real sights on Kauai. There are no real cities, but the charm of a few of those that try to be is infinite. My favorites are no doubt Hanalei in the North, Kapa’a in the East and Koloa in the South. Waimea at the mouth of the canyon is supposed to have similar charm, but a quick visit would not confirm.

{moszoomimglink:28 The ditch gets deeper, the soil redder}And yet… Nature is at its best here. The soil of the island is rich in volcanic iron, which gives it a splendid rust red. Imagine an island of rust offset against tropical greens of plants that feed on the minerals and the plentiful water. And now imagine these reds and greens against a sea of blue and turquoise and deep indigo. The sky plays with its pinks and oranges and whites of clouds. You end up with a canvas of nature, with every place having a magic to the eye that is unrivaled except by itself in a different light.

{moszoomimglink:50 Light shining on the valley floor}To aid nature’s colors, the scenery is astounding. The deep, deep erosion that characterizes the island has produced some of the most varied topography imaginable. In the Southern end of the island you still see how the volcano was once shaped, a flat dome that deserves is scientific name of shield volcano. But right then and there you see how the shield suddenly drops into Waimea canyon, a chasm that goes almost all the way to the sea.

{moszoomimglink:Who would believe these colors are real}If you can, spend all the time you have on seeing nature. Book a helicopter tour, a sailboat tour, a hiking tour. You need to see it to be able to say it was worth it. And once you have seen Kauai, you won’t be able to imagine a more beautiful spot on Earth.


{moszoomimglink:A stream falling into a pool}Maui-no-ka-oi, Maui is the best! That’s the motto of the island, and funny enough, it seems consistently not to be true. Maui is always second best at whatever it is good. It is the second-largest island; it is the second densest in population; it is the second highest; it is the second most urban; it has the second-best nightlife and the second best shopping; nature is second best, as is the diversity of the people.

{moszoomimglink:Coastline on the way to Hana}Overall, though, Maui could be the best. Its free-wheeling spirit makes it more Fun than the other islands, and its natural attractions are close to human life and concentration. Kilauea beats Haleakala any time as a volcano, and the famous Road to Hana can’t beat the Na Pali coast on Kauai – but you can’t actually see Kilauea and Na Pali on one day.

{moszoomimglink:Just another marvelous lava cape}Maui is probably the best spot if you are an all-around person that loves to have fun. You can go and have breakfast in Lahaina and stroll around shops (not my favorite thing to do, but it may suit you), then leave to tour the West Maui side and see the Blowhole and Kahakuloa. Or you can skinny-dip at Little Beach, body-surf at Big Beach and finally snorkel like the champions in the Aquarium, which you’ll have to reach through a vast lava field hike. How about the famous Road to Hana? You drive for hours and hours behind mooning tourists from Ohio and elderly Californian widows, but you see tropical forests and waterfalls as you’ll never see them again in your life.

{moszoomimglink:12-26 Streaks of colored sands merge at the bottom}Whale watching anyone? Dolphin hopping? Turtle seeing? Sunset cruises, parasailing, and even a decent meal or a fun dance bar in Kihei, that’s all included in a vacation to Maui. And if Haleakala is four thousand feet shorter than Mauna Kea — who cares, it is mountain enough for all of us, and the hike through the crater (which you can’t do on Big Island) is one of the more mystical experiences you can get.

{moszoomimglink:La – a sliver, really, if you look right}A few words of warning: the bicycle cruises from the top of the volcano are really only for people who don’t like biking. For those who do, the whole affair is immensely boring and marred by the fact that you start at 40F and end at 90F. And when you go to see the sunrise from the top of the volcano, hope that some handsome boy from Minnesota proposes to his charmingly curvvy high-school sweetheart when the sun comes up. It makes the wait and the freezing temperatures worth it.

Oh, and since it’s about me: biking on Maui is fun!

The East Coast

I confess, after Hanauma Bay everything else is a bit ‘so-what?’ You leave the parking lot, look again at the cinder cone and drive on to a long sandy beach. Here I noticed for the first time how quickly the climate changes: you start out in green and lush Honolulu, and here all of a sudden the scenery turns arid, grey, inhospitable. The beach is beautiful and the views of nearby Molokai can be impressive, but you feel like on a desert island.

{moszoomimglink:Jumping dolphin}Past a blow hole and a wonderful body surfing beach, you’ll finally get around the East cape to a greener area. Turns out that the wind predominantly blows from the North-East, so that the exposed side gets all the water. You just drove around the South-East side, which is not exposed (and hence dry). Now you get to see all the water you were always afraid of — on every one of my visits, the East side was quite cloudy with dense dark formations.

You may want to visit Sea Life Park, which has fun shows and lots of fish and marine life. It has a remarkable deep water tank that is full to the brim with sharks, tropical fish and other marinery. There are two dolphin shows and a penguin show, and although I am a cynical European by birth, I was impressed by the grace of the presenters. And seeing a dolphin swim is still a marvel to me. So it gets my vote.

{moszoomimglink:Bridge to the Byodo-In temple}Driving farther, you’ll drive with steep cliffs to your left and the sea to your right. The cliffs (pali in Hawaiian) are a barrier to the moisture and are to be blamed for the clouds. Drive past Kaneohe, and turn left to the Valley of the Temples. This is a remarkable place of worship, where Hawai’i decided to cluster churches, shrines and temples of all religions imaginable. Of all of them, the Buddhist Byodo-In Temple is the most remarkable — a reproduction of a shrine in Japan, it alone is worth the trip to the East coast.

Driving farther up, the plain that separates the mountains from the sea shrinks to the point where tunnels needed to be bored through the former. Hiking paths crawl up the valleys and the spines of the ridges, and Hawaiians come here to celebrate a weekend family trip. Here Oahu is the tropical paradise I wanted to see, with wild banana groves, clusters of papaya and coconut palms.

{moszoomimglink:The Tonga drum show}The plain appears again, and human settlements. A huge Mormon something (place of worship? university?) fills up the hills to the left. Then the Polynesian Cultural Center, a giant affair that tries to explain what Polynesia is about, how Hawai’i fits in and why it is important to preserve cultures. Most people come out of it with a vague idea that Polynesia is about very pretty girls in skirts smiling their facial muscles to a freeze and very handsome boys in skirts drumming their arms to Schwarzenegger proportions. Particularly annoying is the cascaded show effect: since the shows are well announced and in sequence, the throng follows the path of the shows making all but the active show empty. As a result, the park appears either full or completely empty.

{moszoomimglink:Cliff diver jumping from the falls}You reach the North end of the island, famous for the waterfalls of Waimea and for Sunset Beach, allegedly the best surf on Oahu. The former is a really beautiful park-cum-waterfall-dive-show; the latter fun if you are under 30 and want to hang out. I was blessed with calm seas during my visits, which means most surfers were just sitting on their boards, chatting of girls and beer and letting their legs hang from the board as shark bait.