Physiology of Cold

Sandy beach run in San Francisco — almost like real training

Today I headed out to Stanford University to give a video interview about physiological responses in cold-weather endurance events. Beat and I were both recruited to give some experiential insight for an online class called "Your Body and the World: Adapting to your next big adventure." My kind of class! The instructor, Dr. Anne Friedlander, has been conducting all kinds of research into exercise physiology in extreme conditions — dunking her TAs in an ice bath, having them exercise in heated rooms. Like I said, my kind of class. 

Dr. Friedlander also is interested in having me be a guinea pig for her scientific research, toting a core temperature reader and heart rate monitor in the Iditarod Invitational. I really want to do this; I hope it works out. I've long hoped that more scientific research would focus directly on ultra-endurance sports — it's fantastic that Stanford is involved, and I'd love to be involved as well. Beat was unable to attend the interview so I had to hold down the fort. I was really nervous, so I made a few notes based on some practice questions she sent me. The interview went well I think, and my notes provide a bit of an intro into something people often question me about — "Why do you like cold-weather racing so much?"

1. It sounds like you didn’t even ride a bike until your early 20s; how did you get into ultra-endurance bike adventures? 

I started hiking as a teenager, and did quite a bit of hiking and backpacking as a youth. Around age 22 I picked up cycling because I wanted to try touring, or traveling by bicycle, and found that I loved the simplicity and ease of movement on a bike. When I was 26 I moved to Homer, Alaska, to work for a newspaper. We moved there in September and I realized that if I didn't pick up a cold-weather outdoor hobby, I was probably going to go crazy during the long, dark winter. I considered skiing, but then I discovered that some cyclists up in Alaska rode throughout the winter, on snow-covered trails. Shortly after that, I learned about the Susitna 100, a 100-mile endurance race on the Iditarod Trail. At the time I wasn't really an athlete; I didn't train and had never competed in a race of any sort. But for reasons still unknown to me, the Susitna 100 captured my imagination. Everyone who knew me thought I was nuts to jump into an event like that off the couch, but suddenly I had this wonderful excuse to go out for bike rides at night, in blizzards, at 10 below. Every day was a new adventure. I loved it. The race itself was unbelievably difficult. Trails were soft, and then it rained, which turned everything to slush, and I couldn't ride my bike at all. I was walking, I was soaking wet, and it was still 33 degrees outside, not warm. I was borderline hypothermic for hours, pushing and shivering, wavering between wanting to hit a panic button and just sitting in the snow and giving up on life. But I made it. I finished in 25 hours. It was the worst thing I had ever done to myself, and at the finish line I announced "never again." But I was smiling. And, of course, I was hooked.

2. Why are you so drawn to races in the cold?

This probably sounds insincere from someone who chooses to live in one of the friendliest climates in the United States, but cold weather is my favorite weather. There's something magical about the subzero range; the air is often so clear that far horizons become visible, details appear sharper, the low angle of the winter sun casts the world in golden light, and snow sparkles like a sea of shattered glass. When there's no wind, a deep quiet settles over the land, and any sound becomes crystal clear. Sometimes in subzero temperatures, I can stop on a wide-open plain and hear footsteps from an animal that I can't see — something that's probably a half mile away, but sounds like it's walking beside me. Also below zero, ice crystals in the air make a tingling sound, like tiny bells. It's such a beautiful, surreal setting. There's also a life-affirming value to extreme cold — it's a death-like environment, and yet I am very much alive, moving freely in my own self-contained bubble of warmth and life. 

3.  What are the primary things you need to consider when racing in the cold as opposed to “normal” ultra-endurance racing?

Your primary consideration is regulating core temperature. You of course don't want to let your body temperature drop into hypothermic ranges, but you have to avoid overheating as well. During strenuous exercise you output a lot of heat, even in extreme cold, but at the same time you have to wear insulating clothing to keep your skin and extremities from cooling too much. The result is that you're going to sweat, and if you don't vent the moisture, it will collect in your clothing and freeze, diminishing the insulating properties and turning your body into a human snow-making machine. Having a system that's too well ventilated, or too light in insulation, can be dangerous as well, as you will burn up a lot of energy making heat while increasing your risk of frostbite. Finding that balance is extremely difficult, especially over extended periods of time. I've played with a lot of different gear set-ups and found that, at the end of a long day, my base layers end up soaked no matter what I try. So I opt for a "warm when damp and windproof" system of synthetic layers and Gortex, and carry a big down parka for instances when I need to stop moving for more than a minute or two. 

4.  What do you notice about your performance and physiology when racing in the cold?

The first thing I notice is how directly temperature affects my speed — the colder it is, the slower I move even when I feel like I'm expending the same effort. I suspect this happens because muscles never fully warm up — like an old car engine sputtering down the street on a frosty morning. Subzero temperatures definitely diminish my performance no matter how good my gear is. But at the same time, this adds to the challenge and thus the intrigue. 

5. What are some of the scariest situations you’ve been in during these cold adventures?

During the 2009 Iditarod Invitational, while crossing a frozen lake just 25 miles in, I punched through some thin ice and dunked my right leg almost to my hip joint. At the time it was about zero degrees with a strong wind, and the temperature was plummeting. I opted to get off the lake and into tree shelter to deal with my wet boot, but by the time I got there, my whole leg was encased in ice. So I made a second poor decision to continue onto the first checkpoint, which was still 30 miles away. The snow was soft and travel was slow. I would ride 10 minutes and run for 2 or 3 in an effort to keep my feet warm, but temperatures dropped down to 35 or 40 below according to others who were out there. When I reached the checkpoint, all of the ice in my boot was frozen solid with my foot inside. By the time enough ice finally melted to get my foot out, my right foot was chalk white. Rewarming my foot was one of the most painful experiences I've ever endured, and afterward blisters and black spots formed on all of my toes. I had to drop from the race, and it took several months to recover from frostbite. I still have nerve damage from that, five years later. 

There were times that I bivied in the snow, when I was so tired and the air was so cold that I felt deep and terrifying anxiety that I would fall asleep and never wake up. But the single scariest moment was perhaps during the 2011 Susitna 100, which Beat and I ran together, on foot. Temperatures had been cold all day, probably never warmer than 5 below, but we were running fairly hard and were dressed very light. When the sun set, temperatures plummeted and the wind really started cranking. We turned onto the Susitna River to face a full blast of wind and a chill that later was estimated at 50 below. I went from feeling comfortable to desperately cold in a matter of minutes, and still I waited just a few minutes too long before I finally stopped to dig my down coat out of my sled. Those few stalled minutes were enough to send my core temperature into a nose dive. I'd removed my mittens to grab my coat, and my hands froze almost immediately. They were rigid, like a claw, and useless. I got my coat on, but couldn't zip it up. I felt very cold and I was nearing panic. Beat was there and helped me zip up my coat. If I had been alone, things would have probably gotten worse before they got better. It was an important reminder about how quickly one's condition can change out there. You really have to stay on top of every little thing. 

6. What drives you to keep pushing your limits and putting yourself at risk in these ways?

I relish in the experience of being alive, and nothing makes me feel more intensely alive than seeking the edge of livability and peering out into the void. Pushing my body to its limits in a cold environment, a place where there is no margin for error, has an intensity of experience that makes it seem as though I've lived a lifetime in a matter of days. When I emerge on the other side, it feels like years have passed and I've changed and grown as a person. At the same time, I relish in the simplicity that endurance racing evokes. Like anyone, I have my petty worries, my irrational fears, my pessimistic world views and my existential despair. A hard endurance effort strips all of that excess away, exposing the basic core of who I am. By necessity, I have to let the abstract thoughts go and focus on the immediate. What will I eat? Where will I sleep? How will I get through this storm? I revert to a basic animal state, which is not only liberating, but also casts a brighter light on the parts of life that are truly important to me. 

7. What adventures or races do you have planned for the future?  Or what’s on your bucket list for that matter?

Well, of course the 350-mile Iditarod Trail Invitational in February, which I plan to race with or near Beat on foot. And beyond that — I'd love to do some winter bike touring in remote locations. Greenland, Iceland, Finland, and Baffin Island are all on my wish list. I'd love to visit Antarctica. I don't need to bike there or go to the South Pole — I'm not sure I would enjoy an expedition of that length — but just experiencing Antarctica would be a dream. And then, of course, the 1,000-mile ride to Nome. Beat thinks I should go this year, but I'm not ready. I need to gain more fresh experience first. I haven't lived in Alaska for three years, and I'm definitely getting rusty on the whole cold-weather endurance thing. 

Week 4, Dec. 2 to 8

Monday: Run, 1:27, 8 miles, 1,342 feet climbing. I flew out of Salt Lake City in the early afternoon, but was able to squeeze in a 90-minute trail run with my dad before I left town. We ran an out-and-back on the Bonneville Shoreline Trail in Corner Canyon, which he'd never run or hiked before. Despite spending the rest of the week in California, Monday was by far my warmest day, with temperatures near 60 degrees and a strong warm wind out of the east.

Tuesday: Run, 0:54, 5.8 miles, 614 feet climbing. The standard Tuesday run — Monta Vista loop between 4 and 5 p.m. I like having one workout that's exactly the same every single week. In future weeks I might try to designate Tuesday as a rest day. I finally changed out my shoes this week, a pair of Hoka Mafate 2s that I've had for a while but were nearly new. And the pain on top of my left foot went away entirely. I suppose I was right about the theory that my Mafate 3s were worn out.

Wednesday: Road bike, 2:27, 33.5 miles, 3,719 feet climbing. I was woefully underdressed for this ride with temperatures in the low 30s and a downhill windchill that must have approached 20 degrees. I know I'm California soft now, but this had all of the hallmarks of extreme cold training, with numbness slowly creeping all the way up my extremities, involuntary shivering, and a dramatic drop in core temperature that took most of the evening to recover. I forget just how exhausting this process is — the rewarming took more out of me than the ride itself. It was a useful reminder for real winter conditions, to always stop and deal with body chill before it gets out of control — it's not only dangerous, but it's also a massive energy drain.

Thursday: 0:57, 6.3 miles, 942 feet climbing. For this run I met up with Chris, who is a San Jose local that I met on the flight to Salt Lake City last week. We spent the whole 2.5-hour flight talking about Bitcoin and growing up in Utah. Yes, I sat next to someone on a plane and actually made a new friend. I am not a chatty person, so this was a new experience for me. Chris is a triathlete and mainly a road runner, and I was hoping to draw him to the light side of trail running with my favorite 10K loop in Rancho while heavily talking up a 50K race in Woodside. Maybe I'll see him there on Sunday.

Friday: Run, 1:55, 10 miles, 1,988 feet climbing. I drove out to El Cerrito to meet with Ann Trason, and before our coffee date we went for a run in the Berkeley Hills. She's laid back and a lot of fun to

run with, especially after we got lost and had to crawl up a super steep, cow-stomped slope. She told a few great stories during the run but then admitted she doesn't like talking about herself later that afternoon. If we ever end up doing formal interviews, they'll likely be best on the move.

Saturday: Run, 6:27, 23 miles, 5,232 feet climbing. Pacing for 9 miles and then rambling on my own for another 14 in the Marin Headlands, at a mellow pace all around. But after standing around for much of the morning at the Stinson Beach aid station, it was a decent day on my feet, which I think is the best kind of physical Iditarod Training. There was even a strong, cold wind on the ridge tops to simulate Alaska just a little.

Sunday: Road bike, 1:46, 17.7 miles, 2,495 feet climbing. Beat played with the Snoots and I enjoyed a leisurely climb. It was another clear, cold day, with near-freezing temperatures on top of Montebello. Beat and I both brought our windproof fleece jackets to test on the descent. I admit I had to put mine on two thirds of the way up the climb, because I was too cold. We still didn't wear adequate gloves, tights, or footgear, so we still froze on the descent, although not to the extent of Wednesday. I'm definitely California soft now, but I feel like I got some real cold-weather training in this week. I also had a chance to run with several new and interesting people, which was a fun diversion from my usual solo style.

Total: 15:53, 53.1 miles run, 51.2 miles ride, 16,332 feet climbing

Beat is traveling to Germany this week to attend his step-father's funeral. My goal for this coming week is, of course, the 50K trail run on Sunday, and then perhaps a long ride on Monday. I want to start incorporating some back-to-back long efforts without the risk of ramping up running mileage too much. I'm also giving more thought to the whole tire-dragging thing, but I don't think I can deal with being that conspicuous on local trails. I wish there was a way to simulate sled dragging in a snowless climate without looking like an idiot. A heavy backpack on hills might work.  

A distant goodbye

Just as a corporate championship race with more than a thousand participants was drawing to a close, I was a half dozen miles away on the Coastal Trail, a solo runner among the otherwise stoic cliffs. Earlier in the day, I hopped a shuttle bus and spent several hours among the crowds at Stinson Beach, cheering for runners in the North Face 50-mile Endurance Challenge — because it's fun to spectate a big race. Then I helped pace an acquaintance from Colorado who unfortunately was having a bad day and missed a cut-off at mile 36. After that, there wasn't much left to do but run back to where I started, so I took a long way, meandering along the high ridges of the Marin Headlands.

A cold wind blasted the cliffs, carrying a salty mist hundreds of feet above the crashing waves. The setting sun rendered the hillside in purple light and sharpened the chill, which, thanks to the wind, felt more threatening than the mild temperature might imply. I rounded a corner and caught a gleam from the last light of the sun in the eyes of a young bobcat, who stared at me for a long second before turning around and sauntering down the trail. Bobcat was running but with no real urgency, its long legs and big paws stirring a fine layer of dust that had been kicked up by hundreds of runners early that morning. A couple of times, the bobcat glanced back as if to say, "Are you still following me? This is my trail." I love spotting bobcats in the hills; they remind me of my imagined spirit animal, Lynx, which I conjure for comfort in times of fear and pain. After the bobcat finally darted back into the brush, I decided our brief run together was a good omen.

A few hours later, Beat texted to tell me that his mother's partner Peter had died. It was not unexpected; he had terminal cancer, but the quickness of his passing came as a surprise. And regardless of the circumstances, it's never easy to accept that someone you knew and appreciated is suddenly, simply, no longer there. When Beat and I visited his mother in Germany, Peter and I would occasionally take long walks on the paths and trails of Bielefeld. He spoke only a little English and I speak even less German, but he used our limited shared vocabulary and enthusiastic gestures to piece together a compelling portrait of the city and his life there. He was kind and intelligent and always had a sparkle in his eye, a zest for life that even a crescendo of near-constant pain couldn't dampen. He was fond of aphorisms and walking. Peter was once a very quick marathoner but unfortunately a longterm smoker; complications of smoking nearly took his legs, but he was able to save them through sheer determination and exercise. He walked nearly every day, sometimes 20 or 30 kilometers, and it was difficult to watch as cancer took this joy away from him as well. He was always supportive of Beat and me and enthusiastic about all of our crazy adventures; he treated me like a daughter-in-law despite the lack of legal definition, liked all of my Facebook posts, and greeted me with a long-armed embrace whenever we visited. And Peter absolutely adored cats. I thought about the running bobcat when I learned he was gone. Peter would have loved that story.

I will miss him.

Saturday was a beautiful day. After a deluge of rain on Friday night, the morning dawned clear and cold, with pre-dawn temperatures again hovering near freezing. I headed out to the Headlands to meet up with Shelby, a woman from Colorado who traveled to San Francisco to take part in the North Face 50, which is largest and most prestigious trail race of the year in this region. I think they have something like 500 sign-ups in each of the 50-mile, 50K, marathon, and marathon relay races, including a large number of elite and international runners. If you add in volunteers, pacers, crew, and sponsors, you have well over 2,000 people involved. Those are big numbers for trail running, which is the main reason I never sign up for this event. But then December rolls around and all the excitement drums up and I want to get involved. Shelby invited me to pace her from Stinson Beach to the finish, about 22 miles. Sadly, her stomach turned shortly before we linked up and there's not much I could do to help but sympathize. We reached the Muir Woods checkpoint just five minutes late, but it was a hard cut-off. Shelby, who's a little burnt out after a long season of racing, was cheerfully accepting of the outcome, and grabbed a race shuttle back to the start. Since my car was parked at Tennessee Woods, I decided to continue on the course and added a bonus loop after the stars came out and the cold wind really started cranking. I loved it, even though I missed most of the race action.

Also on Saturday, I was drawn in the lottery for the Hardrock 100, a 100-mile mountain run in the San Juan Mountains of Colorado next July. That text from Beat came a couple of hours before the one about Peter, as I was cheerfully running down the Marincello Trail to wrap up my long run. My response was a blunt but succinct "WTF?!?" Because of the way Hardrock divides up their entries, there were 1,010 people vying for 35 spots. Every year a runner signs up for the lottery, they're given an exponential increase in the number of "tickets" they receive. This was my second year giving it a go, so I had two tickets. People who have tried for years with no luck can have upwards of 128 tickets. Needless to say, I did not have a high chance of "winning." And if you want to increase your chances each year, you have to play the game. With only two tickets and the possibility of increasing that to four next year, I threw my name in the hat.

It was drawn. I very much want to run Hardrock. I would be a great adventure run, in one of the most spectacular mountain ranges in the United States, and the organization itself creates a family-like atmosphere that one can't help but embrace. And its very inaccessibility in terms of entry has contributed to Hardrock becoming perhaps the most widely coveted 100-mile mountain run in the world. All that said, I was forming other adventure ambitions for the summer of 2014, and Hardrock just doesn't quite fit. I might be able to make it all work with excessive adventure greediness, perhaps demanding the impossible from myself, and of course even that would be a grand experiment. Either way, I'll have to do some serious soul searching about this in the coming weeks. It would be unwise to give up what will likely be my only chance to run Hardrock. Just qualifying for this run is a whole lot of commitment that I'm not willing to wedge myself into — training for and running the same 100-mile races every year.

This has certainly been my year for race lotteries. A few months ago I applied for the White Mountains 100, thinking, "I don't really want to take on a 100-mile snow bike race so soon after the ITI, but it's my favorite race ever and I'm not going to get in anyway." I got in. Now Hardrock. It's almost as though the so-called "lottery gods" are testing the conviction I had back in September that maybe I should dial back the whole adventure racing thing, that maybe it's getting out of control ...

It's a good problem to have, of course — too many things I really want to do with my time. The problem lies in wanting to have it all.