Forerunner 235 Heart Rate Monitor vs Chest Strap

I’ve been experimenting with the wrist-based optical heart rate monitor that’s built into the Garmin Forerunner 235, and wrote about it previously here. To test it further, I recently did a 90 minute easy run with the Forerunner 235 on one wrist, and a Forerunner 220 on the other, linked to a Garmin HRM3 heart rate chest strap. This particular chest strap has served me well for several years, so it provided a reliable baseline for comparison with the FR235 heart rate data.

The results weren’t good for the FR235. The graph shows the HRM3 data in red and the FR235 data in blue, and it’s obvious at a glance that there were very large discrepancies. The first 15 minutes were broadly OK, with some small deviation between the two HR measurements, but things fell apart quickly after that.

So what happened here? It looks like there were two brief spikes at 15 minutes, where my HR as measured by the chest strap reached 148. This brought it close enough to my cadence (low to mid-150s for my plodding) that the FR235’s sensor began responding to optical changes related to cadence rather than heart rate. This is a phenomenon called cadence lock, and it lasted for more than 30 minutes, even as I intentionally reduced my effort in an attempt to separate current HR further from current cadence.

Eventually I grew tired of waiting for the FR235 sensor to self-correct, so I slowed to a walk. After two minutes the HR measurements were finally back in sync. But when I resumed running, the problem immediately reappeared. What?! I tried changing my pace and stride length to see if anything would make it self-correct, but nothing helped.

In desperation, I tried tightening and loosening the FR235 strap, and moving it up and down my arm while I continued to run. At the 55 minute point, I found a spot midway up my forearm that seemed to work better, and the FR235 HR readings returned to normal.

Is it just a question of finding the magic spot on your arm, then? Sadly, it appears not. Even with the watch at the “good” spot on my arm, the FR235 HR data showed many odd spikes over the next 20 minutes, between the 55 and 75 minute marks on the graph. And then I reached the final uphill section of the run, and the FR235 HR measurements again became permanently confused while I trudged up the slope. Something about my change in stride on the uphill seems to have triggered cadence lock once again.

It’s interesting to see several places where the shape of the FR235 HR curve is correct, even where the absolute value is wrong by 10 bpm or more. Some noticeable examples of this are at 17 minutes and 52 minutes. I can imagine the watch firmware trying to make sense of two conflicting signals, one from heart rate and one from cadence, and somehow combining portions of the two rather than locking on to one or the other exclusively. It’s surely a difficult problem to solve. Unfortunately for me, the FR235 doesn’t solve it very well. Results can be very different for different people, so maybe you’ll have better luck.

Forerunner 235 Optical HR Sensor Problems

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Arghh, heart rate monitors! They’re temperamental beasts that never seem to work correctly. The Garmin Forerunner 235 has a built-in optical heart rate sensor at the wrist, which promises to make HR measurements more convenient and comfortable than with the old-style chest strap. Unfortunately my testing has found the FR235’s wrist-based HR measurements to be wrong by 10-30 bpm often enough that it’s of limited use for tracking my running.

An optical HR sensor works by measuring tiny changes in the reflected light from your wrist veins with each heartbeat. It’s not quite as accurate as the electrical measurements from a chest strap, and it can sometimes be thrown off by other sources of changing light, but ideally its convenience will make up for those shortcomings. Before purchasing the FR235, I read several reviews that focused on its optical HR sensor, especially DC Rainmaker’s excellent review. The consensus was that the FR235’s optical measurements were generally within a few beats per minute of a chest strap’s measurements, especially for runs at a fairly constant effort level, which describes most of my running. The only place where the reviews identified a significant problem was when doing hard interval repeats, where the FR235 would sometimes take too long to recognize when HR had gone back down at the end of an interval.

 

Intervals

After a few weeks of running with the FR235, I can only wish it worked half as well for me as it did for DC Rainmaker. When running intervals, it doesn’t just lag with the HR decline at the end, but typically misses the interval completely. Here’s a workout I did recently, where I inserted some short sprints at 5:30/mile pace into an easy run at 9:00/mile pace:

hr5

Five sprints are easily visible as sharp spikes in the blue pace graph. For the first and third sprints, the HR measurement from the wrist-based optical sensor barely changed at all. Looking solely at the HR data, you would never have guessed an increase in effort had occurred there. The fifth sprint showed a more gradual increase in HR accompanying a gradual increase in pace, but no HR response from the sprint itself. Only the second and fourth sprints showed a HR response more like you would expect, with a sudden increase in HR, but even there the HR didn’t spike very high. Contrast this graph with a similar workout one month earlier, using a chest strap for HR data:

hr6

With the chest strap, each of the six sprints is accompanied by an obvious spike in HR that reaches 160-170 bpm. The HR response to the sprints looks completely different than in the data from the FR235’s wrist sensor.

 

Cadence Lock

I knew intervals would be a problem for the FR235’s optical sensor, so I can probably excuse this. But what about easy runs at a constant effort? A HR sensor can be useful for ensuring easy runs stay truly easy, if you have a tendency of pushing them too hard. Unfortunately the FR235 frequently fails there too. At least once or twice a run, I’ll be moving at a very easy pace that I know should put my HR in the mid-130s, but I’ll see a HR number in the mid-150s. So I’ll slow down and take tiny little steps, only to see the HR number increase even further into the 160s. Finally I’ll slow to a walk, but the HR number will stay in the 160s before abruptly dropping to the 120s. What seems to be happening is that my cadence (steps per minute) is close enough to my HR (beats per minute) that the HR sensor somehow locks onto cadence instead. Here’s a recent example:

hr1

At about 28 minutes I walked for a moment, and immediately afterwards the HR measurement shot up by 20 bpm. It stayed at this artificially elevated level for 4 minutes, until I walked again. Here’s another graph from the same run, showing HR vs cadence. Garmin normally displays the two on different vertical scales, so I’ve used Photoshop to align the cadence and HR scales for a zoomed-in graph:

hr3

From 28:20 to 31:40 it’s obvious that the HR number reported by the FR235’s optical sensor is actually my cadence, not my HR. It didn’t correct itself until I walked at 32:00 (orange dots way down near 100). This happens fairly often, and the effect can last for many minutes. Grrrr.

 

Failure to Recognize Elevated Heart Rate

The final problem I’ve observed with the FR235 optical HR sensor is more subtle. Sometimes I’ll increase my effort level significantly, such as for some tempo-pace miles in the middle of an easy run, but the FR235 doesn’t seem to notice that my HR has increased. Here’s an example from today:

hr4

Initially I was plodding along at a 9:15/mile pace, with a HR around 145. At 27 minutes, I increased the pace to 7:55/mile, and held it there for the next four miles. This was on a pancake-flat bike path, and the pace was nice and even, so my HR should have been roughly constant. Yet the FR235 showed an initial HR jump to the mid 150s, followed by a return to the 145 level, where it remained for a long time. At about 50 minutes it showed an abrupt HR jump of 20 bpm up to 165, even though my pace and effort hadn’t changed. The HR numbers then remained around 165 until I slowed back to an easy pace, at 58 minutes.

Based on knowledge of my HR zones from past runs, the numbers around 165 are likely correct, and the measurements from the 23 minutes before that are bogus. 23 consecutive minutes of faulty HR data, during an even-paced, even-effort run on level ground. You could fit an entire 5K race into that window. Grrrr.

 

Improvements and Conclusions

Maybe I’m wearing the FR235 wrong, or using it incorrectly, leading to poor HR measurements? In the interest of science, I shaved my wrist in the area under the watch, to ensure the sensor had a clear patch of skin for measurement. Per the instructions, I wear the watch slightly further up my arm than I normally would, so it’s well away from my wrist bone and can sit flat against my skin. The strap is adjusted pretty tightly, to guarantee ambient light won’t sneak in under the watch. It’s tight enough that the watch-shaped dent in my skin is still visible 30 minutes after the watch is removed. Any tighter would be unacceptably uncomfortable.

Some reviewers recommend trying the watch on your other arm, or turning it around so it’s on the inside of your wrist. I’ve not tried these solutions, since they defeat the easy and convenient appeal of a wrist-based HR sensor. Who wants to wear their watch on the inside of their wrist? I would sooner just wear a conventional HR strap.

Fortunately it’s possible to do exactly that. The FR235 can be used with an external Garmin HR strap, like the strap from a FR230 or FR220. If present, the FR235 will use the HR data from the chest strap instead of its own optical HR sensor. This makes it possible to use a chest strap for important workouts and races where accurate HR data is crucial, while getting sort-of-accurate HR data from the wrist sensor on other runs. It’s not great, but it’s still better than wearing a chest strap every day, or not getting any HR data at all for those other runs.

Outside of running, the FR235 also measures all-day heart rate. I’ve found this data to be surprisingly interesting and useful, especially the measurements of resting heart rate. By watching how RHR changes from day to day, I can identify periods where I might be overworked and need to take an easy day to avoid overtraining. I’d never get that sort of data from a chest strap.

For now I’m living with the iffy HR data from the FR235 on most runs, even though I know it’s sometimes off by 20 or more beats per minute. For workouts where I care about getting more accurate HR data, I wear the chest strap. Meanwhile, I’m looking forward to what sensor improvements Garmin and others may bring in the future.

2016 Bizz Johnson Trail Marathon Race Report

Combine the beauty of a trail race with the speed of a road marathon, and you get Coastal Trail Runs’ Bizz Johnson Trail Marathon: 26.2 miles of trails that are USATF certified and a Boston qualifier. The course is a rails-to-trails path with very gentle grades that a locomotive could handle, meandering through pine forests along a picturesque river. This little gem of a race happens each October in the town of Susanville, in the remote lava-sculpted lands of far north-east California, not far from Lassen Volcanic National Park.

Several friends from the SF Peninsula Trail Runners group were running Bizz Johnson, and I decided to join the fun with a comparatively last-minute signup. Coming off a base of 10 lazy miles per week, I only had 9 weeks of real marathon training before the race – about half the preparation I normally put in for a marathon (cue the ominous warning music). Despite the abbreviated training schedule, I still managed to fit two 20 milers and another fast 16 miler, peaking with a couple of 45 mile weeks. Based on those training runs, I estimated I was in shape for about a 3:45 marathon time if run at sea level on a flat course.

Three of us made the 6-hour drive up to Susanville on Saturday morning, meeting the other three there at the pre-race packet pickup. I learned there were 99 runners registered for the marathon and 26 in the 50K, with another few hundred registered for the 10K and two different half marathons. Susanville proved to be larger and more interesting than I’d expected, and a nice little jumping off spot for outdoor adventures in this remote part of the eastern Sierras. We checked in to the Super 8 motel, grabbed an early dinner at the Pioneer Saloon, and were in bed before 9PM.

Sunday morning we awoke early and drove to the Susanville train depot, where we caught the shuttle bus to the marathon start 20 miles west of town. Our bus driver made several wrong turns and we only arrived about three minutes before the 9:00 AM start, so there was no time for any lengthy pre-race preparations. The sun sparkled in a cloudless blue sky with temperatures in the 40s as the race director gave some brief final instructions. Then without further fanfare, we were off!

Bizz Johnson Start

The big question was how to pace myself, and what kind of time to aim for. The course elevation profile showed a 1200 ft drop from mile 6 to the finish line, growing steeper after mile 12. With a profile like that, maybe it would be a very fast course and I could beat my 3:45 finish time estimate. The profile also appeared to virtually guarantee a negative split, with the second half of the marathon run in less time than the first. This made it perfect for the Strava Back Half Challenge, in which runners could win a free pair of New Balance shoes by running a negative split in a USATF certified marathon during fall 2016.

But the big elevation drop was only half the story. The first six miles of the course were actually uphill, and miles 6-12 were almost flat. The 5100 ft average altitude was a major factor too. While it wasn’t so high that you could really notice a difference while standing around chatting, the altitude definitely had a negative impact on race pace. After consulting a few reference sources, I decided that the course profile would likely give a 3-4 minute benefit, but the altitude would give a 10-15 minute penalty. So the whole race might be about 10 minutes slower than a flat sea-level marathon. I set my goal for a 3:50 to 3:55 finish time, and hoped for the best.

Bizz Johnson elevation profile

From the very start I was about 15 seconds/mile slower than I’d expected, even accounting for the altitude. Either the altitude had a bigger impact than I’d thought it would, or I just wasn’t as fit as I thought I was, but I listened to my body and simply hoped I could make up time later. The course began with a short out and back section on a fire road before officially turning onto the Bizz Johnson Trail. There was some annoying loose gravel in the early miles, but most of the trail was great for running, with about 50% in the shade and a light breeze. The race ticked along with small but cheerful aid stations every three miles. I fell in with other runners whenever I could, and tried to keep the pace conservative. I passed a few people and just rolled along, waiting for the downhill.

After mile 12 it became clear that a 1.5% grade barely counts as downhill for tired legs. Yes, the pace improved by 10 or 20 seconds per mile, but visually you could hardly discern the grade. I talked with one disgruntled runner who said it was all bullshit, and claimed you could see the course was trending uphill just by looking at it. Up or down, I kept a fairly consistent pace but still behind my 3:50 – 3:55 goal. My first half split was 2:02:13, so I needed to be faster than that for the second half to satisfy the Strava Challenge.

Bizz Johnson Trail

I managed to pick up the pace a little for miles 14-18, and for a while I thought sub-4:00 might still be possible. I ran in a loose group of four runners, which was pretty good considering the small field and how far we were into the race. At mile 20 we reached the only real hills on the course: a short descent down to the river level, under a freeway, then back up the slope on the other side. By this point I was starting to strain, but was still mostly holding together. I passed the other runners in our little group shortly after the 20 mile aid station, and after that I was completely alone until the finish. The good news was this was the most beautiful part of the course, right down by the river. The bad news was it was the finish of a marathon.

Ah, the final miles of a marathon… are they ever not miserable? It’s hard to avoid those thoughts of “this is stupid, why am I doing it?” I was hanging on OK through 21-22 miles, but couldn’t muster the brainpower to calculate whether a sub-4:00 were still possible. My breathing grew louder, and a snake slithered away from my approach. Then someone loaded a refrigerator onto my back, and it became obvious that sub-4:00 was out of the question. A pace that had felt manageable two miles earlier suddenly required a major effort to maintain. Two dark and spooky railroad tunnels in the final miles were a nice change, but it was so dark inside the tunnels that I was forced to slow my pace further to avoid tripping on unseen rocks.

railroad tunnels!

The last two miles were tough. The temperature had climbed into the upper 70s, the shade was mostly gone, and my pace was fading further and further. I knew sub-4:00 was gone, but I really wanted to make a negative split and complete the Strava Back Half Challenge. If I could hold on to the pace for two more miles I’d have it, but if I continued to fade even a little more, it would slip out of reach.

I pumped my arms furiously while my heart jackhammered, but the pace kept creeping slower. It was going to be close. My brain was too fuzzy to do accurate math, but I decided that if I still had at least 3 minutes left at the 26 mile marker, I could still make the negative split. But when I passed the marker I saw there were only 2-something minutes left – no!!! I swore out loud and then absolutely killed myself going as hard as I could for the final 0.22, which wasn’t very fast, but felt like running through quicksand. I hit the finish line at 4:03:36, for a 50-second negative split. Mission accomplished.

After the finish I flopped down on the ground and lay there gasping for about 10 minutes. My hands and face were all numb, which was a little scary, as nothing like that had ever happened to me before. When I recovered, I learned that I’d won 2nd place in my age group, which seemed fantastic until the next day when I learned there were only 2 people in my age group. Oh well, I’ll take it anyway!

CTR put on a nice finish line barbecue, and I enjoyed the company of other sweaty and exhausted runners while waiting for the rest of the Peninsula Trail Runners to finish. Everyone did great! Among the six of us, we set four PRs and earned three medals. After finishing we soaked our tired and filthy feet in the Susan river before taking another shuttle bus back to town. Thanks Coastal! It was a great race.

The race data on Strava: https://www.strava.com/activities/739930200

Mt. Whitney and the Brazen Dirty Dozen

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In the past week I’ve faced two of my hardest physical challenges ever: the Brazen Dirty Dozen endurance race July 12, followed nine days later by a single day climb up and down Mt. Whitney, the highest summit in the continental United States. Why attempt two such difficult endurance tests on back-to-back weekends? It was sheer stupidity on my part, but I survived, and may even be stronger as a result.

 

The Brazen Dirty Dozen

First up was Brazen Racing’s “Dirty Dozen” and half dozen trail races: run as far as you can in 6 hours (half dozen) or 12 hours (dirty dozen). Unlike typical races, in this format everyone runs for the same amount of time, and the winner is the person who covers the most distance. What kind of sick person would even attempt a race like that? Apparently, someone like me. Having never before run further than 26 miles in 4 hours, I decided the 12 hour, full dozen event would be suicide, and opted for the half dozen 6 hour race instead.

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The Dirty Dozen race was on mostly level trails at the Pinole Seashore, on the San Francisco Bay north of Oakland. The main course was a 3.3 mile loop with about 100 ft of elevation gain and loss. During the last hour of the event, Brazen also opened a second 0.6 mile loop. Only complete loops counted towards your distance total, with no partial credit, so the goal was to arrange yourself to finish your last loop just before the clock reached 6:00:00.

Prior to the race I’d been having a lot of trouble with both ankles and one knee, due to several unrelated running and hiking accidents over the previous weeks. Until a few days before the race, I wasn’t sure I was going to be able to do it at all, but the injuries seemed to heal just in the nick of time.

We started off at 7:00 am on a cool, cloudy morning with a light breeze. Unsure how to pace myself or what distance I should expect to run, I decided simply to take it very easy, and make my goal be to keep moving for six hours, whatever the pace. If I felt like I needed to slow down or walk, fine, as long as I kept moving. I settled into a pace around 9:00 to 9:30 per mile, which was a very easy effort level for me, equivalent to an easy jog or recovery run. I chatted a bit with the other runners, learning who was an ultra running veteran, and who was a first timer like me. I was a bit in awe of the people running in the 12 hour category, and took their advice to keep the pace slow and relaxed.

The laps went on and on. It remained cool and cloudy for the first four hours, though it did get warmer towards the end of the race. I never really had a problem with the knee or ankle. There were some random knee pains briefly about half-way through, but they went away and never came back. So I just kept running. With the loop format, after a while everyone was on a different lap, and I didn’t know where I stood in the overall field. When I passed someone, I didn’t know if I was moving ahead of them, or lapping them, or if they were already a lap up on me. But it didn’t seem like many people were running as fast as I was, and I was rarely passed, so I guessed I was doing pretty well.

Unlike virtually every other race I’ve ever done, I ate and drank a ton! Normally for a marathon I would eat some Gu or Shot Bloks, and that’s about it. But in this race I ate boiled potatoes, peanut butter and jelly sandwiches, potato chips, pretzels, soup… everything. I might have taken in 1000 calories or more. It just seemed like the thing to do, and the aid stations were well-stocked with a smorgasbord of food.

I kept running, and running, and running. Except for a few seconds to grab some snacks at each aid station, I ran the entire way from start to finish. I kept up a pretty steady 9:10/mile pace for the first four hours, then I faded a little to a 10:00 or 11:00/mile pace for the last two hours. I was getting exhausted. Mentally I think I was prepared to run a marathon distance, but no more. So when I crossed the 26.2 mile point and realized I still had lots more running to do, it was like getting a kick in the face. During the last big loop, I was kind of a wreck, talking to myself out loud, and just trying hold everything together for a few minutes more. As the clock ticked down, I had time to squeeze in one lap of the 0.6 mile loop too, finishing up in 5:56:52, staggering over the finish line in tears.

I had run 37.33 miles. Jesus God, that is far – almost 50% farther than I’d ever run before. Crazy far, like the distance between two cities. I avoided injuries, and I didn’t have any joint pain or blisters, but physically I was a wreck. I wobbled drunkenly around the finish area, wanting desperately to lie down, but afraid that my muscles would spasm and lock up if I stopped moving. So I stayed on my feet, and stuffed my face with ice cream, bagels, and Gatorade.

The results were posted about half an hour after the finish. I thought I’d done OK. On a good day, I can usually finish in the top 10% or 20% of the overall field at most races. I checked the results, and the winner had gone 41 miles. My 37.33 miles was good for 3rd place overall out of 182 people, and I won the M40-44 age group! Holy cow!

I missed a couple of splits near the end of the race, but it went down roughly like this:

Long Loops (3.33 miles)
1: 30:37
2: 29:45
3: 30:42
4: 30:32
5: 30:10
6: 30:53
7: 30:51
8: 31:39
9: 34:13
10: ~35:23
11: ~35:22

Short Loops (0.65 miles)
1: ~5:54

My marathon time was 4:02, and my 50K time was 4:51.

Overall, the Dirty (Half) Dozen was an interesting and exciting event. But I think I’ve been cured of any desire to do another ultra. Maybe, maybe I could do a 50K, but that’s about it. After finishing 26.2 miles at the Dirty Dozen, I just really didn’t want to be there anymore. TOO LONG!

 

Mt. Whitney in a Day

Nine days later, I found myself at Whitney Portal in the Sierra Nevada mountains, about to begin a single day hike up and down Mt. Whitney. At 14,508 feet, Whitney is the tallest mountain in the continental United States. The trail from Whitney Portal is 22 miles round trip over rocky terrain, with 6200 ft of elevation gain, and the whole distance at high altitude where oxygen is scarce. Smart people make the trip over several days, camping along the way. Only idiots like me attempt to do the whole thing as one giant day hike.

I’d been wanting to climb Whitney for a few years, but it wasn’t until this May that I happened to check the park service web site, and found there were still day use permits available for July. I grabbed two permits for July 21, convinced my friend Jeff to join me, and started making plans.

I’m in pretty darn good physical shape. I run 40+ hilly miles per week, and I do marathons and ultras. I’ve climbed three previous California “fourteeners”, and a couple years ago I hiked most of the John Muir Trail from Yosemite to King’s Canyon. So I assumed the warnings I’d read about how demanding the Whitney day hike is didn’t apply to me, and we’d be up and down the mountain far faster than average. Ha! The mountain kicked my ass.

Our acclimatization began on Saturday with a drive up to Yosemite and an easy hike around Tuolumne Meadows (8600), then spending the night at Mammoth Lakes (7800). Sunday we picked up our permits in Lone Pine, then did a day hike from Horseshoe Meadows up to Trail Pass and Mulkey Pass (10500). We spent Sunday night at Whitney Portal (8300) before beginning our hike early on Monday morning.

We awoke at 2:00 am, wondered what the hell we were getting into, then were on the trail at 2:35. We checked the scale at the trailhead, and my pack weighed 15 pounds including 2L of water. I carried:

  • ULA Catalyst pack
  • 2L water
  • katadyn water filter
  • two headlamps
  • 2500 calories of trail mix, energy bars, fruit, etc.
  • lots of extra warm clothes, most of which I ended up wearing later
  • first aid kit
  • emergency bivy sack
  • compass
  • sunscreen
  • camera
  • maps and timetable
  • WAG bag

We started off well, and I really enjoyed hiking in the dark. Our headlamps gave plenty of light to see what we were walking on, but not enough to see much around us, so it was like hiking through a dark tunnel. Occasionally we stopped and turned off the headlamps to gaze at the stars, which were tremendous. Around 4:45 am, somewhere past Mirror Lake, the sky began to glow a dull orange. Watching the sunrise and the alpenglow was incredible. I loved every minute!

Around 3 hours into the hike, Jeff began to lag. Up to that point we’d been averaging about 2 miles per hour, joking and singing as we went, but he quickly grew quiet and said he was feeling tired. We continued on, but more slowly than before. Our strategy the whole way up was to hike at a slow and easy pace, but keep going without any breaks except the occasional stop to remove a layer of clothing or get something out of the backpack. In retrospect, maybe we would have done better to take a 10 minute break every hour or so. After six hours of hiking we finally reached Trail Crest, the point at 13,800 ft where the trail crosses the ridge line onto the back side of the mountain. Jeff was not having a very good time. He was determined to keep going though, and said he would “dig deep” to make it to the summit.

My secondary goal was to climb Mt. Muir, a 14,019 foot peak only a short distance off the Mt. Whitney trail. From what I’d read, it was a fairly easy detour from the main trail, and only a few hundred feet up to Muir’s summit, involving a small amount of class 3 scrambling at the final summit block. It wasn’t clear to me exactly where Mt. Muir was or where to detour from the main trail, though. All the rocky outcroppings looked the same. Eventually I located it, and after some discussion, we decided Jeff would continue slowly on towards Whitney summit while I climbed up Muir, then returned to the trail and caught up to him from behind. I followed a faint use trail up the pile of rocks towards Muir’s summit block. It wasn’t great. There was nothing super difficult about it, but I was moving very slowly, climbing with hands and feet, and searching out the best direction to continue up after every few steps. After ten minutes I made it about half way up to the base of the summit block, then stopped and stared up. I looked long and hard at the summit block, and decided no, not today. If I’d been with someone more experienced who could have helped guide me up, I think I would have been fine, but I didn’t feel like pushing my luck while hiking there alone. So I chickened out and climbed back down to the trail, which was a lot tougher than climbing up had been.

This is as close as I got to the top of Muir. Somehow it looks a lot closer in the photo than it did in person.

I hurried to catch up with Jeff, reaching him about 15 minutes later. He was still moving forward slowly, with a look of grim determination on his face. This section along the ridge was absolutely incredible, with strange rock fins and pinnacles poking up everywhere, and dramatic drop-offs to the right through the “windows” between sharp needles of rock. I felt like we were really mountaineering now. We kept going, reaching a point about half a mile from the summit before Jeff stopped and said “I’m not going to make it”. I was about to reply with some motivational gambit, when he turned and vomited on the trail, retching over and over until there was nothing left in his stomach. Then he sat, feeling slightly better after the vomit. Groups of people appeared suddenly coming from both directions, seemingly unconcerned about stepping in the pile of vomit in the middle of the trail.

Years ago while climbing Mt. Shasta with Jeff, I got sick around 12500 ft, and he abandoned his summit attempt to hike back down with me. I was prepared to do the same for him there, but after 10 minutes of rest he felt well enough that he wanted to continue. We knew we had less than 30 minutes of hiking left to reach the summit, so off we went. Before long the roof of the Smithsonian hut crept into view, and then we were there. Hallelujah! I ran around shouting and fist pumping while Jeff collapsed on a rock, exhausted. Our total time from trailhead to the summit was 8:15.

The weather was great at the summit, with about two dozen people milling around in the sun. A layer of puffy clouds hung below the summit. Then I did something I’ve never dared to before: crept up to the very edge of the east face, sat on the last rock, and dangled my legs over the 3000 ft drop straight down. I was terrified and my heart was racing, but it made for a cool photo! 🙂

After about 25 minutes, we started back down. Jeff ate a little, and began feeling slightly better. As we descended, our conditions seemed to reverse. He began to perk up, while I started feeling crappy. By the time we got back to Trail Crest, he was in good shape, but my head was pounding and I was exhausted.

The rest of the miles seemed to last forever. The whole way down stretched out interminably, and I kept thinking we were farther along than we really were. I lost track of the number of times I said “I don’t even remember hiking up this.” Any sense of enjoyment in the hike was completely gone, and I was fully in zombie survival mode with no thought other than to reach the bottom. I think the altitude was certainly a factor, but the main problem was just exhaustion. The trail just went on and on, forever. It took us 6:55 to make it down, which wasn’t much faster than our time on the way up. Including time spent at the summit, the whole hike took 15:10 round trip. When we reached Whitney Portal at 6:15 pm, I was completely wrecked. I was almost in tears. But after some food and an hour’s rest, I bounced back and was feeling half-way normal again. Wow.

It was an awesome hike, and I especially enjoyed traveling in the dark, watching the sunrise from the trail, and traversing the ridge near the summit. But I think you have to be an idiot to want to do this as a day hike from Whitney Portal. Either that, or you need to be in outstanding physical shape and practically immune to the effects of altitude. With my prior conditioning and endurance running, and two days spent acclimatizing, I thought I could handle the Whitney day hike without too much trouble. I was wrong, and the last few hours of descent were completely miserable. If I ever climb Whitney again, it’ll definitely be as a two or even three day camping trip, and none of this day hike craziness. My hat’s off to those who can do Whitney in a day and return in one piece. That is one hell of a tough hike!

Garmin Soft Strap Heart Rate Monitor Failures

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Heart rate monitors are temperamental things. In the past few months I’ve gone through two Garmin Forerunner 220’s, and in both cases the bundled soft strap HRM began to fail in the same peculiar way after about a month (roughly 24 uses). It’s driving me bonkers! Both straps worked great for the first month, but after that I began to see weird behavior on runs lasting more than an hour. Somewhere during the second hour, the pulse rate would start decaying steadily down, regardless of how hard I was exercising. Sometimes it would jump up again to a normal-looking value, but more often it would continue decaying downward from around 150 all the way to the 40’s, and stay there until the end of my workout. It rendered the HRM nearly useless for long runs.

An hour-long total decay, with eventual recovery:

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Partial decay at the end of a marathon, with some earlier gaps:

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Total and permanent decay at the end of a workout:

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This pattern of failure seems different from the types of HRM trouble I’m more familiar with, which involves bogus (usually too high rather than too low) pulse readings at the beginning of a workout. That problem is normally caused by poor electrical conductivity between the strap and the skin, and can be solved by wiping on some spit or electrode gel, or just waiting until the skin gets sweaty. DC Rainmaker has a good explanation of this and other common HRM problems. But I don’t think that’s the problem here, and I always use electrode gel anyway.

What on earth might cause a problem like this, that only strikes after an hour or more into a long run, and only after a month of use for the heart rate monitor? When the first HRM started malfunctioning a couple of months ago, I tried cleaning the strap, tightening the strap, replacing the battery, and updating the firmware. Nothing worked, and I eventually exchanged the watch and HRM for a replacement. Now just over a month later, the replacement has started to do the same thing. Ack!

If I had to guess, I’d say it’s somehow related to the accumulation of salt from sweat, which builds up over time and shorts out the conductive thread woven into the strap. That would be consistent with a problem that doesn’t appear for a month (it takes a while for enough salt to accumulate), nor until running more than an hour (it takes a while for the strap to become saturated with sweat). The Garmin soft strap does say right on it that it should be machine washed after every seven uses, which I admit I’ve never done. But washing it once this problem appears don’t seem to fix it.

Some Amazon reviewers reached a similar conclusion, though their symptoms sound different from mine. Some found partial success in washing or soaking the strap, and others by cleaning the snap contacts on the transmitter with a deoxidizing cleaner. If I can’t find a reliable answer soon, I’ll probably have to throw the Garmin HRM in the trash and look for a compatible HRM from Polar or another vendor that doesn’t suffer from this strange decay issue. Sad.

 

Update July 13:

I’ve concluded the Garmin soft strap HR monitor is flawed by design, and I can’t recommend it to anyone. After lots more experimentation, I confirmed the problem is at least partly due to sweat and salt build-up in the strap fabric. Unfortunately, washing the strap doesn’t really fix the problem. In my tests, hand washing with soap in a sink of warm water didn’t help at all, and machine washing with other laundry (per Garmin’s instructions) only partially helped. After washing, the problem returned again within a matter of days, if not sooner.

The final straw was a 6-hour endurance race I competed in yesterday. The day before the event, I machine washed the strap and air dried it while lying flat, so it would be ready to go for the race. Despite the washing, the heart rate data started flaking out after the first hour. It recovered twice, but eventually it went completely nuts and gave me totally wrong HR data for the last 2.5 hours of the race. I was not happy.

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Maybe the sweat and salt become so embedded in the strap’s fabric that even a machine washing can’t completely remove them? Or maybe the salt permanently damages the conductive threads in the fabric? Perhaps it’s some kind of mechanical failure unrelated to sweat and salt.

One thing’s for sure: after going through two of these soft straps, both of which worked great for the first month after purchase, I’m confident the problem has nothing to do with how I’m wearing the strap, or moisture on my skin, or the battery. It’s some kind of cumulative failure that’s inherent in the soft strap HRM design. Washing may provide temporary relief, but eventually the HRM will become a useless piece of junk. Stick with the tried-and-true hard strap design – the Garmin soft strap just doesn’t work.

Big Basin Skyline to the Sea Trail Marathon

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The Skyline to the Sea trail is a gem. Just a few miles from busy Silicon Valley, this trail traverses most of the Santa Cruz Mountain range, 26 miles from the ridge at Saratoga Gap through foggy redwood canyons to the beach at the Pacific Ocean. I’ve hiked it a couple of times as a multi-day backpacking trip, and always wanted to try running it, but the timing was never right or the races were sold out. Then in January I saw Coastal Trail Runs had their Big Basin Skyline to the Sea Trail Marathon scheduled for June, and they still had space available. Yes! I was in.

Beginning in January, I started on a training program to whip my out-of-shape butt back into marathon form. It all went surprisingly well, and I ran several shorter races along the way, including two half marathons, to get myself ready for Skyline to the Sea on June 8. When race weekend finally arrived, I felt fit, healthy, rested, and ready to go.

We arrived at Saratoga Gap about 8:15 for the 9:00 start. Panic struck as I realized I’d forgotten my water belt! Nooooooooo! I took a 20-ounce waist-mounted water bottle on all my long training runs, and had planned to use it on race day during the long dry stretches between aid stations. Instead, I had to beg a used 16 ounce screw-cap disposable bottle from another runner, and carry it in my hands the whole way. I wasn’t happy with that solution, but there wasn’t any alternative.

Coastal Trail Runs organized the race as a marathon concurrently with a 50K, with an extra 5 mile loop for the 50K course. Since everyone was running at least a marathon, it was an athletic crowd. About 300 people squeezed onto the narrow trail at the start, with 175 in the 50K and 125 in the marathon.

Right from the first mile it was HOT! The morning weather in these mountains is normally cool and breezy even in summer, but this day was the hottest day for months, with forecast highs in the mid to high 90’s. The weather data from nearby towns shows it was about 83 at the start of the race, climbing to about 89 in the first 90 minutes. I was uncomfortably warm and beginning to cook. The trail trended downward, but with lots of small ups and downs and twists that demanded concentration. I kept willing myself to slow down and take it easy, but my body started to overheat.

Drinking from the screw-cap disposable bottle was more difficult than I’d expected. Just unscrewing the cap without dropping it while running was tricky, and then the water sloshed and spilled all over the place. I couldn’t squirt it into my mouth like with my normal bottle, and had to stop and walk for a few seconds to drink it down without spilling everywhere. Whenever I did this, two or three people passed me.

I reached the first aid station at Waterman Gap (6.5 miles) at 55 minutes, having averaged about an 8:30 mile pace. The heat had taken its toll, and I felt baked. I spent two or three minutes just lounging at the the aid station, which is something I’ve never done before in any previous marathon. I refilled my bottle, drank three more cups, ate some Shot Bloks, and just caught my breath. I overheard one of the volunteers say something about running low on water, which sounded bad considering there were many more runners behind me yet to come through. Whether the shortage was due to the heat or some logistical error, I don’t know, but it was a bad day to run out of water.

Leaving the aid station, I went into survival mode and just ran easy. I was pretty sure I was headed for a very bad day and lots of walking, so I forgot about racing for a while and just tried to keep moving forward. But a funny thing happened: I started passing people. Maybe they felt even more cooked than I did? The course climbed for a few miles, and many people walked the uphills, but I jogged up them slowly but steadily. Somewhere around mile 10 or so, I started to feel better and caught a second wind. I kept passing people. Many other runners were flagging already.

My GPS watch tracks distance and pace during my runs, but the endless switchbacks and poor reception in the canyons rendered it nearly useless for this race. I didn’t know how far I’d come, or how fast I was moving. And even if I’d known my current pace, how would I have known what pace I should be running? Uphill, downhill, scramble up a rock, come to a complete stop and climb over a fallen tree: it was impossible to keep a consistent speed.

After 1:46 I reached the second aid station at China Grade (11.2 miles), my average pace having now fallen to about 9:30/mile thanks to the climbing. My family was there, and it was all smiles and high fives for a few minutes while I refilled the bottle and wolfed down some food. Water, water, give me water! Once again I stopped at the aid station for several minutes, which seemed like an eternity, but I needed it.

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The trail after China Grade was probably the most technically challenging section of the course. We exited the deep shade of the forest and hit a stretch of tilted rock slabs toasting in the sun. Part of it involved running on a side slope on slippery rock, up and down little steps, and through a few bits that were more like climbing than running. Despite my slow pace, I continued to pass other runners. Following this we returned to the forest shade and plunged down a very steep downhill that was like a minefield of roots and rocks and sharp turns. I must have tripped and stumbled at least a dozen times, but managed to catch myself before falling.

Somewhere in the forest around mile 13, while I was trucking down one of these steep rutted sections of trail, my foot landed wrong and I came over my ankle sideways with all my weight on it. There was a sickening CRUNCH and I screamed. But I had so much downhill momentum that I couldn’t stop, and had to hop down the trail on one foot. When I finally stopped, I was sure I’d torn or broken something, and would need an aid crew to help evacuate me to the nearest road. The race was over. But after a minute or two of walking, the initial pain subsided, and the ankle actually didn’t feel too bad. I moved into an easy jog, then within a half mile I’d resumed my former pace. I definitely dodged a bullet there, as I could easily have broken the ankle.

At 2:19 I reached the Gazos Creek Rd aid station at Big Basin Park HQ (mile 15.8). My average pace had improved to about 8:45/mile, so I must have been moving pretty fast considering I walked for several minutes after the ankle injury. My family was there, and I stopped again to exchange high-fives, rehydrate and refuel. I also picked up a second water bottle, knowing that it was a long way to the next aid station and my single 16 ounce bottle wouldn’t be enough. Carrying a water bottle in each hand is like lifting a 1-pound weight with each step. It’s small, but over time the effort adds up, and I could feel an unfamiliar ache in my biceps and shoulders.

The last big climb on the course was just after the aid station, about 500 feet up to the top of the ridge separating Big Basin from the Waddell Creek drainage. I chugged up the hill at my slow and steady pace. By this point the field had thinned out, and I couldn’t see any other runners ahead or behind, but there were lots of hikers on the trail heading to the popular Berry Creek Falls viewpoint. Nearly everyone was good about yielding the trail as I came through, but occasionally it was so narrow that they couldn’t, or I came up behind a hiker so suddenly that they were startled. I wasn’t really moving very fast, though, so pausing for a few moments to squeeze past a hiker didn’t bother me.

Across the ridge, I descended into majestic old-growth redwood forest, nestled into narrow canyons splashed with ferns and moss, with quiet waterfalls whispering at the sides. I was 18 miles into a marathon and hurting, but I grinned ear to ear at the beauty of it all. I can’t imagine a more lovely setting, and at that moment I was grateful to be there, healthy and alive and in the middle of it all. The canyons were filled with cool coastal air, and the temperature dropped from the 80’s into the 70’s or 60’s. Sweet relief!

I think I got passed once here, but also passed one or two people. My brain had floated away somewhere else, and I wasn’t really paying attention or even forming coherent thoughts. The trail went on and on. I passed Berry Creek Falls, a straight drop 65 feet down that’s tucked in between the redwoods and ferns. I crossed a creek several times, and went up and down again and again on little hills by the creek. Most of these were small, but a few were more challenging and one was a very steep uphill – the only place on the course where I walked outside of water stops. I ate more Shot Bloks, stuffed my mouth with raisins and almonds, and kept moving. After the falls, I was completely alone.

Somewhere around mile 21, I finally caught up to two runners. One was tired and walking, but the other still had some gas left. I passed him, then he sped up and passed me back. We’d spoken earlier on the course, and he told me this was not only his first marathon, it was his first race at any distance! He sure picked a tough place to start. We dueled it out for a short while, but eventually I was able to pass him for good. As it turned out, he was the last runner I saw before the finish line.

I bumped along a while longer, not knowing the distance or my pace. I knew I must be in the final 5 miles or so, and it was time to muster whatever energy reserves I had left, so I tried to dial in a hard but manageable level of effort. But with nobody in sight ahead or behind, it was tough to convince myself that an extra 20 seconds or even a minute were really going to matter. I managed something like a tempo run effort, but it wasn’t all-out 100%.

I was now on a mostly flat stretch of fire road in a broadening valley, approaching the coast. My lonely meditation was finally broken by a hiker walking up the road. He cheered me on, and told me I was in 7th place. 7th place! I don’t think I’ve ever been that high in the overall standings before, and the news really lifted my spirits. But it also ignited a fear of being caught from behind, so I turned up the effort level higher.

I reached the Twin Redwoods aid station (24.5 miles) at 3:58 – more than an hour and a half between aid stations! That’s a long, lonely stretch of trail. The volunteers confirmed I was currently 7th, and asked me how I was feeling. I felt surprisingly OK – I was even smiling! I quickly gulped a few cups of water, but didn’t bother to refill my bottle since I had less than two miles left to the finish.

Immediately after the aid station was the final climb on the course. It didn’t look like much on the elevation chart, but coming where it did in the last two miles, it was mean. I pushed up the hill with the best effort I could manage, paranoid that another runner was going to chase me down from behind through this final stretch. The hill wasn’t steep, but it seemed endless. After about a mile of hot and dusty chugging, I came around a bend and was rewarded with a breathtaking vista of the coast plain, the beach, and the ocean waves foaming in the distance. There was still a bit more climbing before the trail finally turned downhill. About 200 yards out, my daughter Alice met me on the trail, and we ran hand-in-hand down to the finish.

Woohoo! I was covered in dirt, bugs, and salt, and my muscles ached, but I felt great! My finish time was 4:14:33. It turned out that one of the runners ahead of me was actually in the 50K (and broke the course record), so I finished 6th place overall in the marathon and 3rd in my division. That was well ahead of my expectations going into the race, and I was thrilled. And that runner chasing me down in the final miles? There was no one. The next person finished several minutes behind.

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I relaxed at the finish line for about an hour, chatting with the other runners, cheering as more people finished, and refueling with pretzels and soup. It was a very friendly and relaxed atmosphere, so different from the road mega-marathons I’ve done in the past. The post-race high wore off a bit when I got home and saw that my ankle had swollen up like a grapefruit, but thankfully it didn’t hurt much. With a couple days of rest I’m optimistic that it’ll be ready to resume running again.

Overall I was pleased with the Costal Trail Runs experience. From end to end everything was well organized, and the people were all relaxed and friendly. I really enjoyed the atmosphere at the finish line. It was obvious the Coastal people had hosted these races often enough to have the details nailed. There was only one spot on the course where I thought a turn could have been better marked, but in 26 miles of twisty trails that’s a pretty good record. My only big concern is that I heard some of the aid stations ran out of water for the runners at the back of the pack. Coastal isn’t responsible for the weather, but that’s still a major gaffe and they should have the experience to budget extra water for very hot days.

Before the race, I analyzed the results from past years to an embarrassing degree of detail. I looked for people who’d finished Skyline to the Sea within a couple of months of a flat road marathon or half-marathon, and then attempted to find a formula for predicting finish times. My conclusion was that Skyline to the Sea was 45 minutes to an hour slower than what a runner could achieve on a flat road marathon course. From my race results earlier this spring I’d estimated I was in about 3:25 marathon shape, from which I projected a Skyline to the Sea finish time of 4:10 to 4:20. That proved to be right on the money.

Lessons learned? While this was my slowest marathon by the clock, it was my best ever finish by overall placement or percentile within the overall field. Everybody was cooked by the heat, but I seemed to tolerate it better than most. I’ve never before had the experience of methodically passing so many people in the second half of a marathon. I think I also hydrated more during this race than during any prior marathon, and I definitely took in more calories from food than I’ve ever attempted before. That probably helped stave off the wall in the final miles. This was also the first time I’ve incorporated strength training into my marathon preparation, and I think it helped.

In my past marathons I’ve always been a slave to the clock. If I needed a 7:38/mile average pace to reach my goal, and I had a 7:55 mile split somewhere, I’d freak out and push harder. That kind of clock watching just wasn’t possible in this race, so I went by perceived effort instead. I’m not sure if it worked better or worse, but it certainly felt less stressful, and the results were good. Next time out I’ll definitely try this strategy again.

If you ever have a chance to hike or run Skyline to Sea, grab it! It’s an absolutely gorgeous stretch of trail through nearly untouched wilderness, only an hour’s drive from San Jose and San Francisco. The descent through the redwood canyons to Berry Creek Falls is breathtaking, and deserves a spot on anyone’s bucket list. As a race it was very challenging: steep, twisty, rutted, rocky, and gnarled with huge roots – about as technical as trail races come. But the experience of sailing through fog, ferns, and fairy rings en route to 26 miles of tough accomplishment was worth every step.

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