#3 Walking Out On Your Own: When 2 Heart Rate Monitors Are Better Than One, Especially At Moderate Altitude (Spring 2012)

Caught Off-Guard
In 2011 we individually appreciated the motivational aspect of exercising with a heart rate monitor, sharing one inexpensive model between us to push up our tempo on foot and on the bikes. in the spring of 2012 we learned how powerful having 2 monitors--each wearing one--could be in short-circuiting a potentially dire situation. We were more than 2/3's the way down the 5000' face of the Grand Canyon making our return to the Rim above us and Bill said "I don't feel quite right."

Bright Angel Trail descends from the South Rim of the Grand Canyon.
This hike on the very steep Kaibab Trail was our second big effort in 3 days. Bill had been concerned both the day before and that morning that he wasn't recovering as quickly as usual from the previous hike down and then up the Bright Angel trail 2 days before. We'd steamed up that 3000' face in the heat, blasting by 183 other upward bound hikers and only being passed by 2. Only I was wearing a heart rate monitor that day and I estimated I'd been in the 150's beats/min for close to an hour on that trail. We recovered quickly once at the top, felt fine the rest of the day, and were nothing but pleased with our exhilarating training effort.

But the next day on our 'relative rest' day, we both noticed a slight lightheadedness with moderate exertion on the 7,000' elevation Rim and Bill felt nonspecifically "off." We loaded dinner with extra salt in case that was the missing ingredient and agreed to postpone the second big hike if Bill felt less than capable the following morning.

Carefully scrutiny of his sense of wellbeing in the morning signaled that we were on track for the planned Kaibab Trail hike. But a little lingering subconscious concern must have been behind Bill's last minute decision to strap-on a heart rate monitor. Pausing to let his heart rate settle, he noted that it was substantially higher than his usual very low rate. "Was it the altitude or was it a subtle sign of overtraining?" was the unanswered question. (Technically, overtraining is a cumulative effect after weeks or months of pushing beyond one's body's capacity to fully repair but overtraining was the best word we had for the concept we assumed we were confronting.)

Lounging for lunch at Panorama Point on the Kaibab Trail.
We enjoyed the stunning views of the Canyon from the Kaibab Trail as we made our descent from the South Rim towards the Colorado River and noted that the less convenient and steeper trail without water stations attracted far few visitors than the Bright Angel Trail we walked 2 days prior. And the lack of water and steepness also meant that it was basically a one way trail: people typically went down to the Colorado River on it and then on to the overnighting possibilities at Phantom Ranch but made their return up Bright Angel. Being same-day "out-and-backers," we realized we would make our return up Kaibab practically alone on the trail in the afternoon.

Bill's first bit of concern for himself bubbled up while picnicking at the stunning Panorama Point where the bright red sandstone top layer boldly juts out towards the Colorado. Typically we would have selected shade for lunch but the compelling view had us settling for the slightly cooling breeze while in the direct sun. But getting uncomfortable while eating and attributing it to the heat, Bill proposed we savor our dessert chocolate under the shade of a ledge about 10 minutes up the trail, which we did. We both appreciated the deeper sense of peacefulness from the scenery when our bodies were soothed by the welcome coolness and I took the time to put on my heart rate monitor for the first time that day.

Turning on my monitor instantly triggered the irresistible game: "108" answered with "118". But there was something wrong with the game: Bill's heart rate was the higher of the 2. Given the same activity or inactivity, my heart rate is always, always, at least 10 beats/minute higher than Bill's, if not more. Red flags went up for both of us with the mere uttering of our respective numbers: suddenly Bill's nagging concerns about being a bit "off" were significant and this was an absolutely terrible time to discover that he needed a day of rest instead of an afternoon of high exertion in the heat.

The good news was that we had plenty of food, water, and time to stroll up to the Rim rather than charge up as planned; the bad news was that we didn't know if he was close to being in a critical situation.

Putting It In Context
Over the last 15 years we'd had our share of experiences with short-term overtraining and the intertwined metabolic chaos. We'd had dozens of days on which we had dragged in for the night after a hard day on our bikes, catatonic and totally depleted. And on many of those days I'd had to sit on the floor of a shower stall in that evening because I was too pooped to stand to bathe. When training for those overseas cyclotouring adventures, I'd had a near-medical emergency during our first trip into Death Valley that had Bill watching me carefully for hours while I slowly recovered in our tiny tent. And there was my memorable failed attempt to ride over one more pass in the Dolomites after having done over 10 miles in vertical gain in a month. I mounted my loaded bike that morning in the Alps, pushed the pedals a revolution or 2 and told BIll: "I can't go today." On that day I recognized that I was deeply fatigued, not just a little stiff, and that there wasn't anything left for me to give. Overtraining (or whatever it is) wasn't new to us, but Bill's situation in the Grand Canyon was.

Over 250 people a year are evacuated from the Grand Canyon because of medical emergencies and Bill's situation was a perfect example of why: it is a down and then up event instead of an up and then down. Going downhill can be hard on the knees but it is less of a metabolic feat than going up, especially in the heat. And it's the additional stresses associated with going uphill that reveal an underlying problem. We were keenly aware of the issue beforehand and yet we were still getting caught in the trap.

A senior woman above our turn-around point on Kaibab was soon to be evacuated by helicopter from the Canyon because of
The injured woman wanted to ride a mule out of the Canyon but the choices were to walk or be airlifted.
misjudging her ability during her recovery from an orthopedic issue with her foot, perhaps a surgery. Thirty minutes after leaving her in the hands of a trail volunteer and before the chopper arrived, we spotted a man that we hoped would be getting into the chopper first.

That man's companion had just blown by us going downhill wearing a bulging frame pack and carrying another. "Something is very wrong" was my first though in seeing his cheerless expression and the second pack and then I realized we'd taken a photo of him and his buddy together at the top of the trail hours earlier with their camera. In a couple of more minutes we spotted his companion staggering down the trail with a decidedly spacey look to his face. I'd studied their faces and gear while Bill snapped their photo and his affect was totally changed from the morning. He of course answered "Fine" when we asked if he was OK. Bill alerted an approaching guide with a small group to the man's state and asked the guide to notify the volunteer waiting for the helicopter of the man's presumed precarious condition.

The 70-something man was clearly in serious metabolic chaos from the lesser stress of going downhill or was having an event from an underlying health condition or medication. Regardless of the cause, he vividly personified what Bill did not want to experience. But unlike him, we knew we had responded to an early warning of a brewing problem and we had a plan. And we had piles of experience in tweaking the variables in similar situations and hoped to not add another casualty to the growing list on Kaibab Trail that day.

Rallying Our Resources To Respond
Bill quickly settled upon using his heart rate monitor to more precisely track his level of stress on the hot, steep ascent. He arbitrarily set 140 beats/min as the top number he wanted to see as a way to pace himself. But he never got close to that. Very quickly he decided to keep his heart rate at a maximum of 10 beats higher than mine, which was at least 20 beats/min above his usual. Any time the spread between us was greater, we slowed down even more. A slow pace with rests every couple of minutes was the plan for him to coax his stressed body out of the canyon.

Watching his heart rate and repeatedly scanning his body for sensations of stress soon had him fiddling with elements other than tempo. He redoubled his efforts to stay hydrated. We stopped in every scant bit of shade to keep his core temperature down in the heat. And then he tried his back-up plan of salted prunes--you know--salted prunes.

Like when either of us has a cold or allergies, we always treat our symptoms with individual antidotes instead of cocktails so we can fine-tune the therapy and the side-effects: instead of buying an all-in-1 product, we take antihistamines, decongestants, and cough suppressors separately so we get precisely the right mix for the respiratory problem at the moment. Likewise our emergency food in our packs isn't the recommended salty snacks like chips and salted nuts, but nuts, chocolate, dried fruit, and salt. That way we can be more targeted in our therapy and better learn what the problem was by noting which remedy did the job.

On this occasion Bill settled for a mini-shotgun approach and poured a little salt on each wrinkled prune he ate. Was it the long rest in the shade, the salt, or the sugar that did the trick--he's not sure. But what he did notice was that it was much easier to keep his heart rate within 5 beats of mine whereas he had struggled to hold it at 10 beats above before the 'treatment.' That still meant he was likely 15 beats or more over what he'd normally run, but we were pleased that he had started reversing the downward spiral he was on while still hiking.

We carried on with this measured regime of constantly comparing heart rates and keeping Bill's in check with a slow pace and frequent rests for about 4 hours. He added another round of salted prunes to make sure he had enough--presumably salt--and then we dipped into other snacks when my dinner bell went off near the top. One of the problems of an 'event' slowing you down is that then you need more of everything because you are out longer than planned. We always carry extra food and water with us when cyclotouring because even a flat tire repair could start encroaching on the next meal and we used the same caution when hiking.

Bill made it to the top of the rim no worse-off than when he started feeling bad, which was both our goal and a huge accomplishment. Resting when we got back to the camper, eating dinner, and taking care not to get that chill that one is vulnerable to when metabolically messed-up paid-off and in about 2 hours he snapped out of his state of distress. He was lucky that the event didn't disrupt his night's sleep and was looking forward to 2 instead of 1 day's rest before his next big hike.

Lessons Learned
Heart Rate Monitoring Revisited
The only clear lesson that we learned during this near-disastrous hike up Kaibab Trail was the power of dual heart rate monitoring to detect and manage a physiology problem when the only practical way out of a situation is to carry-on (the helicopter ride out of Grand Canyon is $3,000 paid at the door of the chopper).

Enjoying the scenery wasn't part of the program during our slow ascent.
Heart rate monitoring is the gold standard for top athletes wanting to interrupt overtraining. Normally that is done by keeping a daily log of heart rates during specific activities and watching for the tell-tale increase in rate when the exact event is repeated. This approach doesn't work for us because we are always doing a different event under different conditions. Like on Bright Angel Trail, I was startled to see my beats/minute sustained in the 150's but I felt fine so I concluded that it was nothing more than a robust pace on a challenging trail on a hot day. But on Kaibab we learned where the magic was for us, which was in comparing heart rates with each other. We very consistently have a very predictable spread between our rates and Bill could use my heart rate to determine instantly that his was 20 beats higher than it should have been when he started exerting. It didn't matter that we'd never been on the particular trail before, I was his reliable reference point even as the levels of exertion fluctuated.

Until this day on Kaibab, comparing heart rates had always been meaningless entertainment. But fortunately, we'd entertained ourselves enough times with the comparisons to immediately know when something was amiss. And just as predictable as the spread in our heart rates is our different responses to the same long-term training stresses, like on this day. We'd been doing the same activities, but the recent pattern of activities had somehow pushed Bill's body over the edge and not mine. The reverse happened in the Alps when I couldn't rally to do one more pass: we'd ridden side-by-side for the previous months and Bill was fine and I was totally wasted. Even when we get the same bug, we don't get acutely sick at the same time and often have very different patterns of recovery. So we are lucky and know it: we can count on a change in the spread between our heart rates to reveal illness or overtraining in one of us. In future 'all-or-nothing' activities like hiking the demanding trails in Grand Canyon, we'll always take 2, not 1, heart rate monitor to reveal otherwise masked weariness.

"The Fountain of Youth Is in Using Your Body"
A lesson that I reject from this experience is "Don't push." The truth is that for most of us if you only go when you are tip-top, then you never go. But the situation with the woman being airlifted out of the Canyon with an orthopedic issue certainly hit home for me because she'd called it wrong while I also had been scrapping by with an undiagnosed knee/leg condition for the previous 10 weeks. Each day for months I'd have to decide whether I thought my recovery process will be helped or hindered by doing. I'd tackled the Grand Canyon trails with acute awareness of my vulnerability and been extremely deliberate on the downhills, which was my most vulnerable position. (Amusingly, I was irritating my knee more often when rising up from the toilet than on the trails.) And I'd carry several aids with me on hikes should it get fired up and I knew that I would have more will to get myself out of a pinch than to get into one.

Seeing the woman sit there for several hours in the hot sun (we saw her both before and after our lunch) unwilling to move herself to the nearby shade of the pit toilets told quite the tale. I would have borrowed a pair of walking sticks from passing hikers, hopped over on 1 leg, or crawled on my hands and knees to the cooling shade but she chose to sit and risk dehydration and overheating until 2 men carried her full and significant weight. She clearly had misjudged her recovery from her surgery or whatever it was; put herself on a familiar, but demanding trail; then expected others to literally rescue her. I believe one needs to push to their edge but that they also must have more resourcefulness than she demonstrated when things get dicey on the edge.

The park volunteer overseeing the woman's situation for hours took a break and shared her personal philosophy with us: "The Fountain of Youth is in using your body." I loved it. And using it means pushing it but with a back-up plan and with self knowledge.

Metabolic Chaos
We'd loved to have learned something significant about metabolic chaos from Bill's experience and seeing the spaced-out man on the trail, but we still struggle with the interpreting the details. Bill's heart rate fluctuations demonstrated that he benefited from the extra dose of sugar and salt, and it was probably the salt, but at what point did it matter? Was he salt-short after the Bright Angel trail exertion and did that trigger the overtraining-like increase in his heart rate? Was it overtraining that pushed his body into chaos so that its salt needs increased? We don't know the answer. A parallel and published observation is that when one is sleep-deprived that you feel and perform better if you increase your caloric intake but the problem isn't because of a calorie shortage. "Inefficiencies of chaos" is the extent of our understanding. So we'll continue doing what we did: when the body is messed up metabolically, shovel in more water, salt, and calories and hope it helps.

So What Was The Problem??
What It Wasn't
We were absolutely perplexed about what had caused Bill's meltdown. None of the obvious answers fit. Yes, we were at 7,000' but the hike was down and back up to that elevation and we'd been at that altitude for about a week. It wasn't really high enough elevation for altitude sickness and we'd been at that level long enough to be fully acclimated if it was.

The 3000' elevation gain on the Bright Angel Trail was easily within our range. Typically we don't do more than 4,000' gain in a day and we'd hit the 3,000' mark or close to it on several previous hikes this season. And a few days earlier we'd hiked from 7,000' to 9,300' at Flagstaff without any difficulty during or after the outing.

The heat was an important element, but clearly not the central problem. We'd hiked on a number of hot days in the last month, several that were hotter. And like on those hikes, the humidity was mercifully low, effectively reducing the potential heat burden a bit. And double checking how much we'd been drinking and peeing suggested dehydration wasn't a factor either.

There was no reason to think our fitness level wasn't up to the task. We'd been doing 5-10 mile hikes regularly, all with some or significant elevation gain and most in the heat. And the absolute lack of muscle soreness on any of the days suggested we hadn't outstripped our conditioning.

We kept wondering if there was something peculiar to the down-then-up regime that eluded us. We both had an unusual tightening in 1 hip muscle group (TFL's) that we suspected was related to the reversal in the stress sequence, but it was hard to imagine anything more.

Another Meltdown
Unexpectedly, Bill felt bad enough 24 hours after our return from Kaibab Trail to ask me to visit the Grand Canyon campground office before they closed for the night to get directions to the nearest ER. He felt non-specifically terrible, like with a flu, and was deeply concerned about the descent into next stage of whatever it was. I kept quizzing him about his condition and did a preliminary pack-up of the camper in case we needed to make a quick getaway. Fortunately his bad sinking spell self-corrected within an hour or so and he quickly shifted to feeling his best of the entire day.

While stretching the TFL hip muscle and others the morning after Bill's delayed sinking spell it finally hit: there were indeed 2 new variables we'd overlooked in analyzing his difficulties. One was that our training event of blasting up Bright Angel for 2 hours at a high heart rate was a first-time-ever experience. We didn't think much about it because we knew we were in good condition for the output and felt fine both during and afterwards, but it's extremely difficult to find a steep trail that allows one to push that hard, that long, even though we go looking for them. We have a favorite in the Dolomites that is 2,000' gain that we routinely complete in 45 minutes but on Bright Angel we sustained a similar level of effort for more than twice as much time. We were in new training territory and hadn't even noticed. We push ourselves for more hours cycling over mountain passes but when the effort is near our limit, we often stop to rest every several minutes, making it difficult to equate the exertion with that of hiking.

Recognizing the exceptional output as an issue was important but it alone wasn't the problem because we both did fine the following day with a moderately vigorous workout with 700' gain and some intensity. But perhaps it was the combination of the highest-ever intensity workout with insufficient recovery that was really the issue, with too little recovery time being the second problem. We'd given ourselves the usual 1 day of recovery after a big event and in hindsight the effort may have warranted 2 days of relative rest. Had we taken 2 easier days between Bright Angel and Kaibab there might not have been a hint that Bright Angel had been a stress. And unlike several other feats in years prior where our bodies shouted at us that we needed serious rest, only Bill's body spoke up and it only whispered the day after doing Bright Angel. We thought we'd figured it out but we were in for yet another surprise:

Bright Angel Trail as it approaches the Indian Gardens oasis.
"My Lab Rat Took 1st Prize!"
Fortunately Bill laughed heartily when I exclaimed "My lab rat took 1st prize!" while looking directly at him. He was still wearing the Flagstaff ER hospital gown that he'd been in for 18 hours when the doc said his heart and coronary arteries were clean, squeaky clean, as in zero plaque. We often joked about feeling like lab rats while we again tweaked our diets and health regimes to align with the cutting edge health recommendations and we'd just learned that all of our decades of compliance had done precisely what we'd hoped: returned our risks of heart attacks back to the pre-Industrial Age norm of zero. The EKG, ECHO, and CTA tests all indicated that Bill was essentially bullet-proof to heart attacks: if there is no plaque, there cannot be a heart attack.

On our last full day at the Grand Canyon I'd gone off alone on our 3rd scheduled big hike on Hermit's Trail while Bill stayed in camp, still not feeling quite right after his meltdown on hike #2 on Kaibab Trail 3 days earlier. His father's life-constricting heart attack at age 54 when Bill was 8 had left Bill feeling doomed to a similar fate once he turned 50. This bad family history had loomed large 24 hours after the 2nd hike when he felt terrible for 1-2 hours. The difficulty breathing, the subtle sense of pressure in his chest, the mild indigestion, and the lack of any other convincing diagnosis left him worrying about a heart event. Unbeknown to me, while I took a seat on a rock for lunch at Dripping Springs off the Hermit Trail, Bill was taking a seat in the reception area of the Grand Canyon Clinic.

I returned from my hike to find Bill gone and 2 messages on my cell phone, which were irretrievable because of some glitch in our poor service area. He'd mentioned that he thought he'd go to the park's Clinic for reassurance, so I used Skype to call them saying "I'm looking for my husband, has he been there?" "Yes, and you're going to the Flagstaff ER" was their reply. Dirty, sweaty, and hungry I shifted my attention from myself to readying the camper for driving and then picking Bill up at the Clinic. The Clinic doc and the consulting doc at the Flagstaff ER both shared his concern of a politely spoken 'cardiac event.'

But after a near-sleepless night for both of us and a bill that hit $5000 before they did the fancy testing, Bill's heart assessment flip-flopped from shared concern to "couldn't be better". All of those years of the anti-social shunning of burgers and fries, steaks, baked goods, and the like had paid-off big-time: they had rendered his dismal family history absolutely irrelevant. Heart attacks are a lifestyle disease and even changing his lifestyle at age 35 had been good enough to make his story drastically diverge from that of his father's. It wasn't until the clean report that he realized how heavy the burden of his family history had been for the last 10 years. And who could object to being called the lab rat with the 1st prize ribbon with news like that?

Hiking Kaibab revealed Bill"s metabolic stress from our big Bright Angel effort.
The cardiologist, the ER doctors, and the half dozen RN/athletes could only offer altitude as an explanation for what was ailing Bill. Clearly the altitude was a component because he immediately felt better when we dropped from 7,000' to about 5500' a day later, but it wasn't the whole story. The ER doctor's best advice was for Bill to limit his hiking to 2,000' elevation terrain. Her advice smacked of that I'd been given at age 20 to no longer go up stairs and at 35 to not cycle or run: advice that gets the doc off the hook at the moment but that results in early-onset of age-related disabilities for the patient. We thanked her and her department for their truly great care and accepted the fact that we were again on our own to devise an appropriate strategy to keep Bill active and doing the things he loved without triggering another revolt from his body.

After carefully reviewing his symptoms and current sense of wellbeing, Bill decided to head higher rather than lower: Bryce Canyon at 8,000-9,000' was next on the itinerary. The plan was to go there for 1 night and see how he did. If he felt distressed again, we'd immediately drop to lower elevations; if he felt the same, we'd linger longer. Luckily his body was indeed successfully recovering from its unidentified and expensive upset and we enjoyed 3 hikes and 5 nights at Bryce.

The Special Hazards of the Grand Canyon

Our hours spent in the Flagstaff ER resulted in hearing several thought-provoking stories from the local doctors about the special health hazards of the moderate 7,000' elevation of Flagstaff, which is also the highest elevation on the popular South Rim of the Grand Canyon. We heard about hardy mountain bikers developing deep vein thrombosis (DVTs) and pulmonary emboli (PE) from the altitude: conditions associated with the low pressure and hours of sitting that accompany long-haul air travel. The other ER doc told of acute kidney failure (that could require transplantation) in aggressive 20 year old male athletes from rhabdomyolysis--sudden and toxic breakdown of muscle tissue that can be caused by overexertion. Both of these physicians were baffled by the frequency with which they saw such catastrophic conditions in highly-trained, local athletes for no particular reason. Juxtaposing those unsolved mysteries with his own, Bill repeatedly said "The Grand Canyon is a more dangerous place than I realized."

Next time at Grand Canyon we'll acknowledge its special and poorly understood hazards by: again taking time to acclimate to the moderate elevation; only hiking while there and not doing high-output training events like we did going up Bright Angel; each wearing a heart rate monitor while exerting; allowing 2, not 1, recovery days after big hikes; and we'll cross our fingers that this plan is sufficient to keep us safe and feeling great.

Back Home
Three weeks after Bill's "event" we were back home and one of his first stops was to see his primary care physician. A highly trained athlete who draws athletes into his practice, he was quick to diagnose Bill with acute mountain sickness. "A classic case...I see it all the time...it may or may not ever happen again....."

Our elevation of 7,000' at the Grand Canyon was a little low for acute mountain sickness which is associated with elevations over 2,500 meters or 8,200' but we were sleeping at elevation every night, which is the opposite of what one should do for altitude acclimation, so we were comfortable with his assessment. He gave Bill a prescription for a medication used to fend off the condition in the future and said "Don't worry about it." And a work-up by a vascular surgeon a few weeks later confirmed that Bill didn't have any peripheral vascular disease either--another blue ribbon for the lab rat.