What happens when
a soft-around-the-
middle weekend warrior
who’s staring down his
40th birthday heads
to the University
of Colorado’s Human
Performance Lab?
One man’s quest to
rediscover his fitness.
By Geoff Van Dyke
January 2014

Photo: Dan Saelinger

In endurance sports, there are two distinct forms of suffering: There is pain, and there is humiliation. These things can be discrete, but they are not necessarily mutually exclusive—and, at the moment, I am experiencing both pain and humiliation in the name of research and personal betterment.

It’s a cool spring day in Denver, and I’m running. Not outside in Washington Park or along the Cherry Creek Trail, two of my occasional routes. No, I’m running at progressively increasing speeds on a treadmill in a windowless room at the Human Performance Lab at the Anschutz Health and Wellness Center, located on the University of Colorado Medical Campus. Dr. Iñigo San Millán, the director of the lab, is my taskmaster this afternoon as I undergo what the lab literature refers to as a comprehensive physiological and metabolic test.

If the phrase “physiological and metabolic test” sounds innocuous, the real thing is anything but. First, I am stripped down to my running shorts and placed on a scale (186 pounds). Then, the doctor uses calipers to pinch me—everywhere from my triceps to my waist and from my thighs to my calves—to determine my body fat percentage (20.2 percent). Next, I wrap a heart rate strap around my chest, and San Millán places a plastic-and-rubber mask over my nose and mouth and invites me onto the treadmill. The mask measures the gasses I exhale and allows San Millán to analyze my oxygen consumption and how efficiently—or inefficiently—I’m using that oxygen as I run. Every five minutes, San Millán pricks a finger on my right hand to collect a blood sample to measure lactate buildup. Then he increases the treadmill speed another half-mile an hour. I run until I can run no longer, and then the test is over.

Why would anyone subject himself to this voluntarily? Trust me, there are many times that question crosses my mind during the approximately 35-minute test. The truth is, I’d signed up for this for one simple reason. At age 38, I’d fallen into a downward spiral of disgust when it came to my general health and fitness. The demands of a full-time job, and of being a husband and a father of two young boys, had sapped any desire to be physically fit, let alone to compete in weekend fun runs and the occasional half-marathon—pursuits that are practically required when one lives within the sunny, endorphin-obsessed borders of Colorado.

Actually, that’s not totally accurate. I wanted to be fit; I loved the idea of being in shape. Before we had kids, I had been a dedicated recreational cyclist and a sporadic runner and had raced in sprint and Olympic-distance triathlons. The myriad benefits of setting goals, training, and meeting those goals were not lost on me. My problem now was I didn’t want to do the work to get fit. Don’t get me wrong, I wasn’t flirting with morbid obesity and no one would’ve thought I looked out of shape, but I was tired, lazy, lethargic—a 30-something cliché. There were moments when, after putting my six- and four-year-old sons in their rooms for “quiet time” on Sundays, I’d lie down for a nap and wonder if I’d ever feel not tired again. On weekdays, rather than going for a ride or a run after work, I was more than content to eat dinner, watch the Daily Show with Jon Stewart, and knock back a few too many beers before climbing into bed and doing it all again the next day.

So here I am, sucking wind on the treadmill at the lab, hoping to perhaps put an end to the rut I’d found myself in, when the man who would be my guide, San Millán, walks over and puts the brakes on things. “Whoa, whoa, whoa!” he says, before hitting the down arrow on the control board to decrease the treadmill’s speed. “You’re stressed, aren’t you?” San Millán asks, meaning not that I’m anxious about the test (although I am), but rather that my body is being taxed beyond its meager ability.

“Yes,” I gasp through the mask. There is a short pause.

“I’ve got to be honest,” San Millán says. “You’re not nearly as fit as I thought you’d be.”

Stroll through any park in Denver on a weekend morning, and chances are someone will be doing something crazy in an effort to get (or stay) in shape. They may be slinging kettlebells; running wind sprints interspersed with push-ups, sit-ups, and four-count burpees; or carrying giant logs around on their shoulders. They’ll likely be doing this with five or six or 10 other Coloradans, all of whom will be sweating through their wicking workout shirts and looking equally ridiculous.

Head to any local gym, and you’ll see the same thing: The variety of spin classes is mindboggling. Zumba and water aerobics abound. Here along the Front Range, there are bodyshaping boot camps and pole dancing fitness classes and workouts that use the bleacher seats at Red Rocks as an outdoor StairMaster. And, of course, there’s what can only be described as the CrossFit phenomenon.

But that’s not all. There are corollary diets (hello paleo!) and self-help books to complement nearly every new fitness craze. To wit: In 2010, Timothy Ferriss had a New York Times best seller with The 4-Hour Body: An Uncommon Guide to Rapid Fat-Loss, Incredible Sex, and Becoming Superhuman. (Apparently, understatement is not one of Ferriss’ fortes.) Lance Armstrong’s former trainer Chris Carmichael, who’s based in Colorado Springs, has published both The Time-Crunched Cyclist and The Time-Crunched Triathlete in an effort to tap into the massive market of weekend warriors who, like many Coloradans, have full-time jobs and busy lives but still want to compete.

As my 40th birthday loomed, I wasn’t so much thinking about competing as I was hoping to remove the couch pillow that was firmly stuck to my backside. But with all the noise out there, I had no idea where to start. Frankly, it all sounded awful to me, which made me realize my success hinged upon finding something I could believe in. I didn’t want something that might work but would make me miserable in the process. I didn’t want to slip a disk doing exercises that seemed better suited to burly lumberjacks. I wanted something that was proven, something backed by real science.

Fortunately, I live 10 miles from a place where exercise and science are beautifully wed. The Human Performance Lab is part of the almost-twoyear-old CU Anschutz Health and Wellness Center in Aurora, a temple to better living through scientific research and methods. The word “wellness” often conveys a laid-back, Left Coast, granola vibe; this center is anything but. Walk through the front doors, and you’ll feel as if you’ve entered a futuristic Steven Spielberg film (in the best possible way) as you embark on your—cue voice-over—“journey to optimal health and fitness.”

San Millán’s program has been forged in the furnace of professional athletics; he’s tested or trained dozens of elite athletes, including Tour de France winner Alberto Contador and Giro d’Italia winner Ryder Hesjedal. But what gives him even more credibility is that he’s a scientist first, not a coach or a trainer. San Millán’s goal at the lab, in addition to working with elite athletes, is twofold: to bring scientifically proven training methods to average Joes, and to help people who have weight issues, diabetes, and chronic disease return to health using those same programs, modified for each individual. “There are so many training plans out there,” he told me. “But most people have no idea what they’re doing. People sign up for Internet coaches, they never actually meet them, and the result is they get a onesize- fits-all program. Inevitably, they get injured or burned-out or depressed—I see this happening all the time.”

Ultimately, that’s why I ended up in San Millán’s lab. I figured he might give me my best shot to get where I wanted to be through his tailored physiological testing. For less than it costs to buy a high-end treadmill (the initial test is $449; a follow-up will run you $350), he and his state-of-the-art lab were going to give me an easy-to-understand plan that I could post on my corkboard at the office. If that meant I had to suffer on a treadmill with a mask on my face to reboot my body’s ability to be fit, well, then, so be it.

Still winded from the treadmill test, I showered and returned to the lab, where I sat munching on a granola bar while San Millán pulled up my personalized “Physiologic Performance Evaluation”—my fitness report card—on his computer screen. The good news was I wasn’t failing. The bad news was I wasn’t an A student. I was thoroughly average: “In general,” the evaluation read, “the physiological parameters observed are normal for the age. However, these parameters can improve with specific training and time in order to achieve a better fitness level as well as for performance purposes.”

I guzzled some Gatorade as San Millán pointed to a graph that tracked my heart rate and the amount of lactate buildup from the treadmill test. My body’s ability to remove lactate, a byproduct of increased exercise intensity, needed work. And my capability for using fat as fuel had room for improvement, too.

San Millán’s terminology was familiar, but even though I’d dabbled in endurance training in the past, I had no idea how to remedy the esoteric physiologic problems I never knew I had. What I did understand was this: My body wasn’t working efficiently, which is why I was running slowly—and why I was suffering while I was plodding along on my occasional runs.

San Millán and his team understand that their clients don’t know how to fix these things, which is precisely why hundreds of people visit the lab each year. San Millán is a bona fide exercise whisperer. The funny thing is that what he tells me is so simple: It’s all about training for certain amounts of time at specific and optimal heart rates. The mileage I accrued didn’t really matter. By studying multiple factors from my test—the progression of my heart rate, how effectively my body was using oxygen, how much lactate was building up in my blood—San Millán was able to give me personalized heart rate “zones.” Every person’s heart rate zones are different, and that’s thepoint of the painful treadmill test—to determine the right zones for you. The six San Millán assigned to me ranged from “recovery” (also known as Zone 1) to “anaerobic” (Zone 6, also frequently referred to as the “red zone”). In Zones 1 and 2, my body would primarily burn fat as fuel and help build my aerobic “engine.” In Zones 3 and 4, my body would mainly burn glucose (broken down from carbohydrate) and improve power and speed. Finally, in Zones 5 and 6, my body would tap into the fight or flight mechanism and burn something called adenosine triphosphate (more commonly known as ATP), an energy source stored in our muscles in small amounts.

San Millán explained he wanted me to train mostly in Zone 2, which meant my runs would be really slow—like 10- to 11-minute-miles slow. But this leisurely pace was precisely what would teach my body to burn fat more efficiently; it would work my slow-twitch muscle fibers, and it would give me a solid fitness base on which to build. In order to get fitter and faster, going slow was the doc’s first prescription.

In order to get fitter and faster, going slow was the doc’s first prescription.The goal was to do three 60-minute-long runs a week for three months, which seemed eminently reasonable. But it wasn’t easy at first. If you’re not fit, there’s no getting around the fact that an hourlong run hurts, and pain is a serious demotivator. On top of that, getting going was difficult because, you know, I have a life. I don’t work out in the morning because, for me, sleep is more important than exercise. And, let’s face it, with two young boys and two parents who work full time, mornings at my house are chaotic enough without me heading out for a 10K first thing. That meant my training runs would have to take place after work, which posed its own set of challenges. I wanted to see my wife and boys at the end of the work day, or I wanted to grab a quick beer after work with my colleagues. So I faked it for a while after that initial screening. For the first two months, most of my runs were closer to 50 minutes than they were to 60, and although I did my best to get in three runs a week, I didn’t always succeed.

But here’s the thing: It was still working. Even though I wasn’t fully toeing San Millán’s line, I was building that all-important base. And finally, slowly, I started to feel a little better on my runs. I figured out ways to fit my workouts into my schedule (which often meant running in the dark after my boys were in bed). I’d pop my earbuds in and head out for an hour, and I’d actually enjoy it. I’d get lost in the audio book I was listening to, or a new album, or simply the sound of my shoes on the hard dirt path.

San Millán suggests his clients return to the lab two to four months after their initial test. I’d hoped to do that, but…stuff happens. Parent-teacher conferences, Home Depot trips, meetings, coffee-this and lunch-that. Nine months after the first treadmill test, I finally worked in an appointment with San Millán. I had mostly kept up with the basic training, but going back to the lab felt a little like going to the dental hygienist; it was as if I’d tried to floss every day but was still worried about what she’d say when she finally took a good look. Fortunately, the news was positive. I’d lost seven pounds, and my body fat had decreased by three percent, to 17.2. On top of that, I’d made strides in my fitness. My evaluation said I now had “a good aerobic base,” my body had gotten better at burning fat, and I was clearing lactate out of my system more efficiently. San Millán’s program was working, and that was exciting—and a little bit addicting. I wanted more. It was then I set a concrete goal: I would run a personal best in what would be my fifth half marathon.

That San Millán didn’t raise an eyebrow when I told him my ambition was reassuring; however, I knew if I was going to meet my goal, the serious work was yet to come. “Let me show you something,” San Millán said in a tone that suggested he was going to let me in on one of life’s great secrets. He pulled up a PowerPoint presentation on his computer that had a variety of charts and photographs. Two of the images were black-and-white photos. “See these?” he said as he pointed to a long, narrow shape in one of the images. “That’s what your mitochondria looked like when you first came to see me.” Then, he pulled up another image and pointed his pen at it. The shape was robust, almost round. It was an “O” compared to the “I” in the previous image. “These are the mitochondria in an elite endurance athlete.”

I hadn’t come to San Millán expecting a lesson in basic biology, but that’s exactly what I was getting as we set out to map a fitness program that would prepare me to reach the finish line faster than I ever had before. And the session’s simple takeaway was that my mitochondria—more colloquially known as the cell’s power plants—sucked. They were weak, feeble, and frail.

San Millán explained that my fitness—everyone’s fitness—is less about having monstrous biceps, a strong heart, and big lungs; it’s really about what’s going on at the subcellular level. If a person’s mitochondria aren’t functional, not only will he be out of shape, but he’ll also be at risk for developing metabolic diseases like type 2 diabetes. “Think about it,” San Millán said. “Elite endurance athletes are the only population on the face of the Earth who don’t have any metabolic disease. There’s a reason for that.” And that reason is their mitochondria can oxidize fat and lactate at extraordinarily efficient rates. “These guys,” he says, pointing to the image of the mitochondria, “do the magic.”

My revised training program had me continuing to build my base fitness—and, in the process, improving the volume and size of my mitochondria—for about three months. Then I would embark on a subsequent, different three-month plan leading up to the Denver Rock ’n’ Roll Half Marathon in October.

The pre-race regimen, which San Millán gave me in the form of an easy-to-read weekly grid, was remarkably uncomplicated. Most weeks called for four runs—which, for me, meant running on Tuesdays and Thursdays and on both weekend days. Two of the runs each week were easy Zone 2 runs ranging from 60 to 90 minutes. (Because my fitness had improved, San Millán tweaked all of my personalized heart rate zones accordingly.) The other two sessions were 60 minutes and included two “lactate threshold” Zone 4 intervals. Each month of the program called for three weeks of serious workouts followed by a recovery week of very easy, shorter runs.

That’s it. There was no weight training. There was no stretching, although I’d warm up for each run for five to 10 minutes by alternating easy jogging and walking (current research shows that static stretching may actually harm, not help, performance). And the diet—really just a nutritional tweak for me—San Millán prescribed was reasonable. For lunch, I limited the burritos and tried to stick with turkey or roast beef sandwiches. I had normal dinners with a glass or two of wine, which San Millán had said was OK. (I may have interpreted that loosely and applied it to beer, and whiskey, too.) The biggest dietary change I made was switching my breakfast routine from Greek yogurt and a granola bar to a bagel with low-fat cream cheese. “You’re going to need more carbs,” San Millán said. I happily obliged.

In the three months leading up to the half marathon, I missed just two workouts. Sometimes I’d modify things slightly: I did some longer runs so I had the confidence of having logged 11 or 12 miles before the 13.1- mile half. If my body wasn’t feeling up to it on a given day, I’d skip an interval. But I largely stuck to the program, and about halfway through—roughly 14 months after my fi rst visit with San Millán—something clicked. My body had changed. I could feel it. I was feeling…good. My per-mile pace was improving when I ran at the same Zone 2 heart rate. My blue jeans began to hang on my hips. I was sleeping better. And the confidence that came with applying myself to something and knowing I was making progress put me in a good space psychologically.

A week before the race, I felt prepared: no injuries, no illnesses, not a hint of lethargy. I ran three times that week to keep my legs loose, cut back on the wine, and prepared mentally for the race by envisioning difficult parts of the course and how I would power through them.

“But most weekend warriors are still doing the exact opposite of what the world-class athletes are doing.”The morning of October 20, 2013—race day—was cool and overcast, perfect running weather. My mind was calm. I was ready. When the starting horn sounded, I set off loaded full of the adrenaline that comes from running with 15,000 other people. My goal was to stay within myself early, to not go out too fast; about a mile in, however, my heart rate monitor went haywire and indicated that my heart was beating 234 beats per minute. I knew that wasn’t the case, based on my easy breathing (I was also pretty sure it was physically impossible). When the monitor fi - nally settled down, I too settled into a comfortable pace. In previous races, I’d always had people running past me, right from the start, which was thoroughly discouraging. This time, however, I was the one doing the passing.

At mile five, I was about a minute and 45 seconds ahead of where I wanted to be, and I was feeling great throughout the race—until a slight hill near Cheesman Park around mile 10.5 challenged me. Even then, as the doubt that comes with pain began to register, I was still passing people. A slug of water helped me push through. Two more miles, I thought. This is why you did all those intervals. Roughly 18 minutes later, after cruising down 13th Avenue toward the titanium-covered facade of the Denver Art Museum, I rounded the corner toward the fi nish line and gave a little kick. I checked my time: 1:55 flat, a personal best by almost eight minutes.

A week and a half later, I drove out to Aurora to hit the treadmill one last time. Like a kid who knows he got all A’s, I wanted that final report card. And, after suffering through the physiological test for a third time, I would finally be able to see how far I’d come looking at San Millán’s numbers and charts. My body was clearing lactate, in some cases, four times more efficiently than my first test. And my cells had finally learned to efficiently burn fat as fuel, as evidenced by the fact that my body-fat percentage was down to 15.5 and I’d dropped 5.5 more pounds to land at 173.5—right where San Millán thought I should be.

I was also right where I thought I should be with three months left before the big 4-0. Yes, I’d had fairly modest goals when I began my fitness quest, but those objectives actually matched up perfectly with San Millán’s commonsense approach. “People read these blogs and articles that say, ‘If you only have one hour to exercise, you better do your workout as hard as you can because it’s the same as if you were to exercise longer at a low intensity,’ ” San Millán told me at our last meeting. “No, it’s not. We can’t be so naive to think the best coaches and athletes in the world haven’t thought of that. They’ve tried it—and it doesn’t work. But most weekend warriors are still doing the exact opposite of what the world-class athletes are doing.”

Colorado, of course, is full of weekend warriors. The triathletes. The cyclists. The trail runners. And the people struggling mightily to hoof it around City Park or ride their bikes up Lookout Mountain. Like me, they are all looking to be a fitter version of themselves, and with the benefit of hindsight, it’s a little disheartening that so many of them are putting in so much effort—and money and time—and gleaning so few results when simple, effective science is as close as a treadmill in Aurora.

I’ll keep the knowledge that I’m one of the fortunate ones who found the Human Performance Lab tucked away in my mind as I try to maintain the gains I made over the past year and a half. And I will do my best to remember my answer when San Millán asked if I could continue to do two or three easy hour-long runs each week. “So many people can’t keep up with their training plans,” San Millán said. “But this is something you can do for the rest of your life, right?”

“Sure,” I said. “No problem.” And with that, my fitness reboot was complete.