Physiology, the Runner's High, and the Power of Mitochondria

The joy of running can be addictive.
The joy of running can be addictive. Drewski Mac
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Sara Molskness just might understand the mood-lifting phenomenon of the “runner’s high” better than anybody. Not only does she run ultramarathons, she also holds a masters degree in exercise physiology. “For me, the runner’s high is real,” she explains. “And that’s why I keep chasing it.”

Sara makes her home in Asheville, North Carolina, and has participated in local distance races such as the Frosty Foot 50k, and the Pisgah Running Adventure Race. I sat down with Sara to discuss her training regiment, the benefits of running through the winter, and her fascination with all that the human body is capable of accomplishing.

Molskness running the Blue Ridge Relay.
Molskness running the Blue Ridge Relay. Courtesy of Sara Molskness

What are you currently training for?

I’m currently training for the 2016 Frosty Foot because I loved the first one so much last year. It takes place in January at Tsali. Then I’m going to do the Mt. Mitchell Challenge in February, which is a 40 mile race from Black Mountain to the top of Mitchell. It will be the longest I’ve ever done. I’m really excited, really nervous—feeling extreme on both ends.

You chose two ultra-races in the middle of winter. Do you like running in the cold?
I do like running in the cold. I’d rather be a little bit chilled than too hot. I grew up in a cold climate, in South Dakota, so I’m kind of used to it. Everyone asks me if I get that painful burning in my lungs, but I don’t. It’s just totally refreshing.

It can be tough to find the motivation to exercise in the winter. How would you encourage someone to get out and get running?

Endorphins. Running can be really intense, so you get that release of endorphins that is really noticeable after a hard run. It’s addicting. It gives you a high, a feeling of elation. It’s very powerful.

Running is also meditative for some people, and that’s another trigger for the release of those good hormones. Endorphins make you feel good in your body and mind. What’s cool is that the elation, the high—it’s all natural. It’s pretty fascinating stuff. For me, the runner’s high is real, and that’s why I keep chasing it.

How does your knowledge of exercise physiology influence your experience as an athlete?
It helps me to draw on the science of what the body is capable of. Many times, when I tell people what my intentions are, the first thing they say is, “Oh, that’s crazy! That’s too hard on your body.” They ask if I’m even capable of running that distance, and tell me I shouldn’t be doing it.

That attitude can affect me, and I sometimes question myself. But having an understanding of the human body and what it can accomplish helps to reinforce the knowledge that I can do this. The body is so adaptable, so flexible—we can train the body to do so much. If Frosty Foot was today, I couldn’t do it. The ability comes with the training process. I know I will be able to do it in January, because of the training process and the stressors I will put on my body to make it adapt.

What do you find the most fascinating about exercise physiology? 

I’m kind of obsessed with cell physiology and energy consumption. How does it all work? Where does our food grow? How do we get energy? The really cool thing about cells is that they have mitochondria, which are the powerhouse of the cells. People who exercise build up more and bigger mitochondria.

What’s the payoff of building super-mitochondria?

You have better metabolism and you’re better at metabolizing fat. In general, it takes a lot longer to start up your fat metabolism. It’s easy to burn up carbs and sugar really quickly, but it takes a lot longer to burn fat and boost your metabolism. Having more mitochondria will help you accomplish that.

Sara Molskness says her degree in exercise physiology helps her understand what the body is capable of doing in extreme endurance events.
Sara Molskness says her degree in exercise physiology helps her understand what the body is capable of doing in extreme endurance events. Trevor Reis

What is your training regiment for ultra-marathons?

The backbone of my training is weekly long runs. I increase the distance of the long runs 10 percent each week. I train on similar conditions as the race, so lots of trail running, hills and technical terrain. Further into the training process, I incorporate a second long run. Eventually I’m going to be running somewhere in the 20 mile range on Friday, and on Saturday I’ll do a shorter long run—10 or so miles. That way I don’t have to run for six hours straight, yet I can still stress my body and build that adaptation response.

I have one day of rest each week, and one day of cross-training, which for me is typically yoga. Another day is a somewhat long run that incorporates some speed intervals. Then I’ll have a shorter, easy recovery run, about 3 or 4 miles, where I just let myself run as easy as possible.

There is some mental and physical agony involved with ultra-marathons. Why do you run them? 

I like to push my own limits. I like to have something that I know I can’t do today, but I will someday be able to do it. Something out of reach. After I do a race, I get this feeling that I can accomplish anything. It helps me in my personal life to think, if I could overcome that, other problems don’t seem as hard. If I really do set my mind to something and set out a plan, then I can do it. My job is really stressful. And after my 50k, the whole week at work I was like, this is not a problem. This is not a problem. I can do anything.

You grew up in South Dakota. How did you end up in Asheville?

I moved here first because of the lifestyle. I didn’t have a job; the job came later. I love the trails, the quirkiness, the food, the overall scene. There’s a lot happening here. I was looking for the perfect place for a runner, and I chose Asheville. 

What are some of your favorite local trails?

Ingles Field Gap in Bent Creek. It keeps you awake. You can’t daydream too much when you’re on that trail. It’s really long, winding, uphill, rocky in places; it’s a good mental challenge. The Montreat Trails are also great for training because they’re extremely hilly. In terms of easier terrain, Carrier Park is nice and flat, and there's a greenway that runs from the park to Hominy Creek.

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