Life Time Run
Mary-Katherine Fleming
Centennial (CO)

How I became a runner is one story that stems back to my father's first heart attach and quintuple bypass when I was 6 year old; how I eventually became a coach is a separate story altogether.

In 1983, I started jogging with my dad every morning as part of his rehab. I'm a morning person by nature, else this habit might not have stuck, especially since my tiny, rural high school did not have track or cross country teams! I continued running off and on through high school and then looked for something a bit more regimented in college and stumbled into marathon training. I moved oversees after graduation in 2000 to work in finance, moved back to the US to earn MBA and MA degrees, got married, and with a few notable exceptions, ran and raced two marathons every year: one for 'fun' in the spring and one for 'performance' in the fall.

Five months into my second pregnancy my husband was relocated to Denver, a mile above sea level, where climbing the five stairs to our front porch would wear me out completely. Denver is a mecca for elite and competitive runners, yet I couldn't find any coaches who were confident and experienced in working with a postpartum mama who also happened to be new to altitude. So I decided to be the coach I needed to hire. 

I tumbled down a rabbit hole of cardio maximization, physiology, online courses, used textbooks, and #allthescience. I devoured everything I could read with regard to running - and I still do. I created a plan with sessions logged by time, not miles, and with firm heart rate caps, not dissimilar to the method my father used when he was recovering from his heart surgery in 1983. 

Compared to most coaches, especially the incredible group at Life Time Run, my background is non-traditional. I am not elite and never have been. People who knew me growing up don't think of me as an athlete (including my parents!) That said, I love running, work hard, and expect a lot from my body. Running has been the best part of my life for as long as I can remember. My view on running extends way beyond a single training cycle because I want to be doing it throughout my life time. My best is yet to come - and so is yours. 

I love working with runners of all levels, especially beginners and postpartum women, but THE most important aspect of coaching is fit. I would love to speak to you on the phone and see if I could be a good fit for your needs!

Connect with MK


  • Beginners
  • Postpartum training for moms
  • Road races 5K - Marathon

Education & Certifications

  • RRCA Certified Coach
  • LTR Certified Coach
  • MBA