CrossFit, once a quietly growing fitness trend, has officially hit the mainstream. While some consider it a cult among fitness enthusiasts, I would describe CrossFit as a strength and conditioning approach that incorporates functional fitness, gymnastics, Olympic lifting, explosive moves, and other fitness hijinks into a constantly varied and intense workout. The randomness of each Workout of the Day (WOD, in CrossFit-speak) is intended to improve your strength for anything and everything.

I need to make clear up front that I am a believer in CrossFit. I took my first class two years ago, showing up on the recommendation of my friend Darcy Franklin, a fellow runner (3:06 marathon) and triathlete who had just become a certified CrossFit instructor. I didn’t know what to expect, other than that the intent of the program was to get stronger. At the time I was six months out from having my fourth and final baby and I was tired of throwing my back out carrying car seats or lifting a child out of the bathtub; I needed to train for parenthood as much as for my next triathlon.

I loved CrossFit immediately and was highly motivated to return each week (yes, I only went once a week, which I still argue is a great start; CrossFit recommends four to six times per week). My reasons for liking CrossFit are simple:

1. Olympic lifting, a new skill for me, produced the same endorphin high as a good run.
2. As hard as the workouts were, I could always scale them to my ability; so could the grandmother or the high school athlete working out with me. 
3. I tried things I never thought to do: handstand pushups, rope-climbing, ball slams. These workouts were my regular dose of bad ass.
4. My aches and pains subsided; I didn’t have the need to visit my chiropractor as often.
   
5. I regularly received compliments on my muscular arms.

I soon learned about a subset within CrossFit called CrossFit Endurance, created by Brian MacKenzie to offer targeted CrossFit workouts for sport-specific athletes. MacKenzie knew he needed a different approach after a grueling 100-mile-per-week regimen while training for an ultra-distance run. “[People think] more is better. I’ve been there; I know that,” says MacKenzie. “I am still somebody who would prefer to go run a very long time and suffer, but I also know what happens with that. It doesn’t get me faster or fitter.”

As a seven-time marathon finisher and two-time Ironman finisher myself, I know what MacKenzie is talking about. That’s why when Franklin set out to scratch her typical high-mileage training program for a CrossFit approach, I followed along with great interest. While she didn’t run as fast or faster, I found it compelling that she ran a 3:30 on 25 miles per week. Her longest run? Nine miles. “I didn’t hit the wall,” Franklin says, adding that she’s not sure if that was because she was more mentally tough, physically stronger, or that she was overly conservative with her pace. “I had never trained like that before and I wasn’t sure I could finish.”

As a working mom of two, she says she’ll take the slower finish because she values what she’s gained: more time, because she spends less time training; no marathon training injuries; and a faster recovery. “I was able to squat the day after doing a marathon,” Franklin remembers. “I could walk up and down stairs.” In short, Franklin’s running didn’t get faster, but in her opinion it got better.

What makes CrossFit Endurance different? The program emphasizes technique and intensity, and takes a pragmatic approach to volume. “The key ingredient is skill,” MacKenzie says. “It’s running technique. People miss that. Everyone just wants to lace up their shoes and not think about what they’re doing. Slogging on the side of the road doesn’t mimic what real running is.” [Watch this example of MacKenzie correcting running technique.]

“Strength and conditioning teaches the body to use more muscle fiber, which you can’t do if you’re only ingraining the same pattern over and over,” MacKenzie adds. Improved running technique will improve efficiency and prevent injuries. Strength will improve speed and endurance. “Strong tissue doesn’t break down,” MacKenzie says. “Our limiting factor isn’t aerobic capacity; it is the tissue’s ability to hold up.”

The ideal CrossFit Endurance plan consists of three days of training followed by one day off. MacKenzie says a CrossFit Endurance athlete will achieve her best fitness with four to six CrossFit workouts a week combined with three to four sport-specific workouts. 

While I may have started CrossFit to feel more confident in my workload as a mother, when the next race season came I posted faster run times, even though I wasn’t running more. The only difference to my training was CrossFit. 

Sandi Strobel, 26, from Harrisburg, Pennsylvania, was amazed at the difference between her pre- and post-CrossFit pace when participating in marathon relay races six months apart. The first race she clocked a 9:15 pace; after training with CrossFit she ran a 8:32 pace. “I’m not a fast runner by any means, but I have seen definite improvement since I started CrossFit, which is even more remarkable because I actually run fewer miles now,” says Strobel, who has been a runner for 13 years and started at her local CrossFit in 2011. “When I was strictly running, I ran six days a week, with a weekly mileage between 35 and 40 miles. Since starting CrossFit, I run three to four days a week and top out around 20 to 25 miles per week.”

Strobel likes the total-body conditioning CrossFit offers as well as the coordination involved to get her muscles to work together. “Plus, almost all of the WODs are done for time, so you work on your speed as well as your strength.” Another advantage is the mental toughness: “CrossFit really teaches you to endure and push yourself.”

A few months ago I started adding a second strength day to my week with the aim of using it to help me reach my 2012 goal: to break my 20-year-old 5K PR.

Tell Us:  Have you tried CrossFit? Why or why not? Do you think it could help make you a better runner?

—Kara Thom, Runner’s World Reporter

Photo Courtesy of Darcy Franklin