Mirinda Carfrae and Caitlin Snow Run Technique Analysis

I sat down with my laptop early this morning, intending to harvest YouTube for running footage of 2010 Ironman World Champion Mirinda Carfrae, to then perform a running video analysis for this blog. Since popularity of the Crowie Run Analysis, I thought it would be a natural next step.

Instead, a little bit of searching lead me to this great video analysis below. Coach Jesse Kropelnicki takes time to dissect the running techniques of both of Caitlin Snow and Mirinda Carfrae.

Hopefully it’ll prove interesting to share this video here.

Additional Observations

HIP EXTENSION (video time 1:20)

Although good extension is indeed a trait of all good runners, it’s very important to note where the observed extension is coming from.

How much is true Femur-on-Pelvis (Hip) extension? Concurrently we have to ask to what degree this desired extended position is achieved through excessive movement of the Pelvis, rotating forwards excessively in the sagittal plane?

While we expect to see Pelvic position change in all three planes of motion throughout the gait cycle, the changes in position should not be great in magnitude – providing a stable Pelvis and therefore maintaining muscular balance and helping to keep muscles around the Hips, Pelvis and Lumbar Spine working in optimal ranges of motion.

If we look at Mirinda (video time 10:38) we can see loads of good extension being achieved as a net result of all movements, as highlighted on video. However, also look how much of this is coming from the anterior rotation of her Pelvis (same side) during late stance phase, and thus increased Lumbar Spine extension, and compromised Pelvic position.

The oscillation stride by stride of Mirinda’s Pelvic position, and therefore Lumbar Spine posture is somewhat greater than I’d like to see, especially in the sagittal plane. This compromised Pelvic position can also have influence on Glute function in running. I’d be interested to know if she suffers from any lower back discomfort on race day…?

HIP FLEXOR RESTRICTION (video time 2:03)

I completely agree that in Triathletes in particular, Rectus Femoris or “Upper Quad” as cited in the video, becomes a limiting factor in achieving good Hip extension on a stable Pelvis. This isn’t helped I’m sure by endless hours on the bike, working into a Hip Flexion pattern, when running is a Hip Extension pattern!

In addition, as a point of note. When Rec. Fem. becomes overly active, and tight, Psoas (deeper Hip Flexor) often becomes weak. This can lead to Tensor Fascia Lata also becoming overly active in achieving inner range Hip Flexion in running. This can have implications including increased tension in the ITB.

CADENCE (video time 3:00)

If, as stated in the video above, Caitlin Snow really does run at a cadence of 95-98 strides per minute (one side), then wow! That’s a pretty quick turn-over.

I’m in no way saying that it’s a bad thing… In fact most age group triathletes and sub-elite runners will be running in the mid-to-low 80s at a tempo pace. More information on running cadence here.

ARM MOTION (video time 3:30)

Both athletes in the video above achieve and maintain great “active” arm motion, driving the elbows back with the elbows bent to around 90 degrees. So many age group triathletes and sub-elite runners will “go passive” with their arms, especially over longer distances in an effort to reduce energy expenditure, this is such a false economy!

The active motion of driving the elbow back – even just slightly when running slowly – helps to facilitate the desired motion of torso extension and (good) rotation as described below…

UPPER BODY ROTATION (video time 10:20)

Indeed, no runner should be trying to hold their upper body rigid and cut-out all rotation. Instead, appreciate that there are two types of upper body rotation in running:

– “Good” Rotation

The ‘good rotation‘ that I often refer to is the combined rotation and extension through the Thoracic spine and retraction of the Shoulders. These components are all lead by the motion of driving the Elbow back, helping to keep the Chest open. This enables the Anterior Oblique Sling System of core muscles to load and unload to contribute to an efficient running gait.

Both Caitlin and Mirinda are great examples of this good Upper Body technique in the video above.

– “Bad” Rotation

In start contrast, the “bad rotation” I see all too often in runners involves less of a drive back with the elbows, instead it is characterised by the hands drifting with less control across the front of the body, crossing the mid-line.

While we see perhaps even more rotation in the “bad” than in the “good” definition above, we also see Thoracic flexion and Shoulder protraction. Almost moving into a slumped position as fatigue kicks in. Not only does this position close up the Chest, it also inhibits the correct loading of the Anterior Oblique Sling System as described above. In addition, excessive and non-productive rotational momentum simply requires more effort to control.


Mentioned last for a reason. You can see that while neither Caitlin or Mirinda make ground contact under their Hips, they both make ground contact with the Knee beginning to flex over the loading Foot, rather than stretching the lower leg out to place the Foot ahead of the Knee. This is a key component of reducing unwanted loading, especially of the knees, allowing the knee’s surrounding large muscle groups to absorb impact.

You’ll see that both these athletes are heel strikers. They still run sub3 off the bike! For an Ironman athlete such as these two ladies, getting the above components right, including those mentioned in Jesse’s great video is far more important than forcing your body to learn to forefoot strike.

Read my thoughts on forefoot running for Ironman athletes here.

Last updated on March 2nd, 2021.

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