Ask a Trainer: Why Should Triathletes Care About Mobility?

A look at what mobility is, what it isn't, and why it's so fundamental to your success as you move across swim, bike, and run.

Mobility and flexibility are often used interchangeably, but they actually have different meanings. Mobility refers to joint range of motion while flexibility refers to the length of a muscle. It is possible to have flexible calves and at the same time immobile ankles. Tight muscles typically inhibit joint mobility so both need to be addressed. Semantics aside, when it comes to minimizing injury risk and improving performance, the key is the ability to move through the required range of motion for your activity. 

Think about mobility as it pertains to triathletes. On the one hand, we need enough mobility to swim, bike, and run. On the other, certain commonly used gym exercises, as well as daily activities, require more. Triathletes do not need to be able to touch their toes to get into a decent aero position, but they do need to be able to touch their toes if they want to incorporate exercises like Romanian deadlifts. When it comes to running, we need less ankle mobility than say squatting down and getting up from the floor. Let us take a page from Mike Boyle’s Joint by Joint approach. The approach looks to address the following questions: Do you have appropriate mobility where you should be mobile, and are you sufficiently stable in the joint systems that should be stable? Let’s look at these questions as they apply to triathlon.


When it comes to ankle range of motion, we tend to think sagittal plane, or toes up or down. While important, we also need to think about rotation. The ankle and foot are designed to absorb and disperse impact forces. When we lack proper ankle and foot mobility, we find movement elsewhere in the body and shift excessive strain to other soft tissues. 


Hips are an ongoing issue for triathletes. When hip extension is limited, we lose some degree of glute function and run form is impacted. When one muscle is tight it has an inhibitory effect on the opposing muscle. A lack of hip extension (tight hip flexors) will result in finding movement through the lumbar spine when running. Hip rotation plays a role in proper hip tracking and glute function as well.

Thoracic Spine

Thoracic spine mobility is one of the most neglected areas for triathletes. And when we are talking T Spine we need to include shoulders. One impacts the other. Thoracic extension allows for a better aero position on the bike, less neck stress, and a more streamlined position in the water. Shoulder mobility impacts your position in the water as well. On land, a lack of Thoracic extension and/or asymmetrical rotation will impact running posture leading to inefficiencies.

Grey Cook of Functional Movement Systems says first move well then move often. Triathletes certainly move often but not always well. A simplified way to look at mobility is identifying the postures you are in throughout the day and incorporating movements in the opposite direction. I have included a series of mobility techniques to address the areas mentioned in this article. First move well then move often.

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A 5-Week Plan For Improved Strength and Mobility

At the end of last year I built out a month-long challenge that focused on three parts of strength—mobility, balance, and core. If you’re lacking in mobility, this would be a great program to incorporate into your triathlon training. To get started, you’ll do three simple tests of your mobility, balance, and core. You’ll then follow the workouts (ideally three times per week) and repeat the three tests at the end.

Or: Try This Standalone Mobility Workout

If you’d like to fit a solid mobility workout into your program but don’t want to follow a month-long plan, see my standalone workout suggestion below. You can do the whole thing through, or focus on the areas where you lack mobility.

Kevin Purvis is a certified personal trainer with the National Strength and Conditioning Association. He’s based in Boulder, Colorado, where he works with a number of endurance athletes.

Exercise Sets x reps Video Link
Mid Foot Mobility 1x
15 sec roll
10 cross friction
5 wrap and spread
Ankle Mobility 2x 10 Video
Hip Extension 2x 5 each side Video
Hip External Rotation 2x 4 each side Video
Thoracic Extension 3 reps in each of the 3 positions Video
Runner’s Lunge w/Rotation x3 reps each movement each side Video
Toe Touch Squat x5 Video
Triangles x3 each direction Video