Anggriawan Sugianto

Before you train for 170 kilometers, you need to understand how your body actually moves.

Not how you think it moves. Not how it looks in the mirror. How it actually moves under load, on fatigue, on mountains.

Most runners skip this step. They see a training plan, they start running, and they wonder why they get injured 12 weeks in.

The reason: they never did a baseline assessment.

In 2024, I spent time understanding my movement patterns. Not in a gym. In the real world: on roads, on trails, on mountains, under different conditions.

What I discovered surprised me. I had physical characteristics and movement tendencies I wasn't fully aware of. Asymmetries that would eventually matter if I didn't account for them.

This post is about how to do the same for yourself.

Finding Your Natural Stride and Biomechanical Biases

There's no "perfect" running form. There's your running form. Your unique way of moving based on your body structure, your anatomy, your neuromuscular patterns, and your movement tendencies.

A biomechanical bias is a natural tendency in how you move. For example:

• You might naturally land more on your forefoot even when running easy
• You might have a tendency to overstride on descents
• You might lean forward from your ankles instead of your hips
• You might rotate your hips excessively when climbing
• You might externally rotate one leg more than the other

None of these are "wrong." They're just how your body is built. But if you don't understand them, they can become injury vulnerabilities.

In 2024, I asked for feedback on my running form from the Pocari Sweat Sport Science team when I was pacing in a race. They gave me valuable insights about my movement patterns. 

Later, I also learned that some runners in the community ask Dr. Maria (on Threads) for running form analysis, which is another great resource.

My own patterns:

• My natural cadence: I run at 173–177 steps per minute depending on the distance and effort. In 2025, my road marathons had a cadence around 173 spm (slightly below the often-recommended 180 spm, but efficient for my body). On my 10K race, it was 177 spm (faster pace, naturally higher cadence). This tells me my stride adjusts appropriately to effort level.
• My foot asymmetry: My right foot is 27.1 cm long, while my left foot is 26.9 cm—a 2 mm difference. My left foot is slightly wider than my right. This 2 mm difference might seem tiny, but it can create asymmetries in how I land and propel myself.
• My strength symmetry: I don't know if one leg is significantly stronger than the other. Both feel similarly strong. But I'm aware that I need to address strength training more consistently.
• My descent pattern: I have a tendency to brake excessively on downhills. This is where I see the most room for improvement in my form.

How to find your own patterns:

1. Film yourself running (from the side, from behind) on flat ground, on a hill, on a descent
2. Look for asymmetries (does one leg land differently? does one foot point differently?)
3. Check your foot characteristics (measure your feet; notice width, arch height, toe flexibility)
4. Ask the running community (post videos to group or submit to coaches like Dr. Maria for analysis; others see things you miss)
5. Note what feels easy vs. hard (climbing feels hard, descending feels easier—or vice versa?)
6. Get professional feedback (race organizers sometimes have sport science teams; use them)

Your movement patterns aren't good or bad. They're just data. And data helps you prevent injuries and move efficiently.

Back and Hip Health: What I Don't Have Issues With (Yet)

I don't currently have back pain or hip pain. I sit at a desk 8 hours a day, but I've never experienced lower back pain that interferes with running.

This doesn't mean my back and hips are perfect. It just means they're not currently problematic.

However, I'm aware that ultramarathon training demands a lot from these areas. Running for 30+ hours straight puts stress on the back and hips in ways that shorter runs don't.

What I don't know:

• Whether my left hip is stronger than my right, or if they're balanced
• Whether my glutes are underactive or overactive
• Whether I have movement patterns that will eventually cause problems

What I do know is that I need more strength training. In 2025, during my peak training period before my first 100K ultra trail, I only did 1× strength training per week. That's insufficient.

For 170K training, I'm committing to more consistent strength work—not because I have pain, but because ultramarathons demand resilience from muscles and connective tissues that desk work weakens.

What to assess if you're healthy:

• Hip mobility: Can you do a deep squat? Can you do a 90/90 stretch?
• Back extensibility: Can you touch your toes? Can you arch backward comfortably?
• Core endurance: Can you hold a plank for 90 seconds?
• Glute activation: When you stand on one leg, do you feel your glute working, or is your hip flexor doing the work?

If all of these feel okay, you don't need to address them urgently. But adding preventive strength work (2–3× per week) will protect you during high-volume training.

Distal Foundations: Foot and Ankle Characteristics

Your feet and ankles are your connection to the ground. Everything that happens above them is only possible because of what happens below them.

In my case, I have a 2 mm asymmetry in foot length (right foot longer), and different widths (left foot wider). This is anatomically normal and doesn't cause problems. But it's information I have about myself.

More importantly, I know I have a history of right plantar fasciitis. This happened during the BDG Ultra 64K in 2024, when I ran downhill on macadam (asphalt) surfaces. The repetitive impact on the descent irritated my right heel.

My approach going forward:

• Shoe selection: Make sure I have shoes with adequate cushioning for descents
• Descent technique: Practice descending with better form to reduce heel strike impact
• Foot mobility: Regular calf stretches and plantar fascia release work
• Terrain awareness: Be cautious on asphalt descents in particular

What to assess about your own feet:

• Foot structure: Measure your feet. Are they similar length and width? (Asymmetries aren't bad; just know about them)
• Arch height: High arches, low arches, or normal? (Affects shock absorption and pronation)
• Toe mobility: Can you spread your toes? Can you curl them? (Important for ground feel on technical terrain)
• Injury history: Have you had plantar fasciitis, ankle sprains, or other foot/ankle issues? (These are vulnerabilities to protect)

Your feet carry you 170 kilometers. Understand how they work and what their vulnerabilities are.