Anggriawan Sugianto

Most runners have a gap between where they think they are and where they actually are.

It's not malicious. It's not ignorance. It's just how brains work—we're optimistic about ourselves. We remember our good runs and forget the bad ones. We imagine ourselves stronger than we actually are.

But there's a cost to this optimism: you set goals that don't match your current fitness, and you get injured or burned out trying to reach them.

In early 2026, before I committed to the 170K goal, I had to answer an uncomfortable question: Am I actually ready to attempt this, or am I just wishful thinking?

The answer required brutal honesty about where I actually was.

BDG Ultra 100K - My longest run so far.. 30 hours+

VDOT and Training Paces: Your Actual Fitness Level

One of the most useful frameworks for understanding your actual fitness is Ollie Glaspool's VDOT system (popularized by Jack Daniels).

VDOT estimates your VO2 max equivalent based on your recent race performance. It's not a measure of how hard you're trying. It's a measure of what your body can actually do.

My VDOT in mid-2025 was 39.4. This translates to these training paces:

• Easy (Zone 2) = Pace 6:11–6:47/km, HR 140–155 bpm
• Threshold/Tempo = Pace 5:09/km, 165–180 bpm
• Interval (VO2 max) = Pace 4:45/km, HR 180–195 bpm
• Repetition (Speed) = Pace 4:30/km, HR 190–199 bpm

These aren't aspirational. These are based on my actual recent 5K trial performance.

Why VDOT matters:

Most runners run their easy runs too fast and their hard runs not hard enough. This is because:

• Easy runs feel slow, so they speed them up
• Hard runs are hard, so they don't push as hard as they should

VDOT gives you objective paces. When you run 6:11–6:47/km easy, you're building your aerobic base. When you run 5:09/km tempo, you're training your threshold. When you run 4:45/km intervals, you're training VO2 max.

Running slower or faster than these ranges reduces the effectiveness of the training.

How to calculate your VDOT:

• Do a 5K time trial (all-out effort) or use a recent 5K/10K race time
• Plug it into a VDOT calculator (search "Jack Daniels VDOT calculator")
• Get your estimated VDOT and the training paces that go with it
• Update it every 8–12 weeks as your fitness improves

By mid-2025, my VDOT was 39.4, which is solidly aerobic but not elite. This VDOT tells me I'm capable of running a marathon around 3:52–3:55, a 100K around 22–26 hours, and a 170K around 37–44 hours. This was realistic information for goal-setting.

An injury doesn't appear overnight.

It builds. Slowly. Quietly. Usually while you're ignoring the warning signs.

You feel a twinge. You think, "It's nothing, just a little soreness." You keep training.

Two weeks later, the twinge becomes a persistent ache. You think, "Hmm, I should probably address this." You keep training.

Four weeks later, you can't run at your target pace. You think, "Okay, this is a real problem." You finally see someone.

By then, you've lost 6 weeks to deconditioning because you didn't address it when it was a twinge.

Learning to identify red flags—the early warning signs of injury—is how you stay healthy through 170 kilometers of training.

ASICS Running Club 2024

Cardiovascular and Structural Red Flags

There are two categories of red flags: ones that signal overtraining or inadequate recovery, and ones that signal structural problems.

Overtraining Red Flags:

These are signs that your nervous system is fried, your recovery is insufficient, or your training load is too high:

• Elevated resting heart rate: Your baseline RHR is 58 bpm. If it climbs to 64+ bpm consistently over 3+ days (not just one elevated morning), this signals overtraining.
• Crashed HRV: Your baseline HRV is 39. If it drops below 30 for consecutive days, your nervous system is stressed.
• Persistent fatigue: You feel tired even after rest days. Your legs feel heavy. Your motivation is gone.
• Elevated morning heart rate after hard workouts: After a tempo run, your morning HR should return to baseline within 24 hours. If it's still elevated on the second day, you didn't recover.
• Elevated resting heart rate during runs: Your heart rate during easy runs is creeping up. What used to be 145 bpm now requires 155 bpm to maintain the same pace. This signals fatigue accumulation.
• Sleep disruption: You're lying awake. You're waking up frequently. You're not sleeping deeply even though you have 8 hours in bed.
• Mood changes: You're irritable. You're anxious. You're having trouble concentrating.

When I see 3+ of these signs simultaneously, I immediately reduce training intensity (not volume) and prioritize sleep and recovery.

Structural Red Flags:

These are warning signs that something is biomechanically wrong and injury is developing:

• Pain that appears in the same spot consistently: Sharp pain in your left knee on descents, aching in your right shin on long runs—these are structural problems, not just soreness.
• Pain that gets worse over the course of a run: You feel fine at kilometer 10, but by kilometer 25 the pain is significant. This suggests a mechanical problem that accumulates with volume.
• Asymmetrical pain: One leg hurts, the other doesn't. This suggests either an injury on that side or a compensation pattern.
• Pain that doesn't improve within 2 weeks of rest: Normal training soreness should resolve with 2–3 days of reduced intensity. If it persists beyond 2 weeks, it's structural.
• Swelling or visible inflammation: Puffiness around your ankle, knee, or hip. Warmth in the joint. Visible bruising.
• Altered running gait: You're limping slightly. You're shifting weight to one side. You're shortening stride on one leg.
• Pain that wakes you at night: Sleep is usually when inflammation decreases. If pain wakes you, the inflammation is significant.

For me, the most relevant red flag is right plantar fasciitis. I experienced this after the BDG Ultra 64K in 2024, when I ran macadam downhills. The repetitive impact on descent caused heel pain.

My approach to this vulnerability:

When I feel even mild heel pain, I:

1. Reduce impact volume (fewer long runs on hard surfaces)
2. Focus on technical trail running (softer landings, better technique)
3. Do calf stretches and plantar fascia release work
4. Ice if needed

When I see structural red flags, I immediately:

1. Stop running if pain is sharp or worsening
2. Reduce volume if pain is stable but present
3. Get professional assessment if pain persists beyond 2 weeks
4. Follow rehab protocol precisely

I don't ignore it. I don't "run through it." I acknowledge it and adapt my training.

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.

Pocari Sweat Pacers & Sport Science Team 2024

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.