Running form analysis for marathon runners

Marathon form is not about what you look like at kilometre 5. It is about what you look like at kilometre 35, when the glutes stop firing and the trunk folds. A side-view clip filmed at the end of a long run shows you exactly how your shape drifts. Caden measures that drift, compares it with your fresh form and builds drills around the weakest part.

What marathon form problems usually are

Marathon runners are efficient when fresh. The problems show up with fatigue, and they follow a pattern.

1. Sitting back. The hips drop behind the feet late in a run. The torso leans back or folds forward at the waist to balance. The upper body lean dial catches this as a change in lean angle between fresh and tired.
2. Reaching forward. As the stride shortens from fatigue, many runners reach with the foot to keep pace. The foot lands ahead of the hip with a straighter knee. Cadence drops and the landing gets louder.
3. Less knee bend at midstance. A tired leg stops absorbing. The front knee stays straighter at the moment the body passes over the foot. That sends more of each step into the knee and hip.
4. Arms crossing. Elbows drift wide and hands cross the midline as the shoulders tire. The trunk twists to compensate.

None of these show up on a track at 5K pace. They show up in the last 20 minutes of a 30 kilometre run.

What to film

Film twice on the same day. Once in the first 2 kilometres of a long run. Once in the last 2 kilometres. Same stretch of path, same phone position, same view.

Side view, phone at hip height on a bench or post, 6 to 8 metres from the path. Run past at your marathon effort for 10 to 20 seconds. Do not tidy up for the camera.

A training partner can hold the phone if the height and distance stay the same. See how to film yourself running. If you do most long runs on a treadmill, film beside the belt the same way. Note that treadmill stride is often shorter than road stride, so film outdoors for the real picture.

What Caden shows you

Two form scores, one fresh and one tired. The gap between them is the number to watch. A fresh 84 and a tired 71 tells you more than either number alone.

Six dials per clip. For a marathon runner, the useful ones are:

• Upper body lean. Torso lean in degrees. A jump between the two clips means your trunk is not holding.
• Where your foot lands. Foot landing as a fraction of leg length. A rise in the tired clip means you are reaching to hold pace.
• Knee bend on landing. Flexion at midstance. Less bend when tired means less absorption.
• Cadence. A drop of more than a few steps per minute late in the run is a sign of the stride lengthening.

Breakpoints give you a freeze frame at foot strike, midstance and toe-off for each clip. Put the fresh and tired midstance frames next to each other in Before and after. The skeleton overlay makes the drift plain.

Stats tracks each dial over time, so you can see whether your tired score is closing on your fresh score across a training block.

A sample 4-week plan for a marathon runner

Caden builds a 4 or 8 week plan on the Exercises tab from your lowest dials, three short sessions a week at a session length you choose. Here is a typical one when upper body lean and knee bend on landing are lowest. Ideally do sessions after an easy run so the legs are already a bit tired.

Weeks 1 and 2: build the hold.

• Split squat, 3 × 8 each side. Slow down, drive up.
• Glute bridge, 3 × 12.
• Dead bug, 3 × 8 each side.
• Single-leg balance, 2 × 30 seconds each side, eyes forward.
• On one long run, use the cue for the last 3 kilometres.

Tall hips, quick feet.

Weeks 3 and 4: hold it under fatigue.

• Step-ups, 3 × 10 each side, on a knee-high step.
• Slow calf raises, 3 × 12.
• A-skip, 3 × 20 metres, done at the end of a long run.
• Quick-feet strides, 4 × 20 seconds, at the end of a medium run.
• Hip flexor stretch, 2 × 30 seconds each side, after every long run.

Film fresh and tired again at the end of week 4. The tired score should be closer to the fresh one.

What Caden will not do for a marathon runner

It will not write your training plan or tell you your race pace. It measures form, not fitness.

It will not tell you if a niggle is an injury. Fatigue changes are often linked with knee, hip and calf complaints, but a video cannot tell you the cause. See a clinician if pain lasts.

It cannot see pronation, force or 3D hip rotation. It sees a 2D side view. It cannot tell you about shoes or carbon plates.

How to do it in Caden

1. Open Caden and tap Run a new analysis.
2. Film 10 to 20 seconds in the first 2 kilometres of a long run, phone at hip height 6 to 8 metres away.
3. Film again in the last 2 kilometres from the same spot. Run both at marathon effort.
4. On each results screen, note the score and the Upper body lean, Where your foot lands and Knee bend on landing dials.
5. Open Stats, then Before and after, and compare the two midstance frames.
6. Open the Exercises tab. Do the plan sessions after easy runs so you train the hold when tired.

FAQ

Why does my form break down late in a marathon?

The muscles that hold your hips and trunk tire before your lungs do. The glutes and deep core stop holding the pelvis, the trunk folds, and the stride reaches or shuffles. Strength and drills done on tired legs are the usual fix.

What is efficient marathon form?

Foot landing close under the hip, a small forward lean from the ankles, a relaxed arm swing and a cadence that does not drop late in the run. It looks quiet and repeatable rather than fast.

Should I raise my cadence for a marathon?

Only if your tired clip shows cadence falling and the foot reaching. A 5 percent rise from your current number is enough. Chasing 180 for its own sake makes most marathoners run stiff.

How often should I film during a marathon block?

Once every four weeks, fresh and tired on the same day. Compare tired scores over the block. That trend matters more than any single clip.