Home / Exercise guides / Side Lunge rep counter

Side Lunge Rep Counter

Skip the mental math. Point your phone at yourself and every full-range side lunge counts itself — sets, reps, and PRs logged while you train your quads and glutes, with hamstrings and calves assisting. Free in your browser today; coming to Google Play and the App Store.

Coming to Google Play & the App Store▶  Try The Rep Counter
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SIDE LUNGES7/ 10
Live screen in miniature — the app’s real side lunge demo (front view), with the rep counter, form bar, and phase dot. On-device.
Straight From The App

HOW TO DO A PROPER SIDE LUNGE

Setup  Face the camera, feet wide, toes pointing forward.

  1. Shift your weight to one side, bending that knee and pushing your hips back.
  2. Keep the other leg straight and both feet flat.
  3. Push back to center and switch sides.
Form cue: Push knee out wide

Same sheet as the ⓘ panel in the app — animated demo included.

How The Counting Works

HANDS-FREE IN THREE STEPS

1

Prop your phone and get in frame

Phone at roughly torso height, stand facing the camera. A quick camera test checks lighting, distance, and angle before you start.

2

The camera locks a 17-point skeleton on you

GOODREPS measures your knee angle (hip → knee → ankle) on-device — no wearables, no clickers. Bodyweight or a single kettlebell/dumbbell held at the chest.

3

Just work — the counter does the counting

A rep banks at the bottom (~100°) and re-arms near ~160°. Half reps don’t count; after 3 clean reps it calibrates to your range.

Under The Hood

WHAT MAKES A REP COUNT

Form Still Matters

COMMON SIDE LUNGE MISTAKES

Letting the knee cave inward

Track the working knee over the middle toes as you sit into the hip.

Trailing foot peeling and twisting

Keep the long-leg foot flat and pointed forward unless the app cues otherwise.

Cutting depth

Sit until the working thigh gets near parallel if your hips allow — shallow reps hide.

Rounding forward

Hinge the hips back with a proud chest. The camera sees a collapsed torso.

Your Data

PRIVATE BY DESIGN

Rep counting runs entirely on your device — your camera feed is never uploaded.

Pose detection runs in your browser via TensorFlow.js. Camera frames are analyzed in real time and immediately discarded — nothing is recorded, nothing leaves your phone, and we never see them. Sign-in is optional; skip it and everything stays local.

FAQ

QUESTIONS, ANSWERED

Do I need any equipment to check my side lunge form?

Just your phone for most variations. Add free weights when the pattern is clean — the app still scores the movement either way.

Does it work in a home gym or low light?

Run the built-in camera test first — it checks your lighting, distance, and angle with live green checks before you start. If a rep still slips through, manual counting is always one tap away.

Is my camera feed uploaded anywhere?

No. Pose detection runs entirely on your phone, in your browser. Frames are analyzed in real time and immediately discarded — nothing is recorded, nothing is uploaded.

Keep Going

RELATED GUIDES

Coming to Google Play & the App Store▶  Try GOODREPS Free

Free forever — camera counting for all 60 exercises, no account needed. Pro (voice coaching, programs, depth-camera form checks) is $7/mo, $49/yr, or $99 once. No ads, ever.