Muay Thai Heavy Bag Workouts

Muay Thai classes for your heavy bag, with your phone strapped to it. Kai Muay calls every round like a coach, counts and measures every strike — punches, kicks, knees and elbows — and tells you at the end whether you passed the class. No sensors to buy, nothing to wear: the phone you already have does the job.

WHO IT'S FOR
Anyone who trains Muay Thai (Thai boxing) and has a heavy bag or punch bag to hit: at home, in the garage, or at the gym on days when there's no class. And anyone who has just put up a punching bag and doesn't know where to start: the Base level begins with the stance, the jab and the cross, and it's free. No bag yet? The same classes work as shadowboxing.

ON THE BAG, NOT ON YOUR WRIST
Kai Muay puts nothing on your wrist, where a sensor would have to guess the strike from how your hand moves. Your phone sits on the bag and reads the impact where it lands: the voice calls the strike and the bag says whether it landed. The phone measures how many of the called strikes landed, how far you drifted off the beat, your cadence, and how hard you hit, in g. Kicks and knees included.

REAL MUAY THAI
A practitioner's curriculum, not a list of exercises: 37 techniques, each with its Thai name, key points, common mistakes and how to fix them, and a video from the front and from both sides. Then 32 classes and 136 combos to put them to work.

HOW IT WORKS
1. Mount the phone on the heavy bag, above where you strike, with a strap or a running armband. You hit below it, never on it. An old phone works fine.
2. Pick a class. The coach's voice calls every round: the combos, the pace, when to rest.
3. Hit the bag. Every strike is counted and measured, and when the class is over you know whether you passed.

THE PATH
Each class is a complete Muay Thai workout, not a string of rounds: technique, warm-up, jump rope, shadowboxing, called rounds on the bag, free rounds, and conditioning to finish. Every round works two combos: the first in minute one, the second in minute two, and both chained together in minute three. The Base level — 3 classes, from the stance to the hook — is free. Beginner, Intermediate, Advanced and Defense (28 more classes) unlock with a subscription.

YOUR GRADE
Strikes landed, consistency, cadence and power — by round, by side, by strike family and by technique — plus how long each combo took compared with last time. The bag decides your grade on two numbers, landed and consistency, and a single miss won't fail you. Repeat a class and your best session is the one that counts. The Progress screen shows whether you're improving: your consistency baseline, strikes by family, where in the combo you tend to miss, and your week streak.

TRAIN YOUR OWN WAY
A round timer with the rounds you choose, a jump rope mode that counts your jumps and sets, freestyle — no script, every strike still measured — and combo routines of your own: pick them from the library, build them strike by strike, or let the app draw them at random. Southpaw? Every call is mirrored. And flexibility: three routines of nine stretches for legs, hips and back, at the end of a class or on their own.

NO ACCOUNT, NO ADS
No account, no server of our own, no ads. You train offline; only each level's videos download once, the first time you open it. What the phone measures stays on the phone: the only things that leave are what you export yourself and anonymous usage statistics, which you can turn off in Settings. Purchases are handled by Google Play.

FREE TO START
Free, with every strike measured: the Base level, the round timer, jump rope, freestyle, the after-class stretches, your history, and combos and routines built on the Base techniques. No ads. The full Path and the other two stretching routines come with a subscription — yearly or monthly — or with a one-time lifetime purchase.

All you need is a phone with an accelerometer, which any recent Android phone has: the one in your pocket or the old one in a drawer. Nothing else to buy.