A kettlebell coach on your phone.
BellSense gives you the program, you log the work, and the next session adapts to what you actually did. 10+ free programs, progression that tells you when to add weight, and a readiness read from Apple Health. No sensor required.
Pick a program.
Start training.
Download the app, pick a program, and BellSense lays out every session. All of this runs on your phone alone.
Pick a program
10+ free programs, from beginner kettlebell foundations to advanced power work, and 20+ with BellSense+. Each session tells you the movement, the rounds and the rest.
Train it and log it
Run the session on the app's timers. Log each set and rate how it felt. That rating is a signal, not a diary entry.
It decides what's next
BellSense reads your results and your recovery, then makes the call a coach would make: add, hold, or back off. Not a calendar.
The more it knows,
the better the call.
Four levels of telling the coach what happened. Three of them are in the app today and cost nothing. Start at level one and add what you have.
- Level 1 Free · in the app now
What you log
Sets, reps, the weight, and how hard each round felt. That alone is enough for the coach to make the call: add weight, hold, or back off.
- Level 2 Free · in the app now
Apple Health
Sleep, resting heart rate and HRV, each compared against your own trailing baseline. Three quarters of your daily readiness score is decided before you wake up.
- Level 3 Free · in the app now
A heart rate strap
What your heart did during the set: drift through the session, and how fast you recover between rounds. You can finish every prescribed rep and still be told to hold.
- Level 4 In development
The bell sensor
A sensor that mounts on the kettlebell and measures every rep: verified counts, how much speed you lost across the set, how close you got to failure. Not for sale yet, and the app never requires one.
Most sessions
are a guess.
You like the kettlebell, but you're winging it. Random sessions, no real plan, and no way to tell if any of it is working.
No real plan
You show up and improvise. Some days are hard, some are easy, and none of them build on the last.
No idea when to progress
Add weight? Swap the exercise? Back off for a week? You're guessing, because nothing is keeping score.
No proof it's working
Feeling tired is not the same as getting better. Without a number, last month and this month look the same.
Add, hold,
or back off.
A logbook stores what you did. This decides what you do next. BellSense weighs your results against your recovery and makes one call per lift, then tells you which signals drove it.
- Progression decided by your results, not a calendar
- Every signal compares you to you, never to a population
- Ask it what to train and it picks one session, with its reasoning
- Every prescribed round completed
- You rated the last two sessions easier than the target
- Sleep and HRV are above your own baseline
Built around
the work itself.
No feed to scroll and no rings to close. Just your training, your numbers, and the trend over time.
Scroll to explore the app
The sensor
for the bell.
BellSense started as a small sensor that mounts on the kettlebell just under the handle and streams motion to your iPhone at 208 Hz. It is not for sale yet, and the app does not need it.
When it ships, the same coach runs on measured reps instead of logged ones: verified rep counts, how much speed you lost across a set, and how close you were to failure. That is also where BellScore comes from, a single number for a session the app could actually measure. Speed and power are reported as relative indices, not lab-grade numbers.
Waitlist only. Nothing to pay, and no date promised.
The work is yours.
The standard is shared.
Bring your training partners into a group and measure against the same numbers. Just the work, ranked.
Leaderboards
Honest BellScores, ranked weekly and all-time. Everyone held to the same standard.
Friend groups
A private feed of your partners' sessions. See the work, not a highlight reel.
Shared tests
Run the same benchmark as your group and find out where you actually stand.
On the bell,
not your wrist.
A wrist wearable measures your whole body, a little of everything. BellSense sits on the kettlebell and measures the lift itself: the reps, the speed, and the fatigue in the set.
Tracks your day. Steps, heart rate, sleep. It notices that you worked out.
Coaches the lift. Reps, speed and fatigue, read off the bell, used to tell you what to do next.
A training tool, not a medical device. Built to make you better and show the trend.
Built for people who
want to train well.
If you want to train the kettlebell well and actually know it's working, this is for you.
You own a bell and want a plan
You've got a kettlebell and you're tired of guessing. You want a coach to tell you what to do with it.
You're new to the kettlebell
You're drawn to it, but the internet is noise. You want a clear path from wherever you're starting.
You want proof it's working
Feeling tired isn't the goal. You want to watch your reps get faster and your weight go up.
Not a do-everything wearable
You don't want one more watch that measures running, lifting and sleep, all of it roughly. You want the kettlebell done right.
How we think
about training.
The reasoning behind what the coach does, written out. No sign-in, no email required.
The S-Curve: Why You Finish the Year Where You Started
Nobody adds sixty pounds a year, even though the math says five a month should be easy. Here's where it actually goes, and why your own sense of how it's going is the least reliable instrument in the room.
ReadThe Gray Zone: Too Hard to Recover From, Too Easy to Build Anything
Runners named this decades ago and called it junk miles. The kettlebell version is more common, harder to see, and it feels better than the training that actually works.
ReadHardstyle Drift: Why Your Swings Stopped Building Anything
The better you get at the kettlebell swing, the less the same session trains you. We call that hardstyle drift. Here's the physiology, and how to reverse it.
ReadYou Can Do It All in One Session. It Just Won't Progress You.
The plan that tries to build strength and conditioning in the same movement builds a modest amount of neither. Wanting both isn't the mistake. Merging them every session is.
ReadWhy BellSense Will Make You Better
BellSense is a coach that watches your training through the bell. Here's what it sees, why the change between sessions matters more than any single number, and how that makes you better.
ReadPhilosophy
BellSense's training philosophy: quality reps, intentional effort, and the principles behind every session.
Read
Make every rep matter.
Download it, pick a program, and train tonight. The coaching gets sharper the more you give it.