Summary
- Tensr is for precision training in the zone. With a compatible sensor, follow external tension through the set, then review the recording afterward.
- Strong is a great between-set logger. If you want to stop, enter your weight and reps, and get back to lifting, it does that job well.
- Your Tensr data stays yours. Local history and open exports let you keep your records and take them to other tools, without a subscription.
- Work with your own agents. Use exported training data and editable workout files with an AI tool you choose.
- Start Free Forever. Recording, planning, local history, and exports are free. Paid services are coming later; upgrade when they make sense for you.
- Strong import is planned. Bringing your Strong CSV history into Tensr is on the roadmap; it is not available yet.
Strong is a fantastic replacement for a training notebook. Enter the weight and reps between sets, and the record is there next time you train. A whiteboard is paperless too; Strong adds the charts, personal records, and estimated one-rep max (1RM) that a whiteboard will not calculate for you. Strong’s App Store listing
It is one of the best apps for recording weight × reps. It also supports supersets, RPE, timers, and CSV export. Strong is available on iPhone, Android, and Apple Watch. Tensr’s native app is currently iOS, alongside a browser app; there is no native Android app yet. Strong’s feature overview
Strong has a free version. For Pro, its U.S. App Store listing includes $29.99/year and a $99.99 one-time Strong PRO Forever purchase. Prices and offers can vary by region. That is roughly $30 a year or $100 once; check the offer shown in your app before purchasing. Strong’s listed purchases
The question for someone already using Strong is what a force sensor adds. A set entry preserves what you logged. A compatible sensor can also preserve what happened to external tension while you were doing it.
Same load. Same distance. Different time under load.
Think about a farmer’s carry. Pick up the same two weights and walk the same 20 metres, once in 20 seconds and once in 40. The load and distance entries match. Your grip has still spent twice as long holding the weights on the second trip.
That does not make the two carries physiologically identical except for time. Speed, stride, and stabilization change the task too. Research on loaded walking has measured changes in joint work and power with walking speed. Lenton et al., 2019
The carry is an illustration of what a short log entry leaves out. Tensr’s inline sensor does not directly measure an ordinary dumbbell farmer’s carry. But on a suitable cable or band setup, it can record external tension through the set, rather than leaving the whole story at weight × reps.
A logged set and a measured curve answer different questions
Finish three sets of cable rows and enter the load and twelve reps per set. That gives a logger useful information: which movement you trained, the load you recorded, and how many repetitions you completed. Charts and calculated estimates can make that record more useful.
Those entries do not supply a sample-by-sample force trace. They cannot show whether external tension stayed steady, fell between repetitions, or differed between separately recorded left and right sets.
Strong also calculates summaries and can integrate other data. Logging load and reps still does not measure the force applied throughout the set.
Where the sensor can actually go
A Tensr-compatible tension sensor needs a place in the load path, so the force being applied passes through it. A suitable cable, band, suspension, or hangboard setup can provide one. The attachment and movement determine whether that arrangement is practical.
Our inline tension-sensor approach does not directly measure an ordinary barbell squat, bench press, or deadlift. It does not gain that ability because the movement appears in the catalog.
| Your setup | What Tensr can add |
|---|---|
| Compatible inline tension sensor | A recording of the force at that sensor |
| Ordinary free-weight lift | A logged record; an estimate remains an estimate |
| No connected sensor | No measured force trace |
The sensor measures external tension at its attachment. It does not directly measure muscle force, muscle growth, or movement quality. A force curve also does not become a velocity measurement without additional information.
If your training is mostly free weights and Strong already fits your routine, there is little reason to switch just because Tensr supports a force sensor.
What recording the force can add
Cable and band work give the measurement layer a more useful job. A stack’s pin number or a band’s color describes the setup, but neither tells you the full force history during a repetition.
With a suitable recording, you can inspect how tension changes through a set and compare traces from repeated attempts. Force integrated over time gives impulse: a description of external force sustained over the recorded interval. It adds information to load and rep count without being a complete measure of training stimulus.
Those comparisons need consistent context. Changing the movement, range of motion, pulley arrangement, or sensor position can change what the reading means. A larger impulse across unrelated setups does not establish a better workout.
Left/right comparison likewise requires a recording of each side under comparable conditions. A single sensor on a bilateral cable cannot infer how much each arm contributed.
Sampling and timing matter too. We have documented a packet-timestamp problem in our capture path that affects timing-derived calculations. That limitation belongs in a comparison about measurement: connecting a sensor does not, by itself, validate every metric derived from its readings.
Keep your data and choose your tools
Strong documents CSV export on iOS and Android. Its help center also says those exported files cannot be imported back into Strong. That is a distinction between an export and a restore path, not a reason to claim your history cannot leave the app. Strong’s export documentation
Tensr offers a local SQLite database export. It preserves the application’s stored tables and recordings in a file that other SQLite tools can inspect. The schema and recording formats still need to be understood to interpret the contents. A CSV is usually easier to open in a spreadsheet; a database can retain more of the application’s structure and relationships.
That is our commitment to avoiding lock-in: the local core and exports do not require a subscription. You can hold the file yourself, inspect it, and decide which tools get a copy. Strong’s CSV export is useful too; ownership should be judged by what you can actually take with you.
Importing completed Strong workouts into Tensr is planned, not shipped. Strong’s export gives that work a starting point. We still need to map the history and preview the result before calling it an import feature. A past weight-and-rep entry will remain a logged entry; importing it cannot create a force recording that was never captured.
Let an agent work with your record
You can give an AI tool you choose a Tensr export, ask it to inspect your
training history, and have it help draft a routine in the editable
workout.md format. Our agent setup guide
and workout format documentation
describe that workflow.
For example: ask it to summarize your recent cable-row sessions, show the records behind the comparison, then propose next week’s routine for you to review. The useful part is that the data and the resulting plan are files you can inspect and keep. An agent still needs to respect the recording’s limits; it cannot infer muscle growth or recovery from a force trace alone.
Start Free Forever
Tensr’s recording, planning, local history, and exports work on your device without an account or subscription. A compatible sensor is separate hardware if you want measured force. Optional paid cloud services are coming later; paid signup is not open yet. Start with the free core and upgrade when those services are available and useful to you.
Choose for the work you actually do
If you want a capable set-and-rep log and Strong is already working for you, keep using it. You do not need a sensor to maintain a useful training history.
If you train with a compatible cable, band, suspension, or hangboard setup and want to inspect the force through a set, Tensr adds a different kind of record. You can explore that alongside your existing log rather than rebuilding your whole training habit around it.
Same load. Same distance. Different time under load. The carry reminds us why a brief log entry can leave something useful out. On movements where we can record tension, the question is whether that extra signal changes a training decision you care about.
