Free tool
Strength Readiness Calculator
Use HRV, resting heart rate, sleep, soreness, RPE, recent training, and planned intensity to decide how to adjust today's strength session.
The Tuwa strength readiness calculator uses HRV and resting heart rate changes, sleep, soreness, recent training frequency, planned intensity, and session type to suggest whether to push, maintain, reduce volume, swap intensity, or recover. It is a training planning aid, not medical advice.
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Calculator
Estimate today's session adjustment
Fill in the signals you already have. The result is a training prompt, not a diagnosis or medical recommendation.
Key takeaways
What matters for this decision
- Readiness should change the session prescription, not just label your day as green or red.
- The most useful adjustment is often volume or RPE, not a full rest day.
- Use the result as a coaching prompt and keep pain, illness, and medical concerns outside the calculator.
Decision rules
If this, change that
- If HRV is lower than baseline and RHR is higher than baseline.
- Keep the main lift technical, cap RPE, and reduce accessory volume.
- If Sleep is poor and soreness is high before a heavy lower-body day.
- Swap max intensity for technique work or reduce the planned session.
- If Recovery signals are normal and recent load is not spiking.
- Maintain or push the planned session if warmups confirm readiness.
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Inputs the calculator uses
- HRV compared with your normal baseline.
- Resting heart rate compared with your normal baseline.
- Sleep duration and quality.
- Soreness level before the session.
- How many hard training days you have stacked recently.
- The planned intensity and whether the session is strength, hypertrophy, hybrid, or conditioning.
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How to interpret the output
| Output | What it means | Typical adjustment |
|---|---|---|
| Push | Signals support the plan and recent load is manageable. | Keep the plan; add load only if warmups move well. |
| Maintain | Signals are mixed but not clearly poor. | Run the plan with normal rest and honest RPE caps. |
| Reduce | Recovery or soreness suggests less total work. | Cut 20-40% of accessory volume or back-off sets. |
| Swap | Intensity is the issue more than movement. | Keep skill practice; swap heavy work for technique or tempo. |
| Recover | Multiple red flags stack together. | Choose mobility, easy aerobic work, or full rest. |
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What Tuwa automates
The calculator is a standalone tool. Tuwa makes the same decision loop easier by pulling Apple Health recovery signals, keeping the workout log, tracking workload, and saving the weekly review in one place.
The point is not to outsource judgment. The point is to make the relevant signals visible before you add load, chase a PR, or stack another hard session onto a tired week.
FAQ
Common questions
Is a low readiness result a reason to skip training?
Not always. A low result usually means you should adjust the session. Reducing accessory volume, capping RPE, or swapping intensity can preserve practice while lowering strain.
Can this calculator diagnose overtraining or injury risk?
No. It is not a medical or diagnostic tool. It is a training-planning prompt that combines recovery and workload context.
Why include soreness and RPE if Apple Watch already has recovery data?
Strength training needs local context. HRV and sleep do not know whether your quads are sore, your top set overshot RPE, or your planned day is heavy squats.
Sources
References and related pages
Sources
Want this decision loop inside your training log?
Tuwa combines Apple Watch recovery signals, workload, soreness, RPE, and workout history so today's adjustment is tied to the actual session.