The AISRI Index and readiness: two numbers, two questions
By Coach Kura3 min read
Open AKURA and you see two headline numbers: your AISRI Index and today’s readiness. They look alike, both run from 0 to 100, and runners mix them up all the time. They answer different questions, and knowing which is which makes your training easier to trust.
The AISRI Index: how capable a runner are you?
The AISRI Index is a 0 to 100 score of your running capability. It is the headline number of Coach Kura’s method, and it looks at you as a whole runner, not only at your recent running.
It is built from six pillars. Each pillar gets its own score, and the Index is a weighted average of them:
| Pillar | Weight | Where it comes from |
|---|---|---|
| Running performance | 40% | Your last 4 weeks of runs: distance and how often |
| Strength | 15% | Simple self-tests |
| Balance | 13% | Simple self-tests |
| Range of motion | 12% | Simple self-tests |
| Mobility | 10% | Simple self-tests |
| Alignment | 10% | Leg alignment and foot strike, from your intake |
If a pillar has no data yet, AKURA does not guess it. The weights are spread over the pillars you have tested, and new athletes see no score at all until their intake is done and their runs are in.
It moves slowly: the running part follows your last four weeks of runs (how much and how often you run); the other five change when you retest.
Why running is only 40%
Mileage on its own does not make a durable runner. To keep training week after week, your body has to absorb the load: strong enough legs and hips, good balance on one foot, joints that move through their full range, and legs that line up well when you land.
That is why five of the six pillars are about the body that carries the running. A runner who logs 50 km a week but wobbles when balancing on one leg has a clear next step, and the Index shows it.
Readiness: can you train hard today?
Readiness is today’s check. It is worked out every morning from your sleep, your resting heart rate, heart-rate variability where your watch records it, your recent training load and, if you choose to share it, how you feel.
Its job is to decide how hard today should be. On a high-readiness day your planned session stays on. On a low day the hard work is eased back to an easy run, or swapped for rest and light mobility.
When the two numbers disagree
They often do, and that is normal. Two examples:
- A strong runner with a high AISRI Index sleeps badly after a heavy week. Readiness is low, so today is easy. Their capability has not dropped; their body simply needs a lighter day.
- A newer runner with a modest Index wakes up fresh after a rest day. Readiness is high, so the planned session goes ahead, at their level.
Capability tells your coach what you can build towards. Readiness tells you what to do this morning.
Two more numbers you may see
Training load shows your fitness, fatigue and form over the last weeks, from the effort of each run. It is not a 0 to 100 score.
Your TAEI (AKURA Endurance Index) is worked out from your best recent race efforts, and it sets your training paces.
Each of these is a separate number with its own name. If a screen shows a number, it tells you which one it is.
What to do with each number
- AISRI Index: retest when your coach asks, and work on your weakest pillar with them.
- Readiness: connect a phone or watch and it shares your sleep and heart rate, so you fill nothing in. A low number is not a failure; it means take today easier.
- Training load and TAEI: look at the trend over weeks, not a single day.