Before you read your first athlete data you need to know what each metric is actually telling you. This is your plain-English reference guide to the seven core metrics in Soma Analytics and how to read them.
Read it once to build your foundation. Come back to it whenever you need a reminder.
Reaction Time (RT)
Lower is better. Measured in milliseconds.
How fast the brain detects something and sends a signal to respond. The lower the number, the faster the brain is processing.
A rising RT across sessions is one of the clearest signals that the brain needs rest or reduced load. In sport, a fraction of a second changes everything. When reaction time rises, decisions arrive too late. Always compare RT against this athlete's own baseline rather than against fixed numbers. What counts as fast or slow depends on the task and the individual. A simple reaction task will produce much lower RT than a complex choice reaction task.
Accuracy (ACC)
Higher is better. Measured as a percentage.
The percentage of correct responses during the session. It shows how precisely the brain is making decisions under today's conditions.
Speed is only useful if the decisions are right. When accuracy drops the brain is making errors even if it still feels fast. In competition those errors cost points. A stable, high accuracy score means the brain is executing cleanly. Falling accuracy means mental fatigue or overload is starting to affect decision quality.
Variation (CV)
Lower is better. Measured as a percentage.
How consistent the response times are across the session. A low percentage means responses are reliable and repeatable. A high percentage means some responses are fast and others are slow.
A consistent brain is a reliable brain. When variation rises, performance becomes unpredictable moment to moment. A fast mean RT with high CV is not controlled performance. It is inconsistency hiding behind a good average. Always read RT and CV together.
Rate Correct Score (RCS)
Higher is better. Measured as correct responses per second.
A single number combining speed and accuracy together. It rewards responses that are both fast and correct and penalises anything that is slow or wrong. RCS is the most complete summary of how the brain performed in a session.
If you want one number to summarise overall cognitive performance across a block, use RCS. A rising RCS across the block means the programme is working. A flat or falling RCS means something needs to change.
Speed (SPD)
Higher is better. Calculated as 1000 divided by RT.
Speed is a transformation of Reaction Time that makes small improvements more visible. If an athlete responds in 250ms their Speed is 4.0. If they respond in 500ms their Speed is 2.0. Higher Speed always means faster processing. Think of RT as a stopwatch where lower is better, and Speed as a speedometer where higher is better.
Because Speed is more sensitive to outliers than RT, large differences between the two metrics usually mean there are very fast or very slow individual responses pulling the data. Variation will usually confirm this. Never read Speed alone. Always compare it with RT and Accuracy.
RMSSD
Higher is better. Measured in milliseconds. Requires a Polar H10.
A measure of heart rate variability that looks at the tiny differences in time between each heartbeat. The higher the number, the more recovered and adaptable the nervous system is right now. RMSSD is the daily readiness signal. It tells you whether to push or protect today.
A high RMSSD means the nervous system is recovered and ready to take on load. A low RMSSD means it has not recovered from what came before. Pushing hard on a low RMSSD increases injury risk and reduces performance. Check it before every session.
SDNN
Higher is better. Measured in milliseconds. Requires a Polar H10.
A broader measure of heart rate variability that reflects overall nervous system adaptability across a longer window. Where RMSSD changes day to day, SDNN tells you about the bigger picture across the week and the block.
Think of SDNN like a battery. A high number means the nervous system is flexible and adapting well to changing demands. A low number means it is rigid and struggling. A persistently low SDNN across a week is a clear signal that accumulated load has become too much and the programme needs to be reviewed.
Mean vs Minute on Minute
Every metric can be viewed in two ways. Both matter. They answer different questions.
Mean is the average across all responses in the session. It tells you what happened overall. Start here every time you review a session.
Minute on Minute (MoM) shows how each metric changed across each minute of the session. It tells you how it happened. A mean that looks fine can hide a second half collapse that the average absorbed. MoM catches the difference.
Always start with Mean for the overall read. Then open MoM on any task where the result looks interesting, unexpectedly good, unexpectedly bad, or just different from what you expected. MoM will usually tell you why.
Why this matters
You do not need to memorise all seven right now. You need to know they exist, which direction each one should move in, and where to come back when you need a reminder. This article is your reference. Bookmark it and let fluency build over time.