Recovery calculator
Orthostatic test calculator
Take your heart rate lying down and again after standing, and read the rise against the published postural tachycardia threshold for your age. Free, instant, no sign-up.
- The rise has to be sustained through ten minutes of standing or head-up tilt, not caught at one moment.
- It has to come with orthostatic symptoms. Tachycardia without them is not the syndrome.
- Symptoms have to have persisted for months, not appeared this week.
- It has to occur without a sustained fall in blood pressure. A rise with one is a different diagnosis.
- Everything else that raises standing heart rate has to be excluded: dehydration, fever, anaemia, prolonged bed rest, medication, thyroid disease.
One morning's delta means little. The coach reads it against the training week that produced it.
What the test measures
Standing drops several hundred millilitres of blood into the legs. The heart rate rises to defend cardiac output, and how much it rises is the measurement. That is the whole test: one reading lying down, one reading standing, and the difference between them.
The two published thresholds
The 2011 consensus statement (Freeman et al., Clin Auton Res 21:69-72, carried forward by the 2015 Heart Rhythm Society expert consensus statement) puts the postural tachycardia line at a sustained rise of at least 30 bpm within ten minutes of standing, and at 40 bpm for adolescents aged 12 to 19. The adolescent figure is not a rounding of the adult one. It is a different criterion for a group whose normal orthostatic response is larger, and applying 30 to a fifteen-year-old flags healthy teenagers. Ages under 12 are refused rather than estimated: the criteria start at 12, a child's normal response is larger again, and there is no published threshold below it.
A criterion is not a diagnosis
Reaching the heart-rate threshold is not a diagnosis and is not close to one. The definition also requires the rise to be sustained across ten minutes, to come with orthostatic symptoms, to have persisted for months, to occur without a sustained blood-pressure fall, and to survive exclusion of everything else that raises standing heart rate. This calculator can evaluate exactly one of those clauses, which is why the other five ship alongside the number rather than in small print underneath it. If the threshold is met and any of that sounds like you, the next step is a doctor, not another measurement.
The same measurement for training monitoring
Athletes use this as the Rusko orthostatic test, tracking the delta morning to morning: a rise above your own usual range suggests recovery is incomplete. No absolute recovered / not-recovered cutoffs are returned for that use, because none are published — Rusko's own interpretation is against personal baselines. So the useful comparison is not today's number against a table, it is today's number against your own last two weeks.
How to take the measurement
The protocol matters more here than in most tests, because the whole result is a difference between two numbers taken minutes apart. Lie down and stay still for at least five minutes — ten if you can — then record your heart rate while still lying. Stand up in one movement and stand still, without leaning on anything, then record again. Take the standing reading at the same point every time you do this: one minute is the usual clinical choice, and for training monitoring the Finnish orthostatic protocol reads it after about ninety seconds. Whichever you pick, keep it identical between sessions. Do it first thing, before coffee, before food, and after emptying your bladder — a full bladder alone shifts the response. Two people using different timings are not running the same test, and neither is you on two different mornings.
What this calculator does with your numbers
Standing minus lying, and the age picks which published line the difference is read against. A negative delta comes back as measured rather than rounded up to zero. That is all of it — a threshold comparison on one pair of readings, which is a much smaller thing than the threshold's clinical context makes it sound.