What she is really measuring

Heart rate variability (HRV) measures the variations in time between each heartbeat. Unlike heart rate, which counts the number of beats per minute, HRV looks at the differences between the intervals.

In practical terms, a heart rate of 60 beats per minute does not tick off one beat every second like a metronome. The intervals vary constantly: 1 s, 0.9 s, 0.8 s, 0.7 s, then 0.8 s, 0.9 s, 1 s, 1.1 s, 1.2 s, and so on. This permanent flexibility of the rhythm, its ability to speed up and then slow down, is precisely what HRV measures.

Why it is important

An indicator of stress and fatigue

HRV helps to assess stress and fatigue levels. Reduced variations can signal that the body is under pressure, whether from physical, mental or emotional stress.

A guide for managing one's recovery

For athletes, HRV is a useful indicator for adjusting recovery periods. By monitoring it, one can better judge whether the body is ready for an intense session or rather needs rest.

A marker also monitored in healthcare

HRV is also used in the medical field to monitor cardiovascular health, with a high HRV generally being associated with good heart condition. This monitoring is the responsibility of healthcare professionals and falls outside the scope of wellbeing.

How to measure it

With a reliable sensor

Polar-type chest straps are the gold standard. Many smartwatches offer an HRV measurement function, which is practical for monitoring one's own trends, even if none are recognised as a scientific validation.

At rest, in the morning

For consistent data, the measurement should be taken in the morning upon waking: approximately 5 minutes lying down, followed by 5 minutes standing beside the bed. This provides stable baseline values.

Regularly

HRV is read over time. By measuring upon waking each day, you track your trends and spot significant variations, which are far more telling than an isolated value.

Use it every day

Planning workouts

By tracking your HRV, you adapt your programme to your recovery state. A fairly high HRV suggests the body is ready for exertion, while a low HRV suggests easing off.

Listen to the trends, not the jolts

A single measurement doesn't say much. It's the trend over several days that makes sense: a sustained drop may suggest slowing down, while a rise indicates resuming gradually.

HRV, sleep and IAKOTA

HRV is closely linked to sleep quality, which is why the benchmark measurement is taken in the morning upon waking. The IAKOTA mattress topper are designed to support your sleep and recovery, by combining the reflection of infrared rays emitted by the body with earthing.

Heart rate variability is a valuable indicator for understanding stress, fatigue and recovery. By integrating it into your routine, you above all learn to listen to yourself better, night after night and session after session.