Keeping Your Finger On The Pulse Of Your Team – Part 2: Heart Rate Variability and Fatigue Guide
In the second part of our blog series looking at heart rate, we cover heart rate variability (HRV), how it is linked to fatigue, and why you should monitor the HRV levels of your team. Read on to find out more about how physiological indicators can reveal fatigue and stress levels within your workforce, enhancing the health and safety and performance of your team.
HRV is an analysis of the time, measured in milliseconds, between each heartbeat. HRV is controlled by the autonomic nervous system (ANS). High variability shows that your body is able to dynamically respond to its environment and its internal conditions. It is when there is very little to no variation in the time between beats, that we should be concerned. Low variability indicates that this system is operating like a metronome – doing the same thing repeatedly, unable to deal with any sudden changes. In this situation, the body may be fatigued or under significant stress, which stops the ANS functioning as well as it might.
Bodytrak broadly categorises two kinds of fatigue: fatigue caused by monotonous work and fatigue caused by significant mental exertion.
Imagine, a lorry driver travelling along long straight roads at the same speed, for hundreds of miles. Now consider a lorry driver negotiating the tight turns, pedestrians, cyclists, and traffic of a busy city, where they must be always alert and responsive. The drivers are under different kinds of mental strain, however they can both exhibit symptoms of fatigue.
This example shows how different types of fatigue can exist within the same industry and the importance of a solution that can detect physiological responses in different scenarios.
Simply put heart rate variability is used to help measure fatigue. This is explained in greater detail below.
We analyse the time between each heartbeat to develop the Bodytrak fatigue score. The fatigue score is measured on a scale from 0 to 5 and shows any abnormalities compared to the individual’s normal heart rate variability levels.
By analysing hundreds of hours of data we can determine what a ‘normal’ HR level is for a specific person and highlight when their HRV is outside of this range. Levels outside of the ‘normal’ range can be markers of fatigue, stress or tiredness.
Low HRV indicates issues with the autonomic nervous system and stress associated with mental or physical fatigue.
Being in a stressed or fatigued state for a prolonged period also impacts cognitive performance, such as reaction time, reduces productivity, increases the risk of accidents, and can lead to ill health. Research shows that poor HRV is associated with increased risk of cardiovascular disease.
What actions should health and safety officers take if the heart rate variability of their employees hits certain thresholds?
If anyone feels fatigued or drowsy, they should rest to allow their body to recover.
Bodytrak’s fatigue score is the product of data-driven insights: real-time data is gathered to understand the baseline for a particular individual enabling the technology to discern when they are not functioning as expected.
The solution is easy to set up, it can be used in various situations, and it doesn’t require excessive interference which other methods rely on – whether this is through external cameras or constant questioning.
Alternative methods, such as video recording and questionnaires can be unreliable and impractical in many industries. Excessive blinking, for example, could indicate fatigue, or it could be a sign of other eye disorders. Questioning employees is unlikely to yield the same quality of results that heart rate analysis can give. Questionnaires are often subjective and participants may not be forthcoming.
To learn more about how Bodytrak can help you manage the health and safety of your team, book a demo today.