READINESS VERSUS HEART RATE VARIABILITY (HRV)

Your personal stress and recovery equation is unique. It’s not only what you do during training and how your body responds that counts. Work stress, sleep quality, alcohol intake and diet all impact your body’s ability to handle different levels of training load on any given day. Readiness and HRV readouts both attempt to quantify this, but there are crucial differences to how they work and how to apply the insights served up. “HRV reflects your physiological responses to all stressors, not just training stress,” says Marco Altini, data scientist and founder of HRV4Training. “Tracking it allows us to better understand our own response to training and lifestyle stressors, so that we can make meaningful adjustments towards improved health and performance. “In an ideal situation, in which you are responding and adapting well to training (and other stressors), HRV should be stable. Rather than a ‘higher value’, this reflects a positive response to training and lifestyle stressors currently present in our life. Most importantly, a positive response does not mean ‘train hard every day’, rather to ‘proceed as planned’ with your training plan. “Readiness, on the other hand, tries to include various aspects of your life (activity, sleep, HRV etc.) into one digestible score, so that the app can do the decision-making for you. It’s easier for those who don’t have a coach (or the time or knowledge) to look at a cumulative readiness score than it is to interpret the raw physiological heart rate and HRV data.” Because it estimates the effect of things like activity and ‘sleep quality’ on recovery, readiness has inherent limitations. “The reality, of course, is that these things can never be 100 per cent accurate,” says Altini. “Even in an ideal world where activity, sleep and other parameters are correctly quantified, there are so many other factors that will have an impact beyond what a wearable can measure (environmental factors, medication, diet, personal relationships and global pandemics, to name a few). “From this point of view, it might be more helpful to look at the actual physiological data, such as HRV, as an overall marker of your stress response. After all, if any of the factors included in readiness scores (sleep, activity etc.) were suboptimal and affected you negatively, they would already be reflected in your HRV.”