100-mile ultramarathon

Heart Rate Variability (HRV) and overall fitness

Heart Rate Variability (HRV) and overall fitness

Elite point of view

Have you ever wondered how a stressful day can impact your health? People often assume that the biggest effect stress has on you is on your mind. However, recent studies have shown that it can have an impact on your physical health too. Monitoring your Heart Rate Variability (HRV) may be the piece of data that could help reduce the impact. A stressful day could affect your workouts and exercise for up to several days after. Therefore, we should be thinking ahead. For example, if there’s anything you can do today that would improve your ability to perform better physically tomorrow this would decrease the knock on effect that stress and negativity can have on your week moving forward.

Heart Rate Variability is a measure of the variation in the time interval between heart beats. Measuring HRV is important because it gives you an indication of how your automatic nervous system (ANS) is doing. The ANS regulates certain body processes, such as blood pressure and the rate of breathing. The healthier the ANS the faster you are able to switch gears, showing more resilience and flexibility, therefore, the higher the HRV the better.

A high HRV is associated with general fitness and sufficient recovery, and a low HRV is associated with too much stress or overtraining. A low HRV can be a sign that your body is spending too much time in a heightened state of stress. Studies show that a low heart rate variability could result in an increased risk of diabetes, high blood pressure and cardiovascular disease. While that doesn’t mean that a low HRV causes these issues, it might be an indication that certain lifestyle choices (alcohol consumption, poor diet, lack of sleep, etc.) play a role in increasing the risk factors for such health issues.

The most effective way to improve your HRV is through regular exercise a few times per week. While exercise is a stressor, it helps the body to repair, adapt and come out stronger on the other side. That adaptation is what improves your response to physical stimuli, leading to an increased HRV. Typically it should take 30-60 days until you see an increase. Types of exercises that can aid in increasing HRV are; long distance walking, high-intensity workouts such as CrossFit, lifting heavier weights, meditation and taking part in yoga and pilates, however, any type of regular exercise can lead to an increase in HRV. We have workouts and programmes available for you to achieve this. However, don’t forget you can implement other tactics into your daily routine to increase HRV such as, controlling your mental stress, eating a healthy balanced diet, getting a good sleep and getting outdoors.

Although tracking HRV can’t help you avoid stress all together it can help you to understand how to respond to stress in a healthier way. This can help create more awareness of how you live and think and how your behaviour can affect your nervous system and bodily functions. It is intriguing to see how HRV changes as you merge more mindfulness, meditation, sleep, and especially physical activity into your life. Why not give it try? Many modern fitness watches such as Apple watches can track your HRV. Third party apps and devices can also track HRV such as the health app found on iPhones. Next time you’re training in the gym or taking part in a class, why not track your workout and monitor your HRV throughout the session.

Summary of Study – “Influence of a 100-mile ultramarathon on heart rate and heart rate variability”

In recent years, when it comes to endurance sports, the heart rate variability (HRV) has been prioritised in order to enhance the timing and intensity of training for maximum preparation for competition. Studies show that HRV could be a the way to evaluate recovery.  HR is controlled by the Autonomic nervous system (ANS). The ANS is divided into two , the sympathetic (SN) and the parasympathetic nervous system (PNS),  also known as the fight-or-flight mechanism and the relaxation response.

Persistent instigators such as stress, poor sleep, unhealthy diet, dysfunctional relationships, isolation, and lack of exercise can disrupt the balance between the SN and PNS and your fight-or-flight response can shift into overdrive.  If a person’s system is in fight-or-flight mode more often, the variation between subsequent heartbeats is low. If one is in a more relaxed state, the variation between beats is high.


This study aimed to investigate the impact of an ultramarathon with a distance of 100miles on heart rate (HR) and HRV. 28 runners underwent 24-hour Holter ECG monitoring 1 week before the ultramarathon, immediately after the ultramarathon and after a week of recovery. The influence of HR and HRV on the run time and recovery was investigated.

The present results show that a 100-mile run leads to an increase in sympathetic activity and thus to an increase in HR and a decrease in HRV. These results show that during a ultramarathon influences such as fatigue and exhaustion occur and lead to a reduction in the athletes HRV, this is turn affects their recovery time post event.  Heart rateThis can be dangerous to an athlete, firstly because long periods of recovery time can  lead to training reversibility. Additionally, previous research has shown a low HRV is associated with worsening of depression or anxiety as well as an increased risk of cardiovascular disease and death. Therefore appropriate and adequate training must take place to increase an athletes HRV.

Research shows that regular endurance training leads to an increase in HRV and people who have a high HRV may have greater cardiovascular fitness and be more resilient to stress.  Through measuring these variables the results showed that the HR and HRV values are useful to evaluate recovery after such an extreme exertion as an ultramarathon.

These findings will allow athletes to establish new training possibilities for endurance sports.  HRV can also provide personal feedback about your lifestyle and help motivate those who are considering taking steps toward a healthier life.

If you would like to read the full article click the link below:

Paech CSchrieber SDaehnert I, et al

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