BFR and heart rate variability

You’ve got your workout planned. Only something feels different. Usually you can’t wait to attack your reps and dominate your sets. But today it’s as if your body is trying to tell you something.

When it comes to workouts, any one of a number of factors can affect how ready your body is to perform. Perhaps you went too hard the day before, or maybe you’ve been busy at work. It may be down to stress at work, or even just a late night followed by an early start.

It may feel as if your body is trying to tell you something. But it isn’t always easy to know what that something is.

Wouldn’t it be ideal if there was a simple measurement that could sum up exactly how prepared your body is to work out?

Step forward Heart Rate Variability (HRV): our favourite objective measurement of fitness and a great marker for determining general health, stress and recovery.

Heart Rate Variability

HRV measures the variation in time between your heartbeats, which is usually anything from below 20 to over 200 milliseconds. The exact figures are highly individualised and constantly changing, which means that what is considered to be a healthy HRV figure differs between people. When measuring HRV, it is therefore best to compare your results over time and assess your own HRV trends, rather than benchmarking them against someone else’s.

But what do those measurements mean? Well, HRV tells you how your body is balancing the two branches of your autonomic nervous system: sympathetic (increased alertness to activate the ‘fight or flight’ response) and parasympathetic (decreased alertness to return the body to a state of calm). Both of these branches constantly send input to the brain, and when they are balanced the body is perfectly prepared to adapt to its environment: whether that’s running from a bear or lifting a weight. This balance causes fluctuations in heart rate, which then gives a higher HRV score. The higher your HRV score, then, the more balanced these two systems are and the better prepared the body is for exercise.

HRV figures change with factors such as recovery levels, stress, emotions, environment and behaviour. If your figures are lower than normal then it means that one of these factors could be having a big impact on your body. Your nervous system will either be either stressed or fatigued and your body will be suffering, which means it could well be time for a rest.

Understanding HRV and monitoring it regularly is therefore an excellent way to know how your body is feeling, how to respond to stress and how hard to train – if at all.

How BFR Improves HRV

There are numerous ways to tire out the motor neurons responsible for movement, but one sure fire way to do so is through an intense workout while already fatigued. In this depleted situation, further workouts will inhibit muscle regrowth and reduce exercise performance.

To prevent this problem, a smart strategy is needed. One that accelerates recovery without interfering with training load – such as BFR.

Don’t just take our word for it. A number of studies have been done on the impact on HRV of BFR training.

• Karabulat and Sato, as well as Keayney et.al, showed that aerobic exercise training combined with BFR brought about improvements in VO_2max, along with similar gains in muscle strength and hypertrophy, compared with high-load exercise in young healthy men.
• Studies by Loenneke et.al and Marcell et.al showed equal or lower blood pressure responses to exercise when performed with BFR compared to high-load exercise without BFR. This indicates reduced stress on the nervous system when using BFR.
• A recent experiment by Park et.al found a combination of low-intensity walk training and BFR a successful strategy to improve cardiovascular function, muscular strength and hypertrophy. The combination showed similar improvements to those seen in intense aerobic exercise without BFR. Similarly, Junior et.al found that walk training combined with BFR improved resting HRV and lowered blood pressure. Both studies illustrate BFR as an effective way to improve both HRV and recovery.

And that’s not all! For those who don’t fancy stretching their legs with a walk, passive BFR provides a simple and effective tool for accelerating recovery and reducing stress from exercise while providing a similar physiological response to walk training. Just five minutes of BFR is enough to significantly enhance recovery – and help your HRV!

Getting Started with HRV and BFR

With the widespread adoption of physiology trackers, it’s never been easier to measure your HRV. Read here [link to article] for full details on how to access your HRV data with a range of trackers. Active and passive BFR are both backed up by the science when it comes to improving your HRV and getting ahead of the curve with your recovery. Which one you choose to use depends on just how high your HRV is – and how primed your body is for performance.

When you start to use BFR as a strategy for enhancing HRV you take the stress out of training. By keeping it smart, gradual improvements in average HRV will follow. Soon enough, you’ll be training more efficiently than ever before. Most importantly, you’ll understand exactly what it is that your body is trying to tell you.