You may have seen HRV popping up everywhere, on your smart watch, recovery scores, fitness apps, and especially in the world of biohacking trends. However, HRV isn’t a new wellness trend, it’s been used in research and clinical settings for decades.

There are many people now prioritising HRV as something to track and even optimise, in the hope it will lead to better health, energy, or resilience. But despite how often we’re seeing it around, HRV is rarely explained clearly. And without context, it can easily become just another number to fixate on.

So let’s break it down and talk about what HRV actually is, what the science says, and how it can be used in a way that’s supportive and not stressful.

What is HRV, Really?

HRV stands for heart rate variability, but it’s not about how fast your heart beats, instead it refers to the tiny variations in time between each heartbeat. Even when your heart rate looks steady, the space between beats is constantly shifting, and that variability reflects how well your nervous system is functioning.

More specifically, HRV reflects the balance and interaction between your:

• Sympathetic nervous system (stress response / fight to flight)
• Parasympathetic nervous system (rest, digest, recover)

Together, these form your autonomic nervous system, the part of the nervous system that regulates things you don’t consciously control, like heart rate, digestion, breathing, and stress responses.

Without fixating on numbers, and looking for the perfect score, a higher HRV is associated with better adaptability and nervous system flexibility, and a lower HRV may reflect higher stress load, poorer recovery, inflammation, illness, or lifestyle strain.

One key point the science supports again and again is that HRV is highly individual. Age, sex, genetics, sleep, mental load, training status, illness, and even cycle phase can all influence readings. This is exactly why comparing your HRV to someone else’s isn’t helpful. What matters far more is how your HRV changes over time, rather than any single number.

What Tends to Lower HRV?

As mentioned earlier, fixating on the number itself isn’t necessary. But understanding what influences HRV can be genuinely helpful, not just for HRV, but for overall health and wellbeing.

Some of the most common factors associated with a dip in HRV include:

• Chronic stress or anxiety
• Poor or inconsistent sleep
• Blood sugar instability
• Illness, inflammation, or recovery from infection
• Overtraining (or simply not recovering enough)
• Nutrient depletion or low diet quality

Research has also linked HRV changes to body composition and adiposity (the amount and distribution of body fat) too. For example, studies in women have shown that HRV can be lower at both ends of the spectrum, so in those who are underweight and in those who are overweight, compared to those in a more balanced range.

This too suggests the nervous system doesn’t cope well with extremes. It tends to function best when the body feels adequately nourished, supported, and stable, rather than under fuelled or under constant strain.

It’s a helpful reminder that supporting HRV (and health more broadly) isn’t about pushing harder, eating less, or controlling the body, it’s about creating conditions where the nervous system feels safe enough to adapt.

There’s growing interest in HRV as a potential biomarker for how nutrition influences both physiological and psychological health. Research reviews consistently show that diet quality matters, and that certain dietary patterns are linked to more favourable HRV outcomes.

For example, a Mediterranean style diet, rich in things like omega 3 fats, B vitamins, polyphenols (plant compounds), probiotics and fermented foods, has been associated with improvements in HRV. On the flip side, higher intakes of saturated fats and low quality, high glycaemic dietary patterns have been flagged as less supportive in this context.

Now, does that mean one meal will raise your HRV? No. But it does support something we already know clinically, that the nervous system responds to the overall environment you create inside the body.

Certain nutrients also appear repeatedly in the HRV research, suggesting they may play a supportive role. These include:

• Omega-3 fatty acids (commonly linked with parasympathetic support)
• Vitamins D, B12, C, E
• Minerals like magnesium, iron, zinc
• Compounds like coenzyme Q10

One really interesting study found that simply swapping typical snack foods for whole almonds improved the parasympathetic HRV measure during a mental stress task. Again showing that diet may help buffer the stress response, and without the need of any drastic changes.

Supplements we Recommend for Nervous System Support

Alongside nutritional support, there are some supplements that we would personally recommend for supporting the nervous system, stress resilience, and overall health.

None of these are about “boosting HRV” directly. Instead, they support the systems that influence HRV, including the autonomic nervous system, cardiovascular function, stress response, and recovery capacity.

Terranova Smooth Synergy:

This is actually one of our top selling supplements, and has been for years. It’s a gorgeous blend of vitamins, minerals, and botanicals that support the nervous system as a whole (hence the name). It contains key nutrients that repeatedly show up in HRV research including magnesium, B12, and vitamin C, alongside adaptogenic herbs such as ashwagandha and rhodiola, which are commonly used to support stress resilience.

It’s one of those supplements that both customers and even us too, often return to during periods of stress or overwhelm, because it genuinely supports the body when the nervous system feels under pressure. In the context of HRV, it fits perfectly by supporting regulation rather than stimulation.

Bare Biology Omega 3:

Omega 3 fatty acids are essential, quite literally. The body can’t make them, yet they’re involved in everything from cardiovascular health and inflammation balance to brain and nervous system function.

From an HRV perspective, omega 3s are particularly interesting because research has linked them with enhanced parasympathetic (rest and digest) activity, which is a key part of healthy HRV patterns. They’ve also been studied in relation to stress physiology, including cortisol regulation.

We love Bare Biology oils because the dose is therapeutic with around 3.5g per teaspoon, and the purity and oxidation standards are exceptionally high, which really matters with omega 3s.

Viridian Vitamin C:

Vitamin C is often talked about in the context of immunity or skin health, but in our opinion, it deserves far more attention for stress and nervous system support.

One important (and often overlooked) fact is that the adrenal glands, which produce cortisol (our primary stress hormone), are the only glands in the body that store vitamin C. So as you can imagine, during periods of stress, those stores are used up quickly.

So when stress is high, vitamin C demand increases, and depletion can affect multiple systems, including energy, recovery, and nervous system balance. For us, vitamin C sits right at the top of the list when supporting stress resilience and overall regulation.

Pure Encapsulations Magnesium Glycinate:

Magnesium is one of the most important minerals for nervous system function. It plays a role in nerve signalling, muscle relaxation, sleep quality, and the body’s ability to shift out of a stress response. In HRV research, magnesium frequently appears in discussions around autonomic balance, particularly in relation to parasympathetic activity.

We choose magnesium glycinate because it’s well tolerated, gentle on digestion, and especially supportive for relaxation and stress. It’s a foundational supplement for many people no matter their life stage, but particularly during busy or demanding times of life.

Viridian B12 Complex:

Vitamin B12 (along with other B vitamins) is essential for energy metabolism, nerve function, and stress resilience.

Research exploring micronutrients and HRV has consistently noted links between low B12 status and reduced HRV, particularly in populations under higher physiological strain. B12 supports the nervous system’s ability to respond appropriately to stress, without tipping into depletion.

The reason we recommend a B12 complex, is because they work synergistically together. This particular blend has all the B vitamins, but a higher concentration of B12, and it’s great for those under prolonged stress, those eating little animal protein, or those feeling wired but tired.

Viridian Vitamin D3:

Vitamin D is another nutrient that’s often underestimated when it comes to nervous system regulation.

Low vitamin D status has been associated in research with reduced HRV, and it plays a role in immune regulation, inflammation balance, and overall autonomic function. Given how common deficiency is, especially in the UK, vitamin D is a really important part of supporting long term health and resilience.

Exercise and physical activity are, of course, key components of overall health, and they’re closely linked to HRV too.

At rest, higher HRV is frequently associated with:

• Higher fitness levels (often measured as VO₂max)
• Greater physical activity
• Better quality of life scores

What’s particularly interesting is that some research suggests HRV changes when moving from lying down to standing — a simple physiological challenge — can reflect how adaptable the body is. These changes have been shown to correlate with fitness and lifestyle measures, reinforcing the idea that HRV reflects adaptability, not just rest.

However, it’s also important to remember that not all exercise affects HRV in the same way in the short term. Reviews looking at resistance training suggest that acute resistance exercise can temporarily reduce parasympathetic activity, particularly in younger adults, sometimes more so than aerobic exercise. That doesn’t mean resistance training is bad as such, it simply means the body is responding to a stressor.

This is where recovery becomes just as important as the exercise itself. HRV often reflects how well the body is adapting after training, not just how much movement is being done.

Measuring HRV: Do You Need a Wearable?

Most people now come across HRV through wearables, which tend to use pulse based estimates. These can be useful, but accuracy can vary depending on movement, stress levels, and how (and when) the measurement is taken.

So if you’re using HRV at home, the best approach is:

• Measure at rest
• Measure consistently
• Look for trends over time

If you’re wondering whether you need a wearable or tracking device, the answer is no, not at all. And this takes us to something we have found absolutely fascinating - the Global Coherence app.

Rather than using a wearable, this app allows you to measure your heart rhythm patterns using a simple finger reading through your phone camera. It works by analysing pulse wave signals from the finger, a technology that’s becoming increasingly common as measurement tools evolve.

What we really like about this app is how accessible it feels. It doesn’t just give you data, it helps you understand what’s influencing it, particularly from an energetic and nervous system perspective. It encourages a shift into a calmer, more regulated rest and digest state, and shows how breath, focus, and emotion can change heart rhythm patterns in real time.

The app also offers communal coherence sessions, which are a lovely way to explore HRV while actively practising regulation. It’s also a reminder that nervous system health isn’t just individual, it’s influenced by connection and environment too.

It’s important to say that this app isn’t a diagnostic tool, and it shouldn’t be used to judge yourself or chase a perfect reading. But it can be brilliant for learning how quickly your body responds to breath, attention, and emotional state.

So… Can you Improve HRV?

Yes, but not through chasing numbers. HRV tends to improve when the inputs improve, like:

• Sleep quality and consistency
• Stress management and emotional regulation
• Balanced blood sugar and stable meals
• Sensible training + recovery
• Better nutrient status

And for many people, the biggest HRV win is by simply reducing overall load and increasing recovery capacity.

Overall, HRV isn’t about control or perfection. If your HRV is lower during stressful times, that doesn’t mean you’re doing anything wrong, it just means your body is responding to life and that awareness can be the first step towards supporting it better.

And that, ultimately, is what heart health is really about.