BodyCheck is a bespoke algorithm integrated into the Prevayl App. It offers invaluable insights to streamline your recovery process, with the goal of helping you achieve your fitness goals safely. To ensure maximum benefits of BodyCheck, it is essential to adopt specific strategies that optimise data accuracy and consistency. In this article, we explore three key ways to maximise the benefits of BodyCheck.

If you’re new to BodyCheck, click here to explore its incredible capabilities.

1. Perform BodyCheck at the Same Time Every Day

Consistency is key when using BodyCheck to assess your readiness to perform. The best time to do BodyCheck is right after waking up, be it in the morning or later during the day, as this helps establish a reliable baseline and enables accurate tracking of physiological indicators over time. By adhering to a consistent schedule, you can capture reliable data and effectively monitor progress and changes in your body's responses to training and recovery activities.

Doing BodyCheck at the same time daily eliminates potential variations caused by factors such as sleep, nutrition and stress levels. This consistent approach ensures that the collected data provides a true representation of your physiological state and allows for more accurate analysis and informed decision-making.

2. Conduct BodyCheck in the Same Condition

To obtain accurate and reliable data with BodyCheck, it is crucial to perform it in the same condition each time. Specifically, avoid consuming caffeine or pre-workout supplements before conducting BodyCheck. These substances can elevate heart rate, blood pressure and other physiological parameters, potentially influencing the data collected by the device.

By abstaining from caffeine and pre-workout supplements, you ensure that the physiological responses measured by BodyCheck are not artificially enhanced or altered. This practice enables a more accurate understanding of your body's intrinsic responses to training and recovery activities, allowing you to make informed adjustments to optimise your performance and progress effectively.

3. Follow User Guidelines and In-App Instructions

Proper placement of the Fiit Tracker or SmartWear™ is crucial for obtaining accurate and reliable data in BodyCheck.

First, you should ensure that the smart underband is making optimal contact with your skin, as this significantly enhances the accuracy of the collected readings. Additionally, it's important to pay attention to your body positioning and carefully follow the in-app instructions. We advise starting in a lying-down position and promptly standing up as soon as you hear the beep to prevent any potential distortion in the data.

By following these recommended guidelines, you can acquire the most precise data to assess your recovery progress and make well-informed decisions regarding your fitness goals.

Consistent and accurate data tracking empowers you to make informed decisions about training intensity, recovery strategies and overall performance optimisation. By incorporating these strategies into your BodyCheck routine, you can unlock the full potential of BodyCheck’s valuable insights.

If you have further questions about BodyCheck or would like to speak to the Prevayl team, please contact us at enquiries@prevayl.com.

New to BodyCheck? Here are some tips to help you optimise your BodyCheck experience and maximise your fitness journey whilst prioritising your safety.

3 Ways to Maximise the Benefits of BodyCheck™ | Prevayl

3 Ways to Maximise the Benefits of BodyCheck™

New to BodyCheck™? Here are some tips to help you optimise your BodyCheck experience and maximise your fitness journey whilst prioritising your safety.

The Prevayl SmartWear™ range combines convenience and comfort to enhance your workout experience. With its compact design and rechargeable battery, the Sensor offers hassle-free usage and eliminates the need for battery replacements.

In this article, we will explore the features of the Sensor, its battery performance and how to maximise its lifespan.

The team at Prevayl has prioritised user experience by designing the Sensor to be small and unobtrusive during workouts, which ensures that it does not interfere with your exercise. The compact lithium-ion rechargeable battery further contributes to its convenience, allowing for extended usage without the hassle of purchasing and replacing batteries.

Careful consideration went into selecting the battery for the Sensor. Whether it’s a workout or a BodyCheck™, the Sensor is designed to last. Unlike other heart rate Sensors, you won’t have to worry about buying and replacing batteries; simply charge it using the provided USB cable.

To give you a better idea of the battery performance, below are some statistics from a Sensor with v21.1.0 firmware.

During periods of inactivity, the Sensor conserves battery power. The graph illustrates the battery percentage over time, indicating the device’s extended lifespan when not in use.

Test was conducted using a new Sensor at 100% charge and was tested to take around 125 hours to reach 0% when left not connected to Bluetooth and with the sensing pads not touching anything.

When actively using the Sensor, i.e. you’re doing a workout or a BodyCheck™, the graph below shows the battery percentage reducing over time, highlighting its longevity during workouts. This provides peace of mind, ensuring that the device won’t run out of power during a class.

Test was conducted using a new Sensor from 100% charge and connected to a heart rate simulator.

The results of the test show that during activities it would take around 37 hours to reach 0%. 

Charging your Sensor is quick and efficient. Even if you find that it has a low battery before a workout, just a quick five-minute charge will give you enough power for an hour of usage. The graph below illustrates the battery percentage increase during charging, demonstrating how rapidly the Sensor replenishes its power.

Test was conducted using a new Sensor from 0%.

The results of the test show that it takes 1.5 hours to reach 100% when connected to a socket with USB and not connected to a phone with Bluetooth.

Depending on the particular battery, the level may continue to drop beyond what is shown as 0% so if the Sensor is completely out of charge then it may take a few minutes to reach the level which is shown as 0% in the above graph. Likewise, the battery may be able to continue charging beyond what is shown as 100%. This is due to the protection we have in place to ensure the battery never hits a true 100% or 0% to prolong the life of the battery, as per standard practice with consumer electronics.

It is advisable to remove the Sensor from charging once the LED indicator turns green (which indicates that the battery is at 90%) to optimise the battery’s performance and longevity.

Lithium-Ion batteries can be quite variable and how they charge and discharge can be unintuitive. For example: charging and discharging is not symmetrical or linear; charging happens in a curve whereas discharging is relatively flat when you look at the percentage.

For our testing, a new Sensor was used which had only been charged and drained a few times. The Sensor was fully charged before the discharge testing was done each time and when looking at our graphs you may expect to see a similar lifetime only in similar circumstances. Please consider these graphs as representations of best-case scenarios. If you have been using your Sensor for an extended period, it is reasonable to anticipate an additional half an hour for reaching 100% during charging or a slightly reduced battery life when left idle for a few hours.

Things like the age of the Sensor, whether it is fully charged from a flat or only part charged, and temperature can all make the battery lifetime vary and potentially decrease noticeably, which is common for lithium-ion batteries. Whilst we anticipate that the majority of our Sensors can maintain a similar lifetime based on our tests, it is important to acknowledge that there may be a few instances where performance may be different.

If you encounter any issues with the Sensor’s battery performance, or you believe that your Sensor isn’t performing as expected, please feel free to reach out to us at enquiries@prevayl.com. We will be more than happy to assist you and discuss replacement options.

The compact, rechargeable Prevayl Sensor ensures hassle-free usage and eliminates battery replacements. Discover tips to extend its battery life.

A Guide to Maximise Prevayl Sensor Lifespan | Prevayl

A Guide to Maximise Prevayl Sensor Lifespan

SmartWear™ is the world’s most accurate smart clothing.

Engineered to guide your training and help take your performance to the next level, SmartWear™ is clothing that you actually want to wear every time you hit the track or the treadmill.

Smart clothing, also frequently referred to as high-tech clothing, is clothing that’s enhanced with technology to offer functionality beyond their traditional use. 

Some smart clothing uses advanced textiles with interwoven technological circuits whilst others implement external hardware, which is connected to a smartphone app to offer its smart functionality – and then there's SmartWear™, which combines all of the above to deliver the most accurate performance insights in the market. 

There’s no denying that wearables are getting more advanced, but even with today’s technology, they may not be offering you the most accurate insights. Enter SmartWear™. It combines the power of the Prevayl Sensor and a smart underband in each garment to help you become a supercharged version of yourself by wearing it and integrating the insights it offers into your training. 

Unlike most wearables and fitness trackers, which are typically strapped to your wrists, SmartWear™ strategically places the Prevayl Sensor close to your chest. This enables us to track your heart rate as well as measure data previously left unmonitored, like your breathing rate and breathing variability, via the chest cavity. That means we’re able to capture optimal biometric reading, which leads to more reliable and more personalised training recommendations to take your workout to the next level. 

SmartWear™ sets itself apart from the competition by solving the problem in a different way: we gave our techies and engineers the task of developing SmartWear™, with the idea of invisibly integrating the Prevayl technology into gym garments that have been designed for everyday wear. 

Meanwhile, we tasked our health experts, sports scientists and data scientists with taking complex body data, applying it to the latest research and translating it into simple instructions for the wearer that will leave them feeling empowered and have the maximum impact on improving their health, fitness and wellbeing. 

The advanced algorithms we’ve created give the average gym goer real-time medical, fitness and lifestyle insights which, just a few years ago, were only accessible to patients in a lab environment and elite athletes. SmartWear™ is also designed to meet the fashion needs of everyone who wants to train more effectively and look good doing it, so it’s super simple to integrate it into the rest of your workout wardrobe. 

Shop SmartWear™ now – explore Men's and Women's Training Packs.

SmartWear™ is the next generation of sportswear, combining smart clothing and wearable technology to deliver actionable insights that level up your training.

Everything You Need to Know About SmartWear™ | Prevayl

What Is SmartWear™: The Future of Sportswear

West Ham United and England superstar, Declan Rice is the latest Prevayl Pro to join our elite team of sporting greats. We sat down with Declan following his first training session with Prevayl to talk all things leadership, childhood and that winner's mentality. We’re thrilled to have Declan on the team and looking forward to supporting and tracking his training journey with Prevayl SmartWear™.

Where did you love for football come from?

The first memories I have of football are with my parents. We have family photos of me at home in the garden, still in a nappy kicking a ball as soon as I could walk. My dad always took me down to the local park and threw it or kicked it to me, so I could kick it back to him. I was out there even if it was raining or snowing. So my parents definitely knew what I wanted to do from a very young age.‍

How did you juggle childhood with football training? Did you have to trade off a 'normal' life for training?

I was very close to my mum and dad, we did everything together. So moving away from home, my family and friends and starting a new school when I joined West Ham was a big decision! I was homesick for a couple of years, but it was the right route for me. I didn’t do the house parties or any of the stuff other kids my age were doing, but I’ve put in the work and I’ve had experiences in football I would never want to change.‍

How do you remain level-headed when you hear that you could be the next Premier League or England great?

You can never let these things get in your head. You mustn’t get complacent, but you also can’t allow yourself to feel the pressure. You have to keep working hard and focusing on being the best you can be. There are a lot of proud West Ham people because I am playing for England and of course I’d love to be a Premier League/England great – but I don’t focus on that.

Do you think it's important to have likeminded and motivated people around you to make it all the way to the top?

I think it’s really important in football to motivate yourself. You have to want it, at all times. There are players out there who are amazingly talented but haven’t gone as far, just because someone else wanted it more. But of course it helps to have other likeminded people around you, to inspire you and push you. You can see how happy I am on the pitch! ‍

How important is the mental game and psychology of sports and performance?

It’s really important. I don’t get fazed too easily to be honest. You have to be on your game constantly. The competition is strong, so you need to keep your head down, keep working and make sure the manager can’t leave you out. I try to think long-term; if one game doesn’t go how I wanted it to, I try to focus on the fact the next game is an opportunity to right any wrongs and improve on that performance.‍

What techniques have you adopted to cultivate that winning mentality?

One piece of advice that has really helped me in my career is “you train how you play”. If you train and give your all from Monday to Friday, it’s likely that on Saturday you’ll be the most prepared you can be to perform. So physically, and mentally – you’re in the zone and no one is going into that game with an upper hand on you.

Being a part of the England set up this summer must have been amazing; Have you had a chance to process the whole experience?

It was the most incredible experience! I watched England’s last tournament in the 2018 World Cup as a fan on holiday in Dubai, so I feel so grateful and proud to have been a part of England’s journey to the Euros finals. Of course we were disappointed not to win, we went in fully believing that we could but we’re taking the positives away and we’re ready for the World Cup. We’ve learnt a lot.‍

There seems to be a real togetherness within the England squad, how do you push club rivalries aside when you're battling against each other week in, week out?

Even in the Premier League, once the final whistle has blown there’s nothing but respect and friendship for other players, no matter if they’re your biggest club rival. There’s such sportsmanship. The Euros was such an amazing experience and it brought us all even closer together, the highs and the lows. We’ve built something really special and I can’t wait to see how that develops for the World Cup.

West Ham captain Declan Rice shares how he keeps his head in the game, how he handles success and what it’s like to play for the England national team.

Declan Rice: How to Cultivate a Winner’s Mindset | Prevayl

Declan Rice: How to Cultivate a Winner’s Mindset

Whether you’re trying to lose weight, put on mass or maintain where you are, tracking your workouts is essential for evaluating where you are and where you want to be regarding your fitness. With the smartest Prevayl technology at your fingertips, tracking your workouts has never been easier.

If you’ve been hitting the gym but aren’t tracking your progress, keep reading to find out why it might be a good idea to start – and how Prevayl can help.

To effectively evaluate your progress, you need to track your workouts to see what you’re currently doing and what you need to do moving forward in order to reach your fitness goals. Not only that, tracking your workouts is also a great way to drive the direction of your training, keep yourself accountable and motivate you to push even further.

To help you achieve just that, we’ve created the Prevayl App.

The Prevayl App unifies all your fitness data captured by the Prevayl Sensor and SmartWear™ to give you a smarter way to track your workouts. By integrating your personalised fitness goals (that you set yourself) into your workout tracking, we empower you to monitor weekly improvements and see how your performance develops over time. Now you can spend less time fiddling with cryptic interfaces and more time tracking, analysing and progressing.

To start tracking a workout, simply tap the + icon > Workout > Select from the list of workouts you can track: 

With the live workout screen, you can monitor your performance every second of every session, from start to finish. This will help you ensure you stay in the correct Training Zone(s) for your goals as well as keep a close eye on your Body Load to stay safe in high-intensity training.

Depending on your workout, you may see different metrics when tracking your performance in real time. For example, workouts like outdoor cycle, hike, mountain biking, outdoor run and walk will measure the pace via GPS in addition to other Prevayl metrics.

With each workout, your TRGT is automatically tracked (providing that you’ve set your goals) and added to your weekly TRGT progress, giving you a better understanding of your fitness progress at a glance.

Is your preferred workout not on the list? You may select the option that best matches your activity. For instance, if you’re doing a workout on an elliptical trainer, choose Bike (Indoor), or Intervals if that’s what you’re doing. Our team is constantly working on adding more options to the list so keep an eye out for future updates.

To look back at your Prevayl journey, go to the History tab.

This is where you will find an overview of all your recorded workouts, BodyCheck™ and Guided Breathing sessions, plus your accumulated TRGT measured against the goal(s) you set yourself at the start of the week. Scroll to the bottom of the screen to find live stats from each workout you’ve done in the past week.

In just a few taps, you can see how your fitness story progresses. So, are you getting stronger? Faster? Fitter?

Ready to start tracking your workouts? It all starts with a Training Pack – shop our Men’s and Women’s collections now.

Tracking your workouts using the Prevayl App enables you to review your progress and evaluate your approach, maximising your gains from each session.

How to Track & Analyse Your Workouts Using the Prevayl App

Meet Katie Zelem, Manchester United Women’s midfielder and captain, and now, the newest Prevayl Pro. We invited Katie to Prevayl’s Manchester HQ to meet the team and experience the revolutionary Prevayl Sensor, SmartWear™ and App for herself.

After having her first taste of Prevayl, we sat down with Katie to chat about her favourite performance metrics in the Prevayl App, how her family have played a huge part in her success, what it’s like to captain one of the most influential football teams in the world, and more.

Q: What’s your first impression of the team behind Prevayl?

A: The first thing I noticed when I stepped into Prevayl HQ was how great the team is. Everyone is so friendly and welcoming. It was amazing to have a tour around the office and meet the everyone behind the brand, not just the people I’d be directly dealing with. It was really informative to get a bit of a backstory from the people who built the brand.

I’m from Manchester, so to see such amazing things happening in my home city is incredible!

Q: What are the key Prevayl metrics that you’ve found particularly useful?

A: For me, it’s really cool that I’m able to see my Training Zones and maximum HR, and really just all the data the App can show me. Also, I’m amazed by how quickly the data can come through from my body to the App, and how I can keep a constant eye on my performance during a workout.

Q: How does Prevayl compare to other fitness trackers you’ve used in your training?

A: We usually wear GPS trackers or HR monitors, but now that I’ve started wearing Prevayl, I think it’s really cool how the Prevayl Sensor is able to track all my workouts and give me all the data I need in real time.

Q: So, let’s take it way back, what inspired you to get into football?

A: When I was growing up, there was a really male-dominated environment around me – it was nearly all boys on the street I grew up in. My cousins, and obviously my dad and uncle, all played football, so for me it was like, “You either play outside with the boys or sit inside all day.”

It was very apparent from that point on that I preferred to be playing football with the lads, and it just became something I grew up doing: always having a football on my feet.

Q: Speaking of your dad and uncle, how have they supported your journey so far?

A: They’ve been hugely supportive. My dad and my uncle still try to come to as many games as possible so they can support me, especially the home games.

My dad travels near and far, whether it’s Manchester or London, to come watch me play. He hates missing games so he’s certainly my role model, along with my mum. They’ve both made so many sacrifices for me to be able to be where I am now.

Q: How do they feel about you now being the team captain?

A: The first time I ever captained Man Utd was at the Manchester derby, at the Etihad Stadium with 31,000 people watching, including my mum and dad. Unfortunately, there were so many people so I couldn’t see them but when the game finished, my dad told me my mum was crying at the game. She denied it but I know she did. They’re really proud of how far I’ve come and I’m so grateful that I can make them proud.

Q: What does a normal day entail for the captain of Man Utd?

A: There’s certainly a lot more responsibilities when you become the captain. You have to be involved in so many meetings, agendas and aspects of the team, but if you can take it in your stride, you can almost make it part of your normal routine.

Q: With so much going on every day, how do you keep yourself motivated?

A: You’ve got to be able to motivate yourself. Football is a very competitive sport. Everyone is fighting not only for places on the League tables but within each team, there are people fighting for starting spots, playing spots, substitution spots and so on. So you’ve got to make sure you stay motivated and be on top of your game for as long as you can. At some point, you’re bound to have some bad games and some down times. That’s just natural, not just in football but in life as well. It’s important to be able to pull yourself out of those bad times and it certainly helps to have a good support network around you whether it be teammates, friends or family.

Q: What are your ambitions for yourself and your team in the coming seasons?

A: There are many things I want to achieve as the captain of Man Utd: playing the Champions League and hopefully going on to compete at the League. As a club, I know we can get there so I hope I can continue to remain a solid name in football.

Q: Any tips for anyone who aspires to become a football player?

A: The key thing is to always enjoy it. I started playing football because I enjoyed it. It’s important that you’re still playing because you love it no matter how high up the pyramid you get.

Also, never let someone tell you no. Football is based so much around opinions: one manager could like you, the other might not. It’s just an opinion of one person. If you stopped doing what you love every time someone said no or you couldn’t do it, you wouldn’t get anywhere. It’s important to believe in yourself and stay resilient.

Q: Before we let you go, can you share a fun fact about yourself that would surprise most people?

Katie has harnessed the power to Prevayl to take her fitness up a notch – now, it’s your turn. Shop our Training Packs or browse Performance Wear, a collection of premium sportswear.

We sat down with Katie Zelem, the newest Prevayl Pro, to discuss the importance of having a support network, her life as the Man Utd captain, and much more.

Katie Zelem on Her Road to Manchester United Captain | Prevayl

Katie Zelem: Support Network, Life as a Captain & Favourite Prevayl Metrics

We sat down with Katie Zelem, the newest Prevayl Pro, to discuss the importance of having a support network, her life as the Manchester United captain, and much more.

Don't let appearances fool you; Prevayl SmartWear™ is no ordinary sportswear. Hidden within each garment is a smart underband, engineered to sit just below your chest to capture your biometric data with unrivalled precision.

But first, you need to find your size. This is absolutely paramount in order to get the most out of your SmartWear™. In fact, an ill-fitting garment is the most common cause of inaccurate or inconsistent data, so it’s worth taking a couple of minutes to check out the size guide to find your optimal fit.

In this article, we detail all your burning questions about our sizing system, from why the right size is crucial for a smarter workout and how to find it.

All SmartWear™ should wrap snugly around the chest at the sternum and feel tight enough that they don’t move around, but not so tight that it restricts your breathing.

The overall fit of the garment, however, differs depending on the item – Compressive Fit items should hug your body like a second-skin without feeling constrictive, whereas the Layered items offer a looser fit with the underband built underneath a regular fit t-shirt or tank.

The underband of your smart sports bra should run evenly around your ribs just below your bust. It needs to fit tightly enough so that it won't move around while you exercise. It should not, however, be so tight that it restricts your breathing.

In order to get the maximum benefit from your smart garment, the smart underband needs to make direct contact with your skin and remain so throughout the entire duration of your workout. This is vital to get the most precise readings of your cardio activities and movements. If the underband is too loose, it may slip or slide during exercise, which can lead to inaccuracy and/or inconsistency in the biometric readings.

To help you find the most accurate fit, we’ve put together a step-by-step guide to get your underband measurement.

Follow the steps below for men’s Compressive Fit and Layered items:

Wrap the tape measure under your pecs, not on your chest 

Pull the tape measure snug but not too tight 

Mark the measurement where your fingers meet

Follow the steps below for women’s Smart Sports Bra:

Wrap the tape measure around your body right under your bust where the bra band sits 

Pull the measuring tape snug but not too tight 

Mark the measurement where your fingers meet 

Use the chart above to convert your underbust measurement into a SmartWear™ Sports Bra Size*

*If your band measurement falls between two sizes, round down to the nearest whole measurement.

We hope you have all the information you need to make an informed decision. If you require further information, please get in touch via help.prevayl.com

Don't have a measuring tape? Don't worry, download this printable measuring tape and following the instructions to find your perfect fit.

Start training today smarter, shop our Men’s and Women’s collections.

New to Prevayl? Looking to get yourself a Training Pack? Follow this guide to find your underband size in our range of men’s and women’s smart sportswear.

Size Matters: A Guide to Find Your SmartWear™ Fit | Prevayl

Size Matters: A Guide to Find Your SmartWear™ Fit

It might feel as though your heart is beating at a steady pace, but contrary to the age-old belief, the heart at rest does not beat as regularly as a metronome. In fact, the time between your heartbeats is not consistent; this fluctuation of timing between heartbeats is called heart rate variability (HRV), which serves as a reliable indicator of your body’s recovery status and overall health.

In this article, we discuss how measuring HRV can help inform your fitness regime for maximum results – and how we do it.

Your heart changes its rhythm with every beat, and this constant variation in time between each heartbeat is known as HRV.

Picture this: If your heart rate is 60 beats per minute, you may assume that your heart is beating rhythmically every second. The reality is that, in a healthy heart, there’s a slight variability in the time between beats; there might be a 0.9 second gap between some beats and a 1.1 second gap between others.

These variations may be small (adding or subtracting a fraction of a second between beats) but they can indicate current or future health problems, such as heart conditions, mental health issues and, of course, under recovery.

Is HRV the same as an arrhythmia? HRV is a normal occurrence. It isn’t an arrhythmia on its own, which happens when your heart beats out of its usual rhythm.

Keeping a vigilant eye on your HRV can help you ward off injury, illness and overtraining. 

As a golden rule of thumb, a high HRV means your body is well recovered. When HRV is diminished for a period of time, it is a good indicator that you may be on the verge of overtraining or, at the very least, tired enough that your ability to respond to training is compromised.

By monitoring your HRV, you can stay informed about your risk of overtraining and your readiness to perform.

Reliable HRV analysis requires accurate measurement of each heartbeat and the time between beats. In a medical setting, an electrocardiogram machine (ECG) is considered the gold standard. In an ECG, sensors are attached to the skin of your chest to measure electrical activity of your heart to accurately measure HRV.

Outside of a medical setting, athletes and fitness lovers usually use smartwatches and wristbands to measure their HRV. The downside of this method is that such fitness trackers track your heart rate through the skin of your wrist, which isn’t sensitive enough to detect HRV accurately.

Prevayl offers a better, more accurate alternative. The smart underband in each SmartWear™ garment detects HRV straight from the source – your heart. This gives you the most reliable data that you can use to guide your training whilst minimising the risk of overtraining and injury.

BodyCheck™ is a feature in the Prevayl App which analyses your HRV (in combination with your resting HR) to determine the recovery status of your body.

Compared to the HRV test found in other fitness trackers, BodyCheck™ stands out for its ability to measure your HRV and resting HR in both lying down and standing up phases to identify signs of under recovery and overtraining. Whereas other fitness trackers typically only measure your resting HR and HRV in a lying down phrase, which is only sufficient for detecting under recovery and not overtraining.

It takes only three minutes to perform a BodyCheck™ and it’s best done in the morning when you wake up.

Results from your BodyCheck™ are then fed into a decision tree (which consists of your training frequency, number of rest days taken so far in the week, total number of high-intensity days so far, intensity of training in the previous day, and more) to produce a daily training recommendation on how to approach your training: whether you should train, rest or progress.

Make smarter training decisions with SmartWear™ – shop our Men’s and Women’s collections now.

HRV is the variation in time between each heartbeat. It’s leveraged in Prevayl’s BodyCheck™ to ensure you reach your fitness goals safely – click to read more.

What Is Heart Rate Variability & How It Is Measured | Prevayl

What Is Heart Rate Variability and How It's Measured

HRV is the variation in time between each heartbeat. Find out how we integrate it into the Prevayl App’s BodyCheck™ algorithms to ensure you reach your fitness goals safely.

When it comes to workout, you may be doing all the right things: you sweat, you squat and you sprint your heart out on the treadmill, but that doesn't mean you're always going to get an effective workout. In fact, soldiering through the same exercise routines will lead to plateau in workout performance and results… not to mention you'll get bored and lose motivation.

Sounds familiar? Then it’s time to put strategy back in your workout to make your progress go even further.

BodyCheck™ is a bespoke algorithm built into the Prevayl App, which empowers you to monitor how well your body adapts to your exercise routine, enabling you to balance between your training and recovery and smash every workout.

But first, we need to talk about heart rate variability (HRV)

In order to fully understand the benefits of BodyCheck™, we must first explain what HRV is, how it’s measured and why it matters.

Generally regarded as one of the best objective metrics for measuring your body’s readiness to perform, HRV is the variation in time between heartbeats.

Unlike measuring heart rate, which is about the average number of heart beats per minute, the measurement of HRV focuses on the small fluctuations of the heartbeat. These fluctuations can be affected by various factors, including but not limited to your exercise intensity, age, gender, diet, etc.

A low HRV (a small variability between heart beats) usually means that the body is under stress from exercise, whereas a higher HRV indicates that the body has a strong ability to tolerate stress or is strongly recovering from prior accumulated stress, which makes it favourable.

Such advanced levels of performance insights were once reserved for professional athletes; but now, thanks to modern technology, they’re available on demand, at your fingertips – in the form of BodyCheck™.

BodyCheck™ is more than just a HRV tracker; it’s the most detailed full body analysis distilled into the simplest training advice. It analyses more biophysical data than any other wearables on the market (including those that monitor your sleep) to guide your training every day.

By combining your HRV with your orthostatic heart rate, standing heart rate, electrocardiogram and personal baseline, BodyCheck™ calculates your daily recovery to determine your readiness for training.

The recommendation is then delivered through a minimalistic user interface, breaking a decision tree of over 63,000 branches down to one actionable step.

How BodyCheck™ Compares to Other HRV Tests

Many fitness trackers on the market offer HRV tests. However, they tend to only measure your resting HR and HRV in one position, which limits the amount of insight that they can obtain. Prevayl's BodyCheck™, on the other hand, measures your resting HR and HRV both lying down and standing up, which enables us to identify signs of both under recovery and over-training more accurately.

We recommend that you perform a BodyCheck™ every morning, preferably at the same time each day and under the same conditions, e.g. shortly after you wake up and before your first meal or morning coffee.. It takes only three minutes, and doing it consistently will help establish your personal baseline and improve your insight accuracy.

Follow these steps to perform a BodyCheck™:

Based on the outcome, you’ll be presented with one of three recommendations: train, rest or progress, to guide your approach to training that day. So you’ll know exactly when to push yourself and when to take it easy to get the most out of your training regime.

We recommend you do a BodyCheck™ at least three times a week, as this will help us maintain your personal baseline which we can then use to compare your daily metrics against.

BodyCheck™ is the most detailed and accurate tool on the market to help you better understand your recovery and how well your body adapts to your training.

What Is BodyCheck™: Understanding Your Training and Recovery

Prevayl is no ordinary sportswear. Hidden within each SmartWear™ garment are a smart underband created by our in-house team of experts to record the electrical activity of your heart and deliver clinical-grade ECG data to the Prevayl App in real time, giving you professional-level performance insights whilst negating the need for clunky chest straps.

But what’s an ECG? And how does it stack up to PPG, which is more widely accessible in the fitness tracker market? In this article, we’re addressing some of the questions you may have regarding the differences between ECG and PPG to deepen your understanding of your wearables.

Essentially, both ECG (electrocardiography) and PPG (photoplethysmography) are technologies used to examine how your heart is functioning, but with different methods.

ECG measures the bio-potential (or voltage) generated by electrical signals that control the expansion and contraction of the heart's chambers. Since ECG measures the electrical activity of the heart directly, it’s always best to take the measurement as close to the heart as possible, hence most ECG-based sensors utilise a chest strap with built-in electrodes. That’s also why we’ve positioned our dry electrodes in the smart underband of our SmartWear™ garments – for maximum accuracy.

On the other hand, PPG-based wearables shine a light source through the surface of skin and use a photodetector to measure the volumetric variations of blood circulation controlled by the heart's pumping action. Such wearables are typically wrist-worn devices, think Apple Watch, Fitbit, Garmin, Whoop, etc.

When it comes to accuracy, ECG presents a clear advantage over PPG, as it’s considered to be the non-invasive gold standard for cardiac monitoring.

ECG is used in the healthcare industry to help diagnose and monitor conditions affecting the heart, as well as to investigate symptoms of possible heart problems, such as chest pain, palpitations (suddenly noticeable heartbeats), dizziness and shortness of breath. While PPG relies on ECG signals as a reference for static HR comparison.

Since it captures measurement directly from the source: your heart, ECG can measure your HR more accurately. That’s why the Prevayl Sensor is designed to sit right below your chest, where we can capture the most precise data.

This is not to say that PPG-based wearables can’t do the same, but it tends to produce less accurate data during physical activity or cyclic wrist motions, thereby making ECG-based counterparts a much more reliable workout companion for high-performance athletes.

Can ECG and PPG measure heart rate variability (HRV)?

HRV analysis is traditionally performed on ECG, which is capable of extracting R-Peak Intervals (RRI) with millisecond accuracy. In other words, HRV data can be obtained with short-duration measurements. In fact, using ECG, Prevayl is able to examine your HRV and determine your readiness to perform  in three minutes – learn more about BodyCheck™.

For PPG sensors, peak interval accuracy is limited by usable sampling rate due to the high power consumption of LEDs. Not to mention that with PPG, pulse rate variation correlates with HRV for longer periods of measurement (more than five minutes), thus requiring long-duration windows of data to establish an accurate HRV.

ECG sensors tend to have extremely low power consumption, operating at low mW or µW. This is why our Prevayl Sensor can often outlast even the most impressive wrist-based PPG-based wearables in terms of power consumption. 

In contrast, most PPG sensors require higher power consumption – often orders of magnitude greater – due to the need of driving one or more LEDs approximately 30mW of operating power, which can reduce your wearable’s battery life.

The key challenges with PPG technology are cancelling the effects of ambient light, accommodating different skin colours and conditions (tattoos, eczema, etc.) and dealing with physical motion artefacts caused by movement. Not to mention that PPG can only be used on parts of the body that have a high concentration of blood vessels – for example, it can be difficult to get an accurate PPG signal from the wrist. 

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