Polar Grit X2 Pro Titan

Polar Grit X2 Pro Titan is a rough and rugged outdoor sports watch crafted for adventure with sapphire glass AMOLED display in titanium casing, and a hi-tech toolkit of navigation and performance features for exploring the wonders of the world, and the body.

Polar Grit X2 Pro

Polar Grit X2 Pro is a rough and rugged outdoor sports watch crafted for adventure with sapphire crystal glass AMOLED display, and a hi-tech toolkit of navigation and performance features for exploring the wonders of the world, and the body.

Polar Vantage V3

An ensemble of biosensing instruments, AMOLED display, dual-frequency GPS, maps, and the most comprehensive suite of training and recovery tools on the market. The stage is set, and the Polar Vantage V3 smart sports watch is ready to put in the performance of a lifetime.

Polar Ignite 3

Polar Ignite 3 is a stylish fitness & wellness watch that helps you live a more energized life. It tracks your sleep, activity, and heart rate to provide guidance that’s tailored to your body and lifestyle.

Polar Pacer Pro

Polar Pacer Pro is an ultra-light, new-generation sports watch with integrated barometer that equips athletes with advanced tools to improve running economy, training sessions, and sports performance.

Polar Pacer

Sport is play – why complicate it? Polar Pacer is a no-nonsense sports watch that gives new athletes all the essentials, plus the specialized training tools they need to train better.

Polar Vantage V2

A powerful convergence of minimalist design, innovative technology, and intelligent training and recovery tools make Polar Vantage V2 our most formidable sportswatch to date.

Polar Grit X Pro

Built for military-level durability with sapphire glass and ultra-long battery, equipping you with new navigation tools, always-on outdoor features and Polar's ultimate training solutions.

Polar Vantage M2

Designed for function, the Polar Vantage M2 works as hard as you do. Our industry-leading technology is here to help you reach your goals and come back stronger. For that athlete attitude.

Polar Ignite 2

A fitness watch that’s sleek, simple and smart? Polar Ignite 2 is a true triple threat. Versatile and full of great features, it’s the perfect companion for any sport and any lifestyle.

Polar Ignite

A waterproof fitness watch with advanced wrist-based heart rate and integrated GPS, Polar Ignite offers you a full view of your day and guides you towards a more balanced life.

Polar Unite

A beautifully simple watch with personalized daily workout guidance, 24/7 heart rate and activity tracking, plus automatic sleep and recovery applications.

Polar Vantage M

An all-round multisport & running GPS watch for anyone who loves setting new records. Polar Vantage M is a slim, lightweight training companion that gives you all the data you need to improve your performance.

Polar Grit X

An outdoor multisport watch with rugged yet lightweight design, ultra-long battery life and military-standard durability for anyone who prefers the trails over the roads.

Polar M430

A GPS running watch with wrist-based heart rate, advanced running features and Polar Running Program, Polar M430 is a top-level watch for runners who want more.

Polar Verity Sense

When freedom of movement is important to you, Polar Verity Sense is your go-to choice for any sport.

Polar H10

Widely regarded as the gold standard in wireless heart rate monitoring, this is the most accurate sensor in Polar’s history.

Polar H9

A reliable, high-quality heart rate chest strap for all your everyday sports with Bluetooth® and ANT+ connectivity. Get connected and get going.

Polar OH1

Polar OH1 is an optical heart rate monitor that combines versatility, comfort and simplicity. You can use it both as a standalone device and pair it with various fitness apps, sports watches and smart watches, thanks to Bluetooth® and ANT+ connectivity.


Personalize any watch for any style and any need.


Replace or upgrade your Polar Sensor chest straps or arm bands.

Power & Cables

For charging your products and data transfer.

Mounts & Adapters

Adapt your product for any situation.





Polar Grit X Outdoor Series

Made for outdoor sports and built to handle any environment nature can throw at you, Grit X watches are designed to help you explore the world and gear up for adventure.

Polar Vantage Performance Series

Our flagship series is tailored for high-performance and endurance sports and training. Every aspect of our Vantage watches are designed with one particular person in mind – the athlete.

Polar Pacer Multisport Series

The Pacer Series gives athletes all the essentials such as accurate GPS and precise heart rate tracking, plus the specialized training, sleep, and recovery tools they need to train better.

Polar Ignite Fitness & Wellness Series

Sleek, simple, and smart – Ignite watches are the perfect partner for any fitness goals and any lifestyle.

Energy sources

The energy sources breakdown shows how much of different energy sources (fats, carbohydrates and proteins) you used during your session. They are illustrated as percentages of your total calorie consumption.

During physical activity, your body uses carbohydrates and fat as its main sources of energy. The higher your training intensity, the more carbs it uses in proportion to fat, and vice versa. The role of protein is usually quite small, but during high intensity activity and during long sessions your body can use about 5 to 10 % of its energy from protein. When experiencing glycogen depletion, protein consumption is higher.

The use of different energy sources is calculated based on your heart rate, but your physical settings are also taken into account. These include your age, gender, height, weight, maximum heart rate, resting heart rate, VO2max, aerobic threshold and anaerobic threshold. It's important that you've set these settings as precisely as possible, so you'll get the most accurate energy source consumption data.

On your watch the energy nutrients breakdown can be viewed in the training summary right after your session. You can see how much of each nutrient you've used during your session in percentages. Note that when planning your post-session nutrition, the percentages of carbohydrates, fat and protein consumed during exercise shouldn’t be used as a guideline. This is because carbs, fat and protein play different roles as energy sources than as a nutrients on your plate. For example, protein doesn’t play a big role during exercise, but it is an important nutrient in your daily intake.

How to benefit from knowing how much energy sources you used

Seeing how much of different the energy sources you used during your session allows you to learn how different intensities affect your energy usage. You can also spot how the main energy source can change during a long session. Knowing your energy nutrients is also useful if you’re looking to improve your body’s ability to utilize body fat as an energy source with long duration low intensity training.

In the Flow mobile app you can view how much of each energy source you used at each point of your session and how their ratios changed during it. The graph shows how your body makes use of different energy sources at different training intensities, and also at different stages of your training session. You can also compare the breakdown from similar sessions over time and see how your ability to use fat as the primary energy source develops.

Note that the detailed analysis view is only available in the Flow mobile app. In the Flow web service you can see the basic percentage breakdown for the session.

Scientific background

The algorithm estimates the amount of carbohydrates, proteins and fats of the total kilocalories consumed during physical exertion. It assumes that the availability of glycogen as a source for carbohydrates is limited but that the availability of fat and protein is unlimited. It also assumes that glycogen stores are full at the start of the training session. The relative consumption rates between carbohydrates, proteins and fat depend on exercise intensity measured with heart rate, and the glycogen available. Resting heart rate, aerobic heart rate threshold, anaerobic heart rate threshold and maximum heart rate have a significant effect on the relative consumption rate of carbohydrates, proteins and fat at a certain heart rate.

The model was validated by simulating multiple possible exercise types with multiple artificial physical background parameters representing both males and females of various ages, heights, weights and with training backgrounds ranging from occasional trainers to pro athletes. Parameter combinations with exceptionally low or high body mass indexes were excluded. The reference values for the relative energy consumption were defined by a sports nutrition specialist based on a review of various scientific papers and textbooks and practical knowledge. The results of the validation showed a good correlation between the model and the expected fractions for fat, carbohydrates and proteins.

Further reading


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