What is Body Battery on your Garmin watch, and how can you boost it?

Young woman sitting in park checking smartwatch
(Image credit: Getty Images)

If you own a Garmin watch, you'll have a passing familiarity with the Body Battery score – a number out of 100 that roughly corresponds with how much energy you have for the rest of the day, declining throughout the day and rising at night. But what exactly does it mean, how it is calculated, and how can you give it a boost?

Body Battery is calculated using a combination of biometric readings collected by your watch throughout the day, and at night. These include your daily activities (incidental exercise like walking, as well as tracked workouts), your Sleep Score, and periods of rest (indicated by a low heart rate) and stress (calculated using heart rate and heart rate variability).

All this is done through the Firstbeat Analytics engine, which is Garmin's system for taking raw data and converting it into meaningful information that you can understand and use.

What does Body Battery mean?

The score gives you an indication of how much energy you have to tackle the day ahead. A high score means you should be able to handle an intense workout or a take on a stressful day without feeling burnt out at the end. If your Body Battery is still high by bedtime, consider doing more next time. It's fine to take it easy sometimes and we all need days to rest, but using energy while you have it will help your fitness and resilience in the long term.

If you wake up with a low score, however, you should take things a bit easier. Exercise is still important, but manage your expectations of yourself and try not to let your energy bottom out. These aren't days for setting new personal bests and achieving your full potential.

Your Body Battery will recharge overnight, but not necessarily all the way to 100. Things like insufficient sleep, poor sleep quality (too many interruptions, for example), alcohol, and illness can all prevent you starting the day fully rested and recovered. Your body battery may also stay lower if you're recovering from a tough workout.

Sometimes your body battery may be low for reasons that are personal to you. If you are naturally introverted, you may find big social gatherings stressful enough to have an impact, or you may be stressed out by driving.

Boost your Body Battery

If you find your Body Battery is often low, adjusting your daily habits can help you improve things. For example, you might be pushing yourself too hard with frequent intense workouts and not allowing yourself sufficient time to recover.

Drinking alcohol can also suppress your Body Battery while your body handles the stress of metabolizing it. Drinking may affect your sleep as well, and poor quality sleep over a sustained period will mean your score never rises to its maximum.

To give your score a boost in the short term, you can try taking some time out to relax (your watch has some simple breathing exercises that can help bring down an elevated heart rate), or take a nap of around 30 minutes, provided it's not too close to your usual bedtime.

You can make your Body Battery more resilient by using energy while you have it, and getting sufficient rest afterwards (ie building your fitness). This will let you work harder in future, with less drain on your reserves.

Cat Ellis

Cat is the editor of Advnture, She’s been a journalist for 15 years, and was fitness and wellbeing editor on TechRadar before joining the Advnture team in 2022. She’s a UK Athletics qualified run leader, and in her spare time enjoys nothing more than lacing up her shoes and hitting the roads and trails (the muddier, the better), usually wearing at least two sports watches.