You spend hours, days, weeks, months, even years optimizing your training, nutrition, and mind to perform at your highest level. You use machines and advanced training facilities, you take supplements, you time the weather, and you surround yourself with positive, inspiring influences so that at the end of the day, you know you put absolutely everything into meeting your goals. Obstacle course racers constantly push themselves to their limits to find out what they’re made of. Tracking training and biometric data on your phone or smartwatch is one way to get that full picture.

Heart rate, recovery time, VO2 max, training load, blood oxygen saturation, stress levels, and Personal Activity Intelligence (PAI) are all useful tools, but one of the most often overlooked stats is sleep. Amazfit’s T-Rex 2 smartwatch tracks the user’s length and depth of each night’s sleep (plus naps that last more than 20 minutes), along with how much time they spend in each stage of sleep, and breathing quality. It’s all presented in a graphical display on the Zepp app.

Related: Should the Amazfit T-Rex 2 Smartwatch Be Your New Training Partner?

According to the National Sleep Foundation, one third of adults suffer from insomnia nightly, and one half of adults experience insomnia at least a few nights per week. Insomnia is dead weight on your mood, cognitive capacity, and physiological health. Without adequate sleep, your training suffers — period. The third of five sleep stages is "deep sleep," in which your immune system replenishes. Loss of deep sleep causes the greatest impairments in daytime functioning. The fourth stage is "REM sleep," the purpose of which is to process stressors that you’ve experienced all day long and replenish the brain.

“If you DON'T snooze, you lose!” Jackie Oken, MED, NBC-HWC, a board-certified health and wellness coach with 40 years of experience in the health and wellness industry, says.

Oken is trained in cognitive-behavioral therapy for insomnia and other sleep issues. Sleep experts across the globe agree that this approach — unlearning and relearning thoughts and behaviors that affect sleep — has the highest success rate. Oken, based in Park City, Utah, developed and taught a 4-week course for insomniacs at a concierge medicine practice in Richmond, Virginia, and teaches sleep classes for physical therapy groups as well. She believes that sleep trackers can be beneficial if used correctly with informed expectations. Here are some things to consider when you're contemplating whether a sleep-tracking sports watch is worth it for you.

Is a Sleep Tracking Sports Watch Worth the Money?

“The greatest benefit to the sleep tracking concept is that people are finally giving sleep new attention that we didn't for a long time,” Oken says. “It used to be a badge of honor to say how few hours of sleep you got at night and how long you go without resting, but compelling data shows that being sleep-deprived is less healthy.

"The fact that people are willing to purchase trackers and pay attention highlights this new importance.”

Sleep data can be helpful in noting your sleep habits, such as how much sleep you get each night, which type of sleep you get, and at what points in the night you get each type of sleep.

One of the best examples of this is when sleep trackers see a clear decrease in sleep quality and quantity (and therefore athletic performance) after drinking more alcohol than usual. Being able to note direct cause-and-effect relationships between behaviors, sleep, and performance is key to maximizing the benefits of a sleep tracker. Perceived exertion is an important way to note performance and recovery. If someone can notice better performance on days after getting 7.5 hours of sleep the night before, that’s an effective use of the tracking.

Related: Just How Bad Is Alcohol for Your Health?

“The raw sleep data is not nearly as important as looking at changes, progression, and trends in your sleep,” Oken says.

So don’t worry about achieving the maximum amount of — and best quality — sleep possible. Rather, take in where you are today and what small steps you can take toward getting where you want to be. Clinically speaking, getting less than 5.5 hours of sleep each night is less healthy than more, but beyond that, we’re all different and our bodies have different needs.

Don’t Use Date to Psych Yourself Out

The worst thing you can do for your sleep is to take sleep data and turn it into evidence of insufficiency.

“Chronic insomnia is due to learned thoughts and behaviors,” Oken says. “Short-term insomnia develops into chronic insomnia as a result of worrying about sleep loss, so it’s important to reduce this worry that will, in turn, trigger the stress response and disturb sleep.

"Insomniacs tend to overestimate how long it takes them to fall asleep and how long they lay awake while underestimating how much sleep they do get. This stress warps the perception of time.”

Related: Want to Be a Great Athlete? Here Are 7 Ways to Start Sleeping Like One.

Make sure you’re viewing the sleep tracker data as useful information while monitoring your habits and paying attention to how you feel, not as an anxiety-inducing evaluation of sleep achievement. Also note that when you lose sleep because of a positive event (like staying up to witness a meteor shower or getting up extremely early to go for a training ride or run with friends), it doesn’t have as big an impact on daytime functioning.

Go All in on Healthy Sleep Habits

“If you’re investing in a sleep tracking device, go all in and invest in the rest of your sleep habits to go with it,” Oken says. “Try to go to bed and wake up at the same time every day. Don’t take naps longer than 45 minutes, and never after 3 p.m. Create a sleeping environment that’s quiet, dark, cool, and peaceful.

"Eliminate blue light devices before bed (phone, TV, tablet screens) that decrease the sleep hormone, melatonin. The best pre-sleep activity is reading a book with a dim light bulb (not fluorescent).”

The tracker should be verifying all of the impact that your good, healthy, relaxing habits are having on your sleep. People who just look at the data and don’t do the rest of the work might get upset and create sleep-compromising stress. Let the tracker be just a part of your holistic approach to sleep and a tool that tracks your progress trending in the direction you want to go.