Timing Peak Performance with the Help of the Polar Vantage V3

Ferenc Soma Kovács, national team athlete of SVSE, senior World Championship participant, National Champion in middle-distance running. 800m: 1:47.92, 1500m: 3:34.79 (national record)

 

Peaking in a Runner’s Competitive Season

Competitive athletes are generally unable to compete in their best mental, emotional, and physical condition throughout an entire season. Doing so would mean delivering a perfect individual performance at every event—which, let’s be honest, is simply not realistic. Instead, they adopt a more forgiving approach with themselves: early-season races are often approached with lower expectations and under the load of intense training blocks. At the same time, they strive to perfectly calibrate the factors within their control—such as sleep quality and quantity, weekly mileage, and interval training intensity—so they can toe the start line in the best possible condition for their key race(s).

With this in mind, it is absolutely essential to identify as many measurable factors as possible whose neglect leads to a decline in performance, while their improvement results in enhanced outcomes. Next, the methods that allow for the clear quantification of these factors must be identified. Thanks to advances in sports science and the accessibility of technology, we can now easily and comfortably perform physiological measurements at home with our wrist-worn sports watches — measurements that were previously conducted exclusively in laboratories.

In this article series, I summarize the watch features and markers that helped me peak at the right time for my target races during the 2025 spring/summer season. This particular article focuses more closely on sleep and the Polar Sleep Plus Stages™ feature.

This article was created with the support of Danubius Track Club and Polar Hungary. Danubius Track Club provides professional training conditions for countless athletes, while Polar’s cutting-edge technology – especially the Vantage V3 – enables modern, precise, and conscious training and recovery.

Monitoring Sleep Quantity and Quality – Polar Sleep Plus Stages™

Although countless recovery tools and techniques are available to anyone these days—such as cryochambers or lymphatic massage—good quality sleep and nutrition remain the two fundamental pillars of effective recovery. Human sleep has two main stages: non-REM and REM (rapid eye movement). The non-REM stage consists of three phases: dozing (easily roused state), light sleep, and deep sleep. During REM sleep, brain activity increases and dreams occur, accompanied by rapid eye movements. These three non-REM phases and the single REM phase form a cycle that lasts approximately 90–120 minutes and typically repeats 5–6 times per night.

The slow-wave deep sleep phase is particularly important for us because this is when growth hormone is released in the body. Growth hormone is essential for protein synthesis and therefore for cell regeneration and tissue building. In other words, high-quality and sufficient deep sleep is essential before a key competition—it ensures that the athlete is fully rested on race day. Unlike growth hormone, testosterone—another performance-defining hormone—is produced during the REM phase. Testosterone also plays a key role in tissue building and contributes to red blood cell production, thereby enhancing aerobic capacity.

The Polar Sleep Plus Stages™ feature evaluates your nightly sleep phases (such as REM and deep sleep) in percentage terms. Any value that falls below or above the reference range indicates a deviation from ideal sleep. These percentages contribute to the so-called sleep score calculated by the software. It’s useful to know that 25% REM sleep and 17% deep sleep represent the values required for a maximum sleep score. In addition to this, Polar Flow also displays the total time spent in each phase.

However, time spent in each sleep phase is just one component of sleep analysis. Total sleep duration is at least as important. Personally, I sleep about 9 to 9.5 hours during periods of heavy physical load, while during rest phases or demanding university periods, I average about an hour less. On the Polar Flow interface, you can view your current sleep duration as well as your average over the past 28 days. To peak at the right time, it’s essential to exceed this 28-day average in the three days prior to your target race. Life is all about compromises—so during the academic year, when I mostly participate in prep races or fitness-building events, I manage the data I see in Polar Flow more flexibly, knowing that sometimes I simply must stay up late to finish homework or study for exams.

Nonetheless, I am meticulous about getting fully rested in the three nights before a race. It’s not uncommon for me to sleep 10 to 10.5 hours on the ultra-soft and comfortable mattresses of hotel rooms in the night or two leading up to a competition. I always turn off or cover any blue or red light sources from electronic devices, completely darken the room, and often take 2–5 mg of melatonin gummies about 15 minutes before bedtime. Thanks to personal experimentation over the past few months, I’ve also found the optimal pre-sleep window to eliminate blue light—which inhibits melatonin (the sleep hormone) production. For me, this means sending my last email and shutting down my laptop about 30 minutes before going to bed, and silencing my phone.

The final element of the sleep score is sleep continuity. Fortunately, I rarely wake up during the night. Time spent awake is usually between zero and three minutes per night. Therefore, the actual duration of continuous sleep is a more important marker than total sleep time. That’s what I focus on and compare from day to day. Occasionally, it’s also worth checking the continuity score, which is rated on a five-point scale.

Sleep Timing: Why Bedtime Matters So Much

Getting enough sleep alone is not a guarantee of proper recovery—when we sleep is just as important. Our body's hormonal processes, such as the secretion of growth hormone and melatonin, follow the circadian rhythm, meaning they are regulated by our internal biological clock. This means that, for example, if we go to bed at 11:00 PM, hormone production still occurs naturally, but if we only fall asleep after midnight, the body may "miss" the optimal window for hormone secretion.

I’ve noticed that even if I sleep the same number of hours, when I go to bed after midnight, I usually feel less rested upon waking.

Handling Poor Sleep Before a Race

Perhaps every athlete has experienced it: even if they go to bed early the night before a competition, excitement, tension, or environmental changes caused by travel across time zones can make falling asleep difficult. In such cases, many people panic—yet a single bad night of sleep won’t ruin your peak performance.

There was a race I once ran after barely six hours of broken sleep. According to Polar Flow, my sleep score was around 60, and REM sleep made up only 15%. Despite that, I ran exceptionally well. Why did this happen? Because in the days leading up to the race, I consistently slept more than nine hours a night, and my 28-day sleep average was well above 8.5 hours. Sleep has a cumulative effect.

If you find yourself unable to fall asleep quickly, it’s best not to stress about the potential negative effects of sleep deprivation. Picking up a book or magazine almost always helps solve the problem, as reading naturally makes you drowsy. However, it’s not recommended to use your phone, as the blue light from the screen can further disrupt your ability to fall asleep. It’s also advisable to try breathing exercises. I, for instance, try to take deep breaths while focusing on the sensation of air flowing through my nostrils.