Suunto Blog

Yao Miao has always known how to run. But becoming a better athlete isn't simply about running more. Over the past year, she has changed the way she trains — moving from relying on instinct and experience to building a more structured, professional approach. “Only through competition can you find a stronger version of yourself.” A More Complete System Today, Yao's training goes beyond running. With support from her coach and specialists in strength, nutrition and recovery, every part of her preparation has a purpose — from building strength and climbing ability to improving her speed and technical descents. The goal isn't simply to train harder. It's to train better. From Pace to Heart Rate When Yao first started training, she mainly focused on pace and distance. Today, heart rate has become a much more important part of her training strategy. Her training plans and race strategies are built around heart rate, helping her understand how hard she is actually working and how to manage her effort. For Yao, relying only on how her body feels isn't always accurate. The data gives her another layer of feedback — helping her control her pace, manage her effort and make better decisions throughout training and racing. Her Suunto watch puts that information on her wrist, turning every session into a clearer picture of how her body is responding. The data informs the strategy. Yao makes the decisions. Stronger Through Competition For Yao, racing is more than a test. It's a way to discover what she can improve. Every competitor, every difficult section and every race reveals another opportunity to become stronger. Her love for running hasn't changed. What changed? The way she trains to become better.

Toni McCann knows Chamonix well. She won the UTMB OCC in 2023, then stepped up to the UTMB CCC in 2024 and took the win. After not finishing the race in 2025, Toni is returning to the UTMB CCC in 2026 — but with a different mindset. “Just run for me, instead of running for other expectations.” For Toni, the past year has been about stepping away from the pressure of results and reconnecting with why she runs in the first place. A different approach Success can bring expectations. After winning in Chamonix, the pressure to perform can become part of the race itself. This time, Toni is focusing on her own process — enjoying the training, trusting her preparation and taking on the challenge on her own terms. Her preparation combines running, strength work, cycling, recovery and time in the mountains. Rather than focusing only on performance, she is also learning to listen to her body, knowing when to push and when to recover. Training and racing with Suunto Her Suunto Race 2 is part of that process, helping her understand both her body and the course. With HRV-based recovery insights, Toni can monitor how well her body is recovering and make more informed decisions about her training. Combined with heart rate and Climb Guidance, Suunto helps her prepare for the physical and mental demands of the UTMB CCC. The technology provides the information. Toni makes the decisions. Back to Chamonix The CCC course hasn’t changed. But Toni’s relationship with it has. This time, there is less pressure to prove and more freedom to run — on her own terms, for herself. What changed? The reason she runs.

Take on the climb. Earn the rewards. Take on the Suunto 90 Segment Challenge in Chamonix during the UTMB World Series Finals. Set on a section of the iconic Chamonix Vertical Kilometre course, this short, steep climb below the Brévent lift puts your legs to the test. JOIN ON STRAVA NOW Its 90-metre ascent is a nod to Suunto’s 90th anniversary and a taste of one of Chamonix’s iconic vertical challenges. It’s short enough to take on even when you’re saving your legs for the week’s races. Complete the segment and you’ll unlock a 15% discount at suunto.com and a chance to win a Suunto Race 2. And there’s more. From Monday to Thursday, August 24–27, the first 10 people each day to complete the segment and visit the Suunto booth at the Ultra-Trail Village will receive a Suunto gift. Be there early! HOW IT WORKS 1. Join the ChallengeJoin the Suunto 90 Segment Challenge on Strava. 2. Take on the segmentRun or hike the segment, record your effort and sync it to Strava. 3. Claim your rewardsAfter completing the Challenge, claim your reward to receive the Challenge badge, your 15% discount at suunto.com and a chance to win a Suunto Race 2. 4. Get your Suunto giftComplete the segment on August 24–27 and be among the first 10 people each day to visit the Suunto booth at the Ultra-Trail Village to claim a surprise Suunto gift. CHASE SEGMENTS. SEE YOUR PERFORMANCE. Want to know exactly how you’re doing while chasing a Strava Segment? With SuuntoPlus Segments, you can see your segment performance in real time right on your wrist, helping you pace your effort and push for your best. Learn more about chasing Strava Segments with Suunto Terms and conditions apply. Learn more here.

Ida-Sophie Hegemann knows what it takes to adapt. From track running in flat northern Germany to living in Innsbruck, she has built her life around mountain trails. After last year’s finals, Ida realized that staying in her comfort zone was no longer enough—and to elevate her performance for Chamonix, everything had to change. “Are you really stepping out of your comfort zone when you’re writing your own training schedule?” For Ida, the past year has been about surrendering total control, embracing professional structure, and seeking out the discomfort needed to grow. Choosing Discomfort Self-coaching brought Ida far, but pushing to the highest level required external challenge. This time, Ida is trusting a new team—working with a new coach, a mental coach, and professional management to push her limits beyond what she would set for herself. Her preparation means embracing severe suffering: higher volume, weighted vest workouts, steep road repeats outside her home, and relentlessly targeting her biggest weakness—technical downhills—until it became a strength. Proof of Progress Suunto watch is an essential part of tracking that evolution. By analyzing her Suunto training logs, Ida compares current sessions against past years—seeing clear proof of higher elevation gains, faster speeds, and measurable progress. The data confirms the work is paying off when the training gets tough. From track running in flat northern Germany to living in Innsbruck, she has built her life around mountain trails. After last year’s finals, Ida realized that staying in her comfort zone was no longer enough—and to elevate her performance for Chamonix, everything had to change. Technology tracks growth. Ida delivers the performance. Ready for What’s Next The UTMB course hasn’t changed. But Ida’s preparation for it has. This time, she arrives with technical downhill confidence, a sharper mindset, and the strength of a fully professional system behind her. What changed? The depth of her preparation.

For endurance sports such as marathon and trail running, getting faster isn't simply about training harder. Long-duration performance depends on your body's ability to sustain energy production, handle training volume, and maintain a steady output over time. Through low-intensity, sustained aerobic work, Zone 2 training helps build this foundation. This article explains how to find your Zone 2, understand the principles behind it, and incorporate it effectively into your training plan. At a glance Zone 2 is a low-intensity aerobic training zone. Its primary value lies in building a strong aerobic foundation. There is no single method for finding your individual Zone 2. Zone 2 should be part of a complete training plan, not the entire plan. The benefits of Zone 2 are primarily seen through long-term changes. Consistency matters more than short-term intensity. What Is Zone 2 Training? Zone 2 is a training intensity zone defined by heart rate. In the commonly used five-zone heart rate model, training intensity is divided into different zones based on an individual's heart rate data, with Zone 2 representing a low-intensity aerobic zone. Different training systems may use data such as maximum heart rate (HR max) or lactate threshold to determine these zones. What Should Zone 2 Feel Like? In practice, heart rate isn't the only way to gauge intensity. Your perceived effort can also help you identify whether you're in Zone 2: Comfortable conversation without catching your breath Heavier breathing, but still manageable Finishing the workout with plenty left in the tank Why Does Zone 2 Feel So Slow at First? When many runners first start Zone 2 training, their pace drops noticeably, and they may even need to use a run-walk approach. Early in training, aerobic efficiency and the ability to use fat for fuel are not yet fully developed. At higher paces, the body relies more heavily on glycogen, causing heart rate to rise quickly. With consistent training, you'll gradually notice improvements such as running faster at the same heart rate and experiencing less fatigue after long runs. Why Zone 2 Training Matters for Running The value of Zone 2 training lies in the adaptations it supports across several key aspects of endurance performance, including improving aerobic capacity, increasing sustainable training volume, and supporting higher-intensity training. Build a Strong Aerobic Foundation The primary role of Zone 2 training is to gradually improve the body's ability to produce energy aerobically over time. During low-intensity, sustained exercise, the body continuously relies on oxygen to produce energy. With consistent training, the muscles gradually adapt, including an increased capacity for fat oxidation, allowing the body to use fat more effectively as a fuel source during prolonged exercise. In simple terms, the body becomes more efficient at sustaining the same level of exercise. Increase Training Volume with Less Fatigue Endurance gains depend not only on the stimulus from individual workouts, but also on how much effective training you can consistently complete over time. Compared with high-intensity training, Zone 2 places less stress on the muscles and metabolic systems, which generally means a shorter recovery time. This allows runners to gradually increase training frequency and volume without continually accumulating excessive fatigue. Over time, greater training consistency means more opportunities for the body to adapt, leading to continued training improvements. How to Find Your Zone 2 Heart Rate Zone 2 is not a fixed heart rate number. It can vary depending on factors such as maximum heart rate, lactate threshold, aerobic fitness, and training level. Runners can therefore use different methods to find the Zone 2 range that works best for them. Traditional Calculation Traditional calculation is one of the most common starting points and typically estimates Zone 2 based on maximum heart rate. Zone 2 is generally around 60–70% of maximum heart rate, but because maximum heart rate varies between individuals, age-based formulas are best used as an initial reference. Lactate Testing One of the more accurate ways to determine Zone 2 is to identify your lactate threshold (LT). Lactate threshold represents the point at which the body transitions from a relatively stable aerobic state to a state where blood lactate begins to accumulate more rapidly. The most direct approach is laboratory lactate testing, which measures changes in blood lactate during an incremental exercise test and uses the resulting lactate curve to determine LT. For recreational runners, lactate threshold can also be estimated using indirect tests such as the 30-minute Time Trial, VDOT, and Conconi Test. These methods do not directly measure lactate, but instead indirectly estimate LT using factors such as heart rate, pace, or performance. Once LT is established, you can determine the corresponding lactate threshold heart rate (LTHR). Depending on the training zone model being used, LTHR can then serve as a reference for defining heart rate zones and determining your Zone 2 range. Heart Rate Drift Test The Heart Rate Drift Test is more practical for everyday training. During a sustained low-intensity run, keep your pace relatively steady and observe how your heart rate changes in the second half. If heart rate remains relatively stable, the intensity is generally within a suitable aerobic range. This method requires no laboratory testing, but can be affected by factors such as weather, fatigue, and hydration. Talk Test and Perceived Effort The Talk Test is one of the simplest ways to gauge intensity based on perceived effort. Zone 2 generally feels like an intensity where you can speak in full sentences and carry on a simple, natural conversation. Using Suunto Products Suunto products can make heart rate training easier to apply in practice. Suunto can automatically set default heart rate zones based on maximum heart rate, while on Suunto Run, runners can choose between maximum heart rate, heart rate reserve, and lactate threshold heart rate zone models. You can also customize your heart rate zones to better match your training needs, while Suunto App lets you track long-term changes in heart rate, training load, and recovery to better understand your Zone 2 progress. How to Use Zone 2 Training in Your Running Plan After learning about Zone 2, many runners may wonder: “Should all my training be Zone 2 from now on?” The answer is no. Zone 2 is the foundation of endurance training, but it is not the whole picture. The 80/20 Training Principle Many endurance athletes follow a roughly 80/20 approach, with around 80% of training performed at low intensity (Zone 1–2) and 20% at higher intensities. This structure allows runners to build their aerobic base while maintaining enough high-intensity stimulus to develop speed and race performance. Balance Weekly Training Volume In your training plan, gradually building endurance often means increasing training frequency rather than simply making individual workouts harder. A Rest/ Deload Week every 3–4 weeks can also help reduce accumulated fatigue by temporarily lowering training volume. By balancing training volume with adequate recovery, you can better manage your weekly workload and avoid increasing your training load too quickly. Adjust Zone 2 Intensity Based on Conditions Zone 2 training does not mean maintaining the same pace in every session. Heat, humidity, poor sleep, fatigue, dehydration, and low energy availability can all cause heart rate to rise. Rather than pushing harder to maintain your usual pace, adjust your intensity based on how you feel that day. During longer sessions, make sure to replenish fluids, carbohydrates, and electrolytes to maintain training quality. Use Run-Walk Strategies When Needed For trail runners, keeping the intensity in Zone 2 is generally more challenging than road running. In environments like steep climbs, high altitude, and technical terrain, heart rate can quickly rise. In these situations, slow down or even switch to brisk walking to keep your heart rate within the target zone. As long as the intensity is appropriate, walking can still provide an effective Zone 2 workout. How to Know Your Zone 2 Training Is Working The benefits of Zone 2 training usually do not appear as quickly as the effects of a single high-intensity workout. Instead, they are reflected in gradual improvements in efficiency over time. Runners can look for several signs that their Zone 2 training is working: Heart Rate and Pace Improvements One of the clearest signs of progress is running faster at the same heart rate, or maintaining the same pace at a lower heart rate. These changes indicate that your body is becoming more efficient at handling the same exercise load and that your aerobic efficiency is improving. Better Recovery and Training Consistency The value of Zone 2 is not only reflected in individual runs, but also in your ability to handle training load over time. As your aerobic base improves, you may find that you recover faster after long runs and feel less fatigued the following day. For Suunto users, training load, recovery status, and long-term heart rate trends can help you track how your body is adapting to training. Learn more about Recovery here. When Will You See Results? The benefits of Zone 2 training take time to build rather than appearing overnight. Some runners may notice that running feels easier and their heart rate is more stable within a few weeks, while 2–3 months of consistent training may bring more noticeable changes in pace and long-distance endurance. More significant improvements in endurance typically take several months or longer, making Zone 2 a long-term training approach. TAKEAWAY The value of Zone 2 lies not in deliberately slowing down, but in using consistent training over time to build a stronger aerobic system and greater training capacity. For marathon and trail runners, consistent accumulation matters more than pushing to the limit every time, helping create a stronger foundation for running faster, farther, and more consistently. Next time you run, pay a little less attention to your pace and a little more attention to whether your body is becoming more efficient and more resilient. FAQS Can You Still Get Benefits from Zone 2 Training If You Have to Walk? Yes. For beginners, trail runners, and those training at high altitude, a run-walk approach can be an effective way to stay in Zone 2. The goal is to stimulate the aerobic system, not to maintain continuous running. As long as your heart rate and exercise intensity remain within the target range, brisk walking can still provide an effective Zone 2 workout. Are Zone 2 Heart Rate Zones the Same for Running and Cycling? Not necessarily. Cycling uses different muscle groups, involves less weight-bearing, and has different movement demands than running. For many people, maximum heart rate is also lower when cycling than when running. For this reason, it is best to determine your Zone 2 separately for running and cycling. Can Zone 2 Training Alone Help You Run a Faster Marathon? It can improve your aerobic foundation, but it is not a complete training plan. Zone 2 can help build endurance, increase training volume, and support recovery. However, marathon performance also requires other types of training, including: Marathon-pace training Threshold training Fueling strategy practice The best results come from combining different types of training rather than relying on Zone 2 alone.

Every Heartbeat Matters: A New Heart Rate Algorithm for Suunto Run You are eight kilometers into a tempo run, holding what feels like the right effort, and you glance at your wrist to check that you are where you want to be. It tells you whether to hold the pace, ease back, or press a little harder. When you train by heart rate zones, every reading feeds a decision. Runners have told us how closely they watch that number, and how much it matters that it reflects what their body is actually doing. We have been listening. On August 20, 2026, Suunto Run receives a firmware update with an all-new wrist heart rate algorithm, developed by Suunto, built to make your running heart rate more accurate and more worth acting on. What Is New in This Update A new firmware version for Suunto Run, releasing August 20, 2026. An all-new wrist-based heart rate algorithm, developed in house by Suunto. Focused specifically on heart rate accuracy while running. The interface and the way you use your watch stay exactly as they are. Free, and delivered straight to the watch you already own. This is an improvement to how your watch reads and interprets your pulse, not a redesign of how you use it. There is one thing to do: install the update. What This Means on Your Next Run Wrist heart rate works by reading blood flow through the skin, and running is a demanding environment for that measurement. Arm swing, changes in pace, cold weather and the sharp climb in effort at the start of a session all make the signal harder to read cleanly. The new algorithm is designed to handle those moments better. In practice, that means: Fewer readings that clearly do not match the effort you are putting in. A more dependable view of how your body responds through a session. More confidence when you use heart rate zones to steer intensity. A more reliable data foundation for managing your training load over time. For runners who work to zones, that last point matters most. A zone-based session only works if the number driving it holds up, and this update is about strengthening that foundation. What the Data Shows Suunto ran internal comparative testing across a range of running scenarios, measuring Suunto Run against a reference heart rate device. Data points that deviated by more than 5 bpm from the reference device were reduced by approximately 45 percent compared with the previous algorithm. In plain language: across the test data, the readings that stood noticeably apart from the reference device became considerably less common. The improvement shows up in the outliers, in the moments where the number on your wrist looked out of step with the run you were having. Full figures and testing detail are in the Testing Notes at the end of this article. Based on Suunto internal testing against a reference heart-rate device. Results may vary depending on the user, activity and wearing conditions. How to Get the Update Installing takes a few minutes: Update the Suunto app on your phone to the latest version. Make sure your watch has enough battery to complete the installation. Connect Suunto Run to the Suunto app and check for a software update in the app or on the watch. Follow the on-screen prompts to complete the installation. The update will be rolled out gradually. Availability timing may vary by market and user. Getting the Best from Wrist Heart Rate A few habits help your watch read you well, whichever algorithm is running: Keep the watch in steady contact with your skin, with the strap snug enough to stay in place while you run. Remember that wearing position, skin condition, ambient temperature and the type of movement can all influence a wrist-based reading. For sessions where you want the most detailed heart rate data, pair Suunto Run with a compatible heart rate belt. Wrist heart rate is a training tool, and a good one. It is not a medical device, and it is not designed to replace one. Every Reading, Taken Seriously You care about every heartbeat. We take every reading seriously. Update your Suunto Run and get more accurate, more dependable heart rate data on your next run. Testing Notes Suunto conducted internal comparative testing of the new and previous wrist heart rate algorithms across multiple running scenarios, using a reference heart rate device as the comparison benchmark. Data points with an error greater than 5 bpm: 7.394 percent with the previous algorithm, 4.036 percent with the new algorithm, a relative reduction of approximately 45 percent. Accuracy within ±5 bpm: improved from 92.606 percent to 95.964 percent. Accuracy within ±10 bpm: improved from 96.468 percent to 97.803 percent. These results come from Suunto internal testing and are not an independent third-party certification. A reference heart rate device serves as a comparison benchmark rather than an absolute measure of heart rate. Results may vary depending on the user, activity and wearing conditions.