Suunto 2.50.26 – Q4 2025 Release Notes
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@DrSilverthorn Its not the HRmax that is used for Training Load in my experience, its the zones - especially the thresholds. And those you can set per sport
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@DrSilverthorn agreed.
Heart-rate–based training load metrics rely on normalizing effort relative to a reference such as maximum heart rate, implicitly assuming that a given percentage of HRmax represents a comparable level of physiological stress. In reality, HRmax is sport-dependent, varying with muscle mass involved, body position, contraction type, and neuromuscular recruitment; most athletes reach higher maxima in running than in cycling or other seated sports. Applying a single HRmax across multiple sports therefore misaligns intensity zones, systematically under- or over-estimating load for at least one activity and biasing cumulative metrics like weekly or chronic training load. This error is not random but structural, making cross-sport load comparisons unreliable and increasing the risk of hidden fatigue. For multi-sport training, sport-specific HRmax values or preferably sport-specific thresholds are required for physiologically defensible load estimation.
SR, SVti (Mammut Edition), SR2, Suunto Wing
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@BastMaSVSRS9PP said in Suunto 2.50.26 – Q4 2025 Release Notes:
@DrSilverthorn agreed.
Heart-rate–based training load metrics rely on normalizing effort relative to a reference such as maximum heart rate, implicitly assuming that a given percentage of HRmax represents a comparable level of physiological stress. In reality, HRmax is sport-dependent, varying with muscle mass involved, body position, contraction type, and neuromuscular recruitment; most athletes reach higher maxima in running than in cycling or other seated sports. Applying a single HRmax across multiple sports therefore misaligns intensity zones, systematically under- or over-estimating load for at least one activity and biasing cumulative metrics like weekly or chronic training load. This error is not random but structural, making cross-sport load comparisons unreliable and increasing the risk of hidden fatigue. For multi-sport training, sport-specific HRmax values or preferably sport-specific thresholds are required for physiologically defensible load estimation.
Tell that to Coros and his “One HR zones for all”…
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@BastMaSVSRS9PP said in Suunto 2.50.26 – Q4 2025 Release Notes:
Heart-rate–based training load metrics rely on normalizing effort relative to a reference such as maximum heart rate, implicitly assuming that a given percentage of HRmax represents a comparable level of physiological stress.
Possibly this assumption of percentage of HR max is used as the reference isn’t correct after all? If Suunto uses HR zones for training stress calculation, then those are the reference…
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@jjpaz Or see Polar’s implementation where you can set maxHR and zones for each sport profile.
This is the way to go.
I did a stress test in a laboratory on a bike and my maxHR was 10 beats lower than during a running session. My cardiologist assured me that this was normal because cycling is a low-impact sport that does not engage as many muscles as running. -
@Raphes67 yeah, but it is the maximum HR that you reached by doing that sport not the maximum HR your heart can actually do. The latter one keeps the same.
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@2b2bff yes you’re right, I have a physiological max heart rate that is reached during running (in my case 184). But when I cycle, I know that I can never reach this max heart rate and 174 would be my max for this sport. That’s why for any cycling profile I have to set a different max heart and different zones according to this knowledge to reflect the real effort and recovery metrics that are dependent.
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@Raphes67 so what is the problem? MaxHR is maxHR that is the limiti, also Suunto allows to change cycling zones to reflect your ability to only reach lower HR for cycling.
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@aiv4r
Hi, in this latest update (in my particular case), when you change or modify the Maximum Heart Rate for cycling, it also modifies the heart rate for other sports (running, default, etc.). This could be a bug to consider. I think I’ve modified it in previous updates, and each sport had its own custom heart rate zones…
Hence all these tips, contributions of maximum heart rate in different disciplines… -
@Elmiuel yea I do not think it is a bug, maxHR is maxHR and I think suunto focus on one physiological maxHR (it is only one). So when changing zones in cycling just change zone limits themselves not the mac HR. I think it is supposed to work like that.
