@spikesonly
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Scientific journals are contributing to the illusion that consumer wearable PPG devices are valid HRV research tools, which benefits brands while misleading everyone else.View quoted post on X
My concerns with this study:
🚩RMSSD was estimated via Whoop, not measured with ECG
🚩 Whoop has not been rigorously independently validated for HRV
🚩 According to their website, Whoop’s proprietary HRV metric is weighted to later phases of slow wave sleep, which likely misses the short-term effect of feeding on HRV that would occur post-ingestion
🚩 100 ms is high for a group mean
🚩 Every other wrist/ring wearable PPG device that has been independently tested shows much greater estimation error at higher HRV
🚩 Feeding can alter peripheral vascular tone and BP, potentially affecting whoop/PPG estimation of RMSSD via changes in pulse arrival time rather than cardiac-ANS modulation. Thus, ECG is needed.
🚩 While a small liquid serving may not substantially affect HRV like a solid mixed meal would, we don’t really know how HRV was affected in this study based on the above comments
I like the study idea but disagree with the HRV methods. I’m less familiar with the validation research for the other sleep metrics from Whoop but a quick search showed disappointing results for this model.
My favorite fall workout, sprints and woodsplits. No gym equipment required.View quoted post on X
The most baffling part of this NBA injury discourse is teams are looking at their injuries going up year after year while they continue to do more load management and cut preseason ramp upView quoted post on X
At what point do they put two and two together and think “hm, maybe we need to do the opposite of what we keep doing every year?”
What’s that quote about the definition of insanity?
