Heart & nervous system
Understand what your heart rate, rhythm, and recovery reveal about your health — and what keeps your heart and nervous system resilient.
Most read
August 11, 2026
What is a good HRV? An HRV chart by age and sex, and how to read your own number
There's no single good HRV number — it depends on your age, sex, and above all your own baseline. Rough RMSSD ranges by age, why comparing to others is meaningless, and how to actually tell if your HRV is healthy: your baseline and your trend.
September 14, 2026
How to Increase Blood Oxygen Level: Healthy Habits — and When Low Oxygen Means You Need a Doctor
Everyday habits that support breathing and circulation for healthy people — and the clear line where a low oxygen reading stops being a wellness goal and becomes a medical issue.
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Latest articles
How medications change your heart rate zones
August 12, 2026
HRV during sleep: why it's measured overnight and what it reveals about your recovery
August 11, 2026
Why does my HRV change so much day to day? (And when to actually worry)
August 11, 2026
What is a good HRV? An HRV chart by age and sex, and how to read your own number
August 11, 2026
Why is my HRV so low? What a low heart rate variability actually means
August 11, 2026
How to improve your HRV: what actually works, and how long it takes
August 11, 2026
Low resting heart rate: athlete's heart or something to worry about? How to tell
August 10, 2026
Why is my resting heart rate so high? The real causes, when to worry, and how to bring it down
August 10, 2026
What is a normal resting heart rate? The real range, by age and fitness — and how to read your own
August 10, 2026
Vagus nerve exercises: 7 that actually shift vagal tone (and the ones that just sound good)
August 6, 2026
What is the vagus nerve? How vagal tone, your parasympathetic system, and HRV actually connect
August 6, 2026
HRV by age: normal ranges by decade, why it declines, and how to read yours
August 1, 2026
What causes arrhythmias and heart palpitations? Triggers, underlying conditions, and when to worry
July 24, 2026
Heart arrhythmia and palpitations: what a racing, fluttering, or irregular heartbeat means — and when it's dangerous
July 24, 2026
The heart keeps score
July 24, 2026
Vagus nerve stimulation: how to reset your vagus nerve, and what the evidence shows
July 23, 2026
What causes high blood pressure? Primary and secondary hypertension explained
July 9, 2026
What is blood pressure? The definition of hypertension and what your numbers mean
July 6, 2026
How to take blood pressure at home: choosing a monitor and getting an accurate reading
July 6, 2026