Just measured my RHR and found it was lower than it had been so I queried it. This was Grok’s response:
A resting heart rate (RHR) is the number of beats per minute your heart makes when you’re completely at rest (e.g., first thing in the morning, sitting quietly after waking). Your recent measurement of 50 bpm at age 73 is exceptionally low — well below the typical adult range of 60–100 bpm — and it’s a strong positive marker given your training background.
Here’s a clear breakdown of the benefits of a low RHR (especially in the 40–60 bpm range for fit older adults), based on major studies, meta-analyses, and guidelines from sources like the American Heart Association, Harvard Health, and long-term cohort research.
Key Benefits of a Low Resting Heart Rate
Stronger Cardiovascular Efficiency & Fitness
A lower RHR means your heart pumps more blood per beat (higher stroke volume), so it doesn’t have to work as hard at rest. This is a direct sign of excellent cardiorespiratory fitness — the heart muscle is stronger and more efficient, just like in endurance athletes.
At 50 bpm, your heart is functioning at an elite level for your age (top percentile for 70+), reflecting the impact of your consistent HIIT (Wingates/Norwegian), weighted sessions, and overall activity.
Lower Risk of Cardiovascular Events & Mortality
Numerous large studies show an inverse relationship: higher RHR is linked to increased risk of heart disease, heart failure, sudden cardiac death, and all-cause mortality.
Every 10 bpm increase above ~60–70 bpm often raises all-cause mortality risk by ~8–13% and cardiovascular mortality by ~8–17% (meta-analyses across tens of thousands of people).
In mid-life and older adults, RHR >75–80 bpm doubles or triples early death risk in some cohorts.
Conversely, lower RHR (especially under 60–70 bpm in fit individuals) is protective — associated with reduced risk of heart failure, stroke, and premature death.
Your 50 bpm puts you in the lowest-risk category for these outcomes.
Marker of Longevity & Healthspan
Across mammals (including humans), species with naturally lower RHR tend to live longer. In humans:
Lower RHR correlates with better overall lifespan and reduced age-related decline.
In very old cohorts (85–95+), lower RHR is tied to greater survival odds and preserved function (independence, cognitive health).
While extreme bradycardia (under 40–45 bpm) can sometimes signal issues (e.g., conduction problems), 50 bpm in a fit, asymptomatic person like you is a positive longevity signal, not a red flag.
Reduced “Wear and Tear” on the Heart
Fewer beats per minute over a lifetime means less mechanical stress on the heart muscle and arteries. This contributes to slower progression of atherosclerosis, lower inflammation, and better autonomic balance (higher parasympathetic tone = better recovery/stress resilience).
Other Indirect Perks
Better metabolic health (lower risk of insulin resistance, diabetes).
Improved autonomic nervous system function (more parasympathetic dominance = calmer baseline state).
Reflection of high aerobic capacity (VO2max), which is one of the strongest predictors of longevity and reduced frailty in older adults.
Important Caveats for Age 70+
Normal RHR for most older adults is 60–80–100 bpm; yours at 50 bpm is athlete-level, not “average elderly.”
Very low RHR is usually beneficial only if asymptomatic (no dizziness, fatigue, fainting, shortness of breath, or chest pain). If any symptoms appear, get checked (e.g., for conduction issues or medication effects).
In the very elderly (85–95+), the protective association with very low RHR sometimes flattens or disappears in some studies — but you’re not there yet, and your fitness context makes 50 bpm a win.
Bottom Line for You
Your 50 bpm RHR is a fantastic biomarker — it’s evidence that your training (HIIT + weighted strength + daily activity) is delivering profound cardiovascular and longevity benefits. It means your heart is efficient, resilient, and working far less hard than average at rest. Keep tracking it (morning, same conditions); sustained low RHR like this is one of the clearest signs your protocol is supporting both strength preservation and healthspan extension.
If it ever drops below ~45 bpm or you feel off, mention it to your doctor — but right now, this is a massive green flag.
Keep owning those sessions, mate. You’re building elite-level cardio resilience at 73.
— Coach Grok
(Tom: Seems like it is a very good marker to keep track of and aim to improve.)